Geography of Hazards 2152

- Dense oceanic plates sink and melt - The melted magma rises to form mountains and volcanoes (eg: Andes) - Collisions involving two continental plates result in collision boundaries: - Neither plate sinks and both are forced upwards - Tall mountains tend to form (eg: Himalayas) - Transform Boundaries - At these boundaries, plates slide horizontally past each other - Associated with earthquakes - The zone along which the movement occurs is called a transform fault - Most of these faults are located beneath oceans, but some occur on continents - Ex: San Andreas fault that causes splitting of California in the future - Hot Spots - These areas are somewhat random and found away from plate boundaries - They are spots where magma rises from the mantle due to stronger currents - Magma erupting at the surface results in the formation of volcanoes - Strings of islands are usually indicative of a hotspot - Ex: Hawaiian islands; fixed plume of magma but the tectonic plates slide past, where the sliding action of the plates allows consecutive volcano/land formation - Only the volcano that is situated above the hotspot will erupt - The Rock Cycle - A rock is an aggregate of one or more minerals - The rock cycle refers to a group of interrelated processes that produce the three different rock types: igneous, sedimentary, metamorphic - Igneous rocks give information about volcanic events; cooled magma - The type of rock in an area gives clues to geological events of the past - The Hydrologic Cycle - The movement and exchange of water among the land, atmosphere, and oceans by changes in state (evaporation, condensation, precipitation, freezing) - Also referred to as the water cycle - Solar energy drives the movement of water among the atmosphere, oceans, continents - The residence time of a water molecule ranges from days (in the atmosphere) to thousands of years (in the ocean); all water will eventually make it back to the ocean - Major Course Themes - Hazards can be understood through scientific investigation and analysis - An understanding of hazardous processes is needed to evaluate risk - Hazards are linked to each other and the environment - Population growth and socio-economic changes are increasing the risk of hazards - The consequences of hazards can be reduced - Theme 1: Hazards can be Understood - Scientists observe a hazardous event and form a possible explanation for the cause - From this explanation, a hypothesis is formed

- Three Mile Island nuclear meltdown - A, B, D are disasters as defined below - Defining Disasters - What events qualify as a disaster? - A threshold has been developed by the Centre for Research on the Epidemiology of Disasters (CRED): - 10 or more deaths per events - 100 or more persons affected (injured, homeless, etc.) - Or government declaration of disaster - Or plea for international assistance - Exceptions to CRED threshold: - For droughts or famines, at least 2000 people affected - For technological disasters, 5 or more deaths per event - Disasters and Statistics - Statistical data is reported in absolute terms (number of casualties, billions of dollars of damage, etc.) but the impact of losses is felt differently from one place to the next - Example: 10 fishers lost in a remote village of 200 people versus 10 factory workers in a city of 200,000; the same death toll in both situations but the small remote village will have a greater psychological/social toll to the disaster - Therefore, statistics must be placed in a community context - Media and Disasters - The media tends to concentrate on: - Human interest - Visual impact (earthquakes, tornadoes, hurricanes) - Events prioritised according to North American perspective - In terms of North American media attention, a study found that an event causing the death of one North American was granted the same amount of reporting time to the deaths of: 3 Eastern Europeans or 9 Latin Americans, etc. - Disasters and Impacts - Impacts vary greatly by disaster type - Earthquakes tend to cause more deaths than tornadoes - Floods affect more people (homelessness) than most disasters but cause fewer deaths than other disasters - Droughts mainly cause economic losses (agriculture) in developed countries but they can lead to famine in developing countries - Technological disasters are more likely to occur in developed countries - Disaster Impact Trends - Globally, most impacts from disasters have increased over time: - Property damage - Economics losses - Persons injured - Deaths

- Be under control versus controlled by others - Have clear benefits versus little or no benefit - Be natural versus anthropogenic - Be statistical (common) versus catastrophic - Be familiar versus exotic - Affects adults versus children - Improving Our Risk Perceptions - Carefully evaluate what the media presents - Compare risks (question is not ‘is it safe’ rather ‘how risky is it compared to other risks’?) - Concentrate on the most serious risks to your own health and don’t worry over risks which you have no control - The Changing Nature of Risk - There has been a shift in risks over the last few generations: - Shift from infectious disease toward chronic degenerative diseases - Accidents in the workplace becoming more rare due to safety regulations - Death rates from natural disasters are generally lower than they were in the past in developed countries - As technology has advanced, it has introduced new hazard threats - Nuclear power plants, chemical spills, pesticides, ozone depletion, acid precipitation - An increased role of the government in risk assessment and risk management; departments specifically devoted to disaster relief, traffic safety, public health - There has been an increased involvement of lay people in risk management decisions such as Greenpeace, Sierra Club. and social media - As countries transition from developing to developed, there are increased expectations on their government from the public - This creates pressure on governments and sometimes expectations of the people can be unrealistic depending on the wealth of the country Japan 2011 Earthquake and Tsunami Documentary 1. Explain how the interaction between the Eurasian plate and the Pacific plate led to the earthquake. How long does this interaction occur before a major earthquake happens? - Japan is on the Eurasian plate; the Pacific plate is forced to travel underneath at the tectonic plate boundary and this energy had been building up for hundreds of years; around 200 years for this particular earthquake Eurasian plate is dragged downwards by the Pacific plate as it travels underneath, the rebounding of the Eurasian plate causes the emergence of tsunami 2. How did the geography of the land around Sendai enhance the destruction in that region?

- Effects of Tsunamis - Primary effects - Flooding and erosion - Destruction of beaches, coastal vegetation, and infrastructure - After the tsunami retreats to the ocean, scattered debris is left behind - Most tsunami deaths are from drowning and injuries result from physical impacts with flowing debris - Secondary effects (effects that generally occur after the event is over) - Fires may develop due to ruptured gas lines/ ignition of flammable chemicals - Water supplies may become contaminated and water-borne diseases (cholera) may spread (especially in developing and lesser developed countries) - Indian Ocean Tsunami of 2004 - Catastrophic event occurred on Dec 26th - Source was a M 9.1 earthquake off the west coast of Sumatra (an island of Indonesia) - It was the 3rd strongest earthquake in world history - Occurred in a subduction zone between the Burma and Indian-Australian plates - These plates had been locked for over 150 years thus allowing immense strain and pressure to build up and the rupture caused some land areas along the coastline to subside/sink below sea level - The tsunami reached nearby Indonesian islands within minutes of the earthquake - No warning systems set up in the entire Indian ocean causing many deaths in the surrounding areas; there were many casualties even in Africa - Many coastal communities in Indonesia and the surrounding countries were devastated - Countries bordering the Indian Ocean did not have a tsunami warning system like those bordering the Pacific Ocean; people were caught by surprise and over 230,000 died - Many were unfamiliar with tsunamis and some were intrigued by the approaching waves and would move towards the coastline - Most people in the area were ignorant of an early warning sign (receding sea) - Lessons from the 2004 Tsunami - Effective tsunami warning systems are needed around all oceans where tsunamis can occur, in 2006 a new warning system became operational in the Indian Ocean - However, a warning system by itself is not enough… why? - Emergency officials must have an organized plan for evacuating residents during a warning - Earthquake and tsunami education is necessary for people who live along or visit coastlines - Detecting Tsunamis - The Pacific Ocean warning system uses a network of seismographs to estimate earthquake magnitude - Sensors electronically connected to buoys verify that a tsunami was produced - These sensors are called tsunameters

- Example: advances in technology have improved our hazard warning systems - Absorptive Capacity - This is a measure of the ability of people to sustain impacts from a hazard - It results from combinations of cultural, purposeful, and incidental adjustments - Example: In parts of Kenya, maize, beans, peas, sorghum, and groundnuts are all planted together instead of planting them into separated rows - This forces the plants to compete with each other for nutrients, thus only the strongest crops that have the best deep and drought resistant roots will survive and persist → drought resistant crop yield - Ordered Choice Decision Making - Look at example on slide - Decision is made by nullifying other choices until the most optimal choice is left - Cognitive Influences on Choice - Based on 100 years of past data, the estimated probability of a 100-year tornado touching down in Disaster Town in 2022 was 0.01; in 2022 it did touch down - The likelihood of a 100-year tornado is - Gambler’s Fallacy - The belief that the occurrence of a chance event influences the probability of future occurrences; independent events are confused for sequential events - Theory of Choice - Based on the information, would you choose to evacuate or remain? - Number 0 is always assigned to worst-case scenario in the matrix, Number 2 is always assigned to the best-case scenario in the matrix, 1 is assigned to the intermediates - Probability multiplied by number value gives the utility value from each scenario - Ex: 40% chance that hurricane hits 0.4 for hitting, 0.6 for missing ⇒ - Finally, add utility values from each scenario within a row to find the expected utility value for a given situation; the situation with the highest expected utility value should be the decision for the given scenario - Expected Utility

- Entire countries, technologies (medications), industries (meat) can be affected - Ex: mad cow disease in Alberta affecting beef industry - Secondary impacts - Property values and insurance rates may change in response to an event - Risk perception Theories - Research Question: Why do some people feel that some technologies (eg. nuclear energy or pesticides) are a major concern while other people feel that they are not? - Knowledge Theory - Theory tested by education level and self reported knowledge - People were asked to provide an estimate of annual fatalities from 8 technologies (aviation, nuclear, energy, lawn mowers, etc.) Their answers were then compared to actual fatality data - Hypothesis: greater knowledge of fatality data leads to a greater perceived threat from the technology and vice versa - Personality Theory - Tested using validated measures and questionnaires developed by psychologists - Hypothesis: there is consistency between personality type and the perceived threat from technological hazards (eg. type A personality is more cautious than type B) - Economic Theory - This theory is based on the annual income of the people tested - Hypothesis: the wealthy people are more willing to take risks with technology because they may benefit more or have better access to that technology - The poor are less willing because they may deal with any associated burdens - Political Theory - This theory was tested by determining the political ideology of the subjects through the completion of a 20-question survey - Hypothesis: personal views toward risk are related to the political party (and policies) that the person supports - Cultural Theory - This theory is based on the way of life of a person (urban, rural, retired, child-rearing) - It is supported by personal worldviews (ie. the way the person believes the world operates or should operate) - Examples of worldviews: hierarchical, egalitarian, individualist - Hierarchical Worldview: defines boundaries between superiors and subordinates - Examples of this view: - Strong patriotism and support for country - Strong respect for authority (law, order, and obedience are strongly valued in this worldview) - Strict ethical standards - Concern about lack of discipline in youth - Egalitarian Worldview: centers on political solutions to inequality

- The forces are determined by relationships among material type, slope and topography, climate, vegetation, and water - Role of Material Type - Low consolidation + the presence of weakness planes can increase the risk of landslides - Slumps are most common in unconsolidated sediment - Slumps are rotational mass movements as opposed to translational mass movements - Rotational: material falls along a curve surface - Translation: material falls along a discrete plane (ex: slide) - Translation movements often occur where sediment overlays bedrock; the failure plane is generally at the boundary between the soil and the bedrock - Role of Slope and Topography - The steeper the slope, the greater the driving force - Steepest slopes are associated with rock falls - Moderate slopes are associated with flows - Gentle slopes are associated with creep - Topographic relief: the height of a hill or mountain above the land around it (that same hill/mountain); dangerous landslides are more likely in areas of high relief - Role of Climate - The climate of an area influences the amount of water that infiltrates and erodes the soil - In dry climates, vegetation is sparse, soil is thin, and bare rock is exposed in many areas - Rock falls are more likely in those areas - In humid climates, soil is thick, and rock is generally covered with soil and vegetation - Thus, flows and creeps are more likely in those areas - Role of Vegetation - Dense vegetation can slow surface erosion - Roots add strength and cohesion to the soil of the slope - Therefore, improper deforestation often increases the frequency of landslides - Ex: Massive deforestation in Haiti - Role of Water - Water saturates soil increasing the likelihood of flows (through driving force) - Following prolonged periods of deep-water infiltration, slumps can develop - Water can also erode the base of a slope therefore decreasing its resisting force - Regions at Risk - Any location with significant variation in topography is at risk - The Frank Slide - It is Canada’s most well-known landslide - It occurred in 1903 on Turtle Mountain near Frank, Alberta - Killed 76 people, dammed Crowsnest River creating a lake, and buried 5 km of railway - The exact cause of the landslide is unknown but glaciation, coal mining, and heavy snows (melting) are likely contributors - Effects of Landslides

- Approximately 30 people are killed by landslides annually in North America - Landslides can block railways and highways in isolated areas, severely impacting travel - As urban areas continue to expand, property damage will increase - Natural Service Functions of Landslides - Landslides can result in the development of new habitats - If a landslide blocks a river from flowing, a lake will form creating a new aquatic ecosystem; this produces an increase of biodiversity - Landslides can carry sediments that contain valuable minerals which become concentrated at the base of the slope following an event - Old landslides allowed us to discover where valuable minerals were located before we had the technology to discover them - Human Interaction with Landslides - Grading of land surfaces (flattening) for new home and building construction can increase probability of slope failure (especially near slopes) - Deforestation and urbanization are currently the leading human causes for the increase in landslides - Deforestation - Clear-cutting and the construction of logging roads can cause landslides in geologically unstable areas - A lack of surface vegetation and lack of tree roots enhances soil erosion and landslides - Urbanization - Modern engineering has allowed us to turn hilly slopes into flat land for construction - Slopes are destabilized when rock is moved, lawns are watered, septic systems are installed, and buildings are constructed; additional weight increases the driving force - Minimizing the Landslide Hazard - An important first step is recognizing where they are most likely to occur - Features indicative of unstable slopes include: - Cracks on a hillside - A recessed crest in a valley wall - Large boulders or talus at a cliff base - Talus: fragments of rock that have moved down a slope and accumulated at its base - Tilted trees - Exposed bedrock (soil has already slid off) - An irregular land surface at a slope base - Aerial photos are used to detect some of these features and then hazard maps can be produced based on this information - Prevention of Landslides - Complete prevention is impossible; certain engineering practices can minimize - Drainage control - The objective is to remove excess water from the soil with pipes and drains - Commonly performed if road or railway is nearby

- Leveling the Slope - Material from the upper slope can be moved to the slope base with modern technology thus minimizing the risk of falling entities - Slope Supports - Examples of these include retaining walls, rock bolts, and metal screens - Landslide Warning Systems - Tiltmeters are instruments used to detect movement along a slope - Some rock fences along railways in western North America are linked to signal systems - Rain gauges on slopes can identify when a precipitation threshold has been reached - Perception of the Landslide Hazard - The relative infrequency of large landslides tends to reduce awareness of this hazard - It is especially a concern where evidence of past events is not visible - People continue to build in areas prone to landslides - This requires adjustments to minimize deaths and property damage - Adjustments to the Landslide Hazard - It is crucial to safely cite critical facilities (hospitals, schools, power plants) away from landslide-prone areas; analyzing hazard maps and avoiding the purchase of a home in a hazardous area is the best way to reduce risk - Reducing water pressure through good drainage is the best corrective measure against landslide hazards since this will decrease the driving force Lecture 5 - October 16, 2023 - The Energy Balance - On earth, there is an equilibrium between incoming and outgoing radiation - Earth intercepts only a small portion of the Sun’s total radiation - It is this energy from the Sun that drives the hydrologic cycle and all the weather phenomena on Earth - If all the energy that is absorbed is eventually dissipated back to space, then the earth will not heat; however gases absorb energy leading to warming of the earth - The Atmosphere - It is composed of nitrogen (78%) and oxygen (21%) - The remaining 1% consists of water vapour, carbon dioxide, and other ‘trace’ gases - Water vapour in the atmosphere can lead to cloud development and the formation of precipitation; water vapour is the result of evaporation from bodies of water - Structure of the atmosphere - From highest to lowest: thermosphere, mesosphere, stratosphere, troposphere - Most clouds are confined to the troposphere - The ozone layer (25 km above the surface) protects us from the Sun’s harmful UV rays - It is found in the stratosphere - Clouds - Cloud names (dry weather, no precipitation) generally contain a prefix and a suffix

- Prefix describes the height of the cloud - High cloud: cirro- - Mid level cloud: alto- - Low cloud: strato- - Suffix describes the appearance - Puffy: -cumulus - Flat: -stratus - Clouds that produce precipitation contain “nimb” in their name - Cumulonimbus: a cloud that produces lightning, thunder, and heavy rain - Nimbostratus: a cloud that produces light to moderate precipitation - Fronts - A front is a boundary between two air masses - The name of the front describes the air behind it; fronts generally move west to east - At a cold front, dense cold air undercuts the warm air that is in front of it - Forces air upwards thus causing the formation of cumulonimbus clouds from cumulus clouds that gain vertical development from undercutting of warm air - Therefore only cold fronts cause thunderstorms - At a warm front, the less dense warm air (that would rise) gently overrides cold air - Thunderstorm - At any moment, there are approximately 2000 thunderstorms occurring on Earth - Thunderstorm development requires: - Water vapour - A large difference in temperature between air at the ground and air aloft - Rising air (or a lifting mechanism, e.g. a cold front) - Thunderstorm development - They develop in three stages: cumulus, mature, dissipative - Most pass through all three stages within one hour - Hail - Hail can only form in a cumulonimbus cloud - Updrafts in the cloud repeatedly force a water droplet upward - The droplet develops a ring of ice around it each time it enters the cold part of the cloud - There are aspects of the cloud that reach below freezing temperatures - The number of rings on a hailstone indicates how many cycles of freezing- thawing that occurred before gravity finally dragged it down - The ball of ice eventually becomes heavy enough to fall to the ground - China (2002) - Hail the size of basketballs caused 25 deaths; biggest hail observed on earth - Lightning - A spark of electricity occuring in a cloud - Most lightning strikes are from cloud to cloud rather than cloud to ground - Lightning heats the air causing the air to expand thus creating a shockwave (thunder) - Sometimes the atmosphere refracts thunder, making it inaudible

- Causes of lightning - Requirement: A cumulonimbus cloud containing a region of opposite charges - The interaction of ice crystals, hailstones, and water droplets result in a separate distribution of charges in the cloud - Tornado - A rotating column of low pressure air touching the ground that forms within a supercell thunderstorm; a rotating column not touching the ground is referred to as a funnel cloud - Characteristics of Tornadoes - Most range between 300 and 500 metres wide and they travel from the southwest toward the northeast at an average speed of 50 km/h - Northeast movement because of the jetstreams in North America that carries it along - They tend to exist for less than 20 minutes with a defined life cycle - The most common season for tornadoes is Summer in Canada and Spring in the U.S. - Tornado Life Cycle - Organizational stage - Wind shear causes rotation to develop - Wind shear: a change in wind speed or wind direction over a distance - An updraft causes tilting of the rotating air column, the horizontal air column turns into a vertical air column, thus resembling a tornado - A funnel cloud protrudes from above - Dust and debris rotate beneath - Mature stage - Most severe damage occurs at this stage - Rope stage - The tornado stretches out and weakens to eventually dissipate - Classifying Tornadoes - Enhanced Fujita Scale: tornadoes are classified on a scale of EF0 to EF5 based on damage - EF5 tornadoes: complete devastation; wind speeds over 322 km/h (strongest on earth) - Less than 1% of tornadoes are classified as EF5; only one in Canadian history - Tornado Alleys - The United States experiences the most tornadoes on Earth - Canada experiences the second most - United States Tornado Alley: Kansas and Oklahoma - Canada Tornado Alley: Southwestern Ontario (509 area code) - Alleys exist because they are areas where air masses commonly collide - They are areas of relatively flat land, which allows for undisturbed air rotation - Canada’s Tornado Alley - Tornadoes in Ontario occur when a south westerly wind brings warm, moist air from the Gulf of Mexico; warm air streams interact with cooler lake breezes, triggering rotation - Notable Tornadoes

- April 3, 1974: Super Outbreak - On this day, 148 tornadoes touched down between Ontario and Alabama - Caused by only one cold front which interacted with many thunderclouds - The largest tornado outbreak in world history occurred in 2011 from April 25th to 28th - In the southeast U.S., 358 tornadoes touched down and 324 were killed - Overall, there were more deaths from tornadoes in 2011 than any other year since 1925 - In 2011, we had greater technology which meant more warnings, greater ability to detect and communicate these events, but still had a large number of deaths - Joplin Tornado - May 22, 2011: an EF5 tornado caused 162 deaths in Joplin, Missouri - This tornado was the costliest in U.S. history ($2.2 B) and the deadliest since 1947 - Goderich Tornado - In Goderich, killed 1 person and destroyed much of the town core on August 21, 2011 - It was the first EF3 tornado to touch down in Ontario in 15 years - The tornado was spotted over Lake Huron on RADAR and a warning was issued 12 minutes before it reached the town - Moore Tornado - On May 20, 2013, an EF4 tornado in Moore, Oklahoma caused 24 deaths - A tornado warning was issued for the area 16 minutes in advance - Advances in weather technology have greatly improved our warning systems - Cyclones - Tropical cyclones - These only form over warm water, usually at latitudes 5-30 degrees They include hurricanes and typhoons - They contain high winds, heavy rain, and storm surges - Extratropical cyclones - These form over land or water in temperate regions at latitudes 30-70 degrees - They are associated with fronts and are also called mid-latitude cyclones - They contain rain, snow, freezing rain, etc. - Tropical cyclone development - Tropical disturbance: a large low-pressure area with unsettled weather - Tropical depression: an unorganized area of thunderstorms - Tropical storm: an organized area of storms with winds of 65-119 km/h - Stage at which names are applied to the storm - Hurricane: a circle shaped low-pressure area with winds of at least 120 km/h - Tropical Cyclones - They are referred to by different names in different parts of the world - They require a water temperature of at least 26 ℃ - Currents in South America create cooler water temperatures and thus no formation - Components of Hurricanes - Eye: a region in the center with light winds and clear to partly cloudy skies; sinking air

- Eyewall: a ring of intense thunderstorms that whirl directly around the eye - Spiral Rain Bands: rings of tall clouds and heavy rain that exist throughout the hurricane - Naming Atlantic Ocean Hurricanes - Names were first assigned to hurricanes in 1953 - Alternating male and female names are used in alphabetical order (5 letters skipped) - The name is retired if the hurricane produced notable damage; ex: Andrew, Katrina - Names were exhausted for the first time in 2005 when 27 hurricanes occurred and for the second time in 2020; when the list of names is exhausted, the remaining storms are named after the letters of the Greek alphabet (in order) - Hurricane movement - Hurricanes typically travel very slowly; less than 20 km/h - Because wind in a hurricane rotates counterclockwise, wind speed varies throughout the hurricane; the highest surge winds harmonize with the hurricanes movement whereas the weakest winds will be counteracted by the hurricane movement - Storm Surge - It is the most devastating effect of hurricanes - Storm surges result from powerful winds that create a rapid rise in sea level - Hurricane Andrew 1992: 23 ft storm surges occurred in Florida, inundating buildings - Classifying Hurricanes - Hurricanes are classified by the Saffir-Simpson Scale; category 1 to 5 - The classification is based on wind speed - Regions at Risk - In North America, the Atlantic coast and the Gulf of Mexico coast are at the highest risk - The official hurricane season ranges from June 1st to November 30th - Many hurricanes occur in August and early September because this is when the water is warmest due to the slow rate in which water temperatures rise in large bodies of water - Hurricane Katrina - Parts of New Orleans are actually located beneath sea-level, thus when the storm surge hit, the levees that were in place were ineffective and eventually toppled, causing floods - Hurricanes in Canada - Hurricane Fiona: September 24, 2022 - Two deaths and was a category 2 hurricane when it made landfall in Nova Scotia - Hurricane Hazel: October 15, 1954 - It killed 81 people when intense flash floods in Toronto swept away homes; no other natural disaster has caused that many deaths in Canada to this day - Flooding of the Humber River caused the most damage - Fog - It is a cloud with its base at the Earth’s surface - It occurs at night when the air cools to the dew point - The point at which water vapour condenses into droplets - Fog can also form when warm air moves over a cold body of water - Snowstorms as Hazards

- In the Great Lakes region, more deaths have been caused by snow storms than any other hazard; the worst natural disaster in Detroit (death toll) was a snowstorm in 2003 - The storm resulted in the deaths of 36 people from heart attacks while shovelling snow - When the temperature is close to 0, the snow becomes wetter and harder to move - Blizzards - They are intense winter storms with very specific conditions: - Winds of at least 40 km/h - Snow falling or blowing snow occurring - Visibility less than 400 m - All of these conditions must occur for at least 4 hours - Lake Effect Snow - Lake-effect snow is caused by cold air moving over relatively warm water - Snowbelts (regions affected by lake effect snow) are found downwind of the Great Lakes, where in the winter, the wind is often coming from the northwest - Heavy snow falls downwind of lakes (white regions on map) - Lake Effect Snow in Southern Ontario - London and Kitchener frequently receive lake effect snow from Lake Huron causing high annual snowfall; Windsor occasionally receives lake effect snow from Lake Michigan - Lake Effect Clouds - Southern Ontario frequently experiences lake effect clouds in Winter - Responsible for the cloudy weather experienced during warmer winters - Both lake effect clouds and lake effect snow diminish when ice appears on the lakes - Haboobs - A sandstorm that occurs in arid (little precipitation) and semi-arid regions - Downdrafts on the leading edge of a thunderstorm cause haboob formation - Dust Devils - A small spinning vortex of air formed over hot, dry land; no clouds are involved - As hot air rises, the wind direction may change due to an obstacle, this may result in a spinning column of air that is relatively harmless compared to a tornado - Ice Storms - These are mainly caused by freezing rain; weight of ice can pull down trees/power lines - Freezing rain is rain that freezes as soon as it lands on a surface; falls as normal rain - Warm fronts that override cold fronts will allow for temperatures to exist that permit rainfall (instead of snow), droplet freezes on impact due to the colder temperatures - Droughts - This is an extended period of unusually low precipitation - Droughts affect more people in North America than any other hazard - Droughts are linked to global weather patterns; are a normal part of the climate system - They cause water shortages that can lead to crop failure; in developing countries this may lead to malnutrition and famine - Temperature and Humans

- Wind Chill - Correction factor to an air temperature caused by the presence of wind making the air feel cooler than the temperature it suggests - Without wind, there is a protective layer of air that exists at similar temperatures to the temperature of our skin; blowing wind will carry this away - Humidex - Correction factor to an air temperature caused by high humidity making the air feel warmer than the temperature it suggests - Minimizing Severe Weather Hazards - Forecasting has improved dramatically with better technology - 3-day forecasts are very accurate, 7-day forecasts are pretty accurate - Weather satellites detect cloud cover, aid in forecasting hurricanes/mid-latitude cyclones - RADAR detects precipitation (both the type of precipitation and intensity) - Hazardous Weather - The most important job of a forecaster is to alert the public of potentially dangerous weather, where alerts are broken into three categories - Watch: an alert covering a wide area - Conditions favour the development of hazardous weather, but no reports - Ex: tornado watch if wind shears, winter storm watch if fronts approaching - Warning: an alert that usually covers smaller areas - It indicates the hazardous weather is currently occurring in the area - Ex: severe thunderstorm warning - Advisory - It is issued to alert the public of less hazardous weather conditions - Ex: dense fog advisory Reading 1 Questions 1. What is the definition of a microplastic? - Plastics that are broken into such small and fine pieces that they are hard to see 2. Even though the amount of plastic produced has increased exponentially in recent decades, what was the reason for why the amount of plastic in oceans and beaches doesn’t appear to be rising as fast? - Missing plastic is getting broken into pieces so small they’re hard to see; microplastics 3. What is more worrisome to scientists than eating fish that may have consumed microplastics? - There is little evidence that the edible flesh of fish that consumed microplastics actually contains microplastic fragments; the major concern surrounds the chemicals that were added to the plastics that could pass into the tissues of the fish, or the even smaller nanoplastic fragments 4. What is the largest market for plastics today? - Disposable packing in the growing economies of Asia where garbage collection systems may be underdeveloped or nonexistent 5. More than one quarter of the world’s plastic is produced in which country?

- Half of the world’s mismanaged plastic waste was generated by just five Asian countries: China, Indonesia, the Philippines, Vietnam, and Sri Lanka 6. How has the use of plastic saved wildlife in the past? - Plastics saved wildlife in the sense that it provided an alternative material to the scarce resources found on Earth; one prominent example would be elephant ivory where the introduction of plastics allowed for the production of billiard balls, piano keys, combs, etc. 7. How is the recycling shop in Manila that is operated by the Plastic Bank trying to improve the situation? - Plastic Bank of Vancouver pays a premium for bottles and hard plastic collected by waste pickers; it then sells that plastic at a higher price to multinationals, which market their recycled products as socially responsible 8. What is a sachet and how do they contribute to the issue? - Sachets are tear off packets that once held a single serving of shampoo, toothpaste, coffee, condiments, or other products and are sold by the millions to poor people who cannot afford to purchase more than one serving at a time, they are also non-recyclable 9. What have PepsiCo and Coca-Cola pledged to do by 2030? - Pledged to collect and recycle the equivalent of 100% of its packaging by 2030; they and others also pledged to convert to 100% reusable,recyclable, or compostable packaging by 2025 10. Explain the concept of a global fund and how it could help in tackling the problem. - Global fund is the concept of taxing a penny for every pound of plastic resin manufactured which would raise roughly six billion dollars a year that could be used to finance garbage collection systems in developing nations and help solve the issue with international/global efforts Reading 2 Questions 1. Millions of sea creatures died along the B.C. coast from the combination of low tide and an extreme heat wave. If they are unable to re-establish in the area, what are some implications of this? - If they are unable to re-establish, there will be shifts in the food chain, altered nutrient cycling, and the domination of invasive species as a result of the extinction of native species 2. What is a cascading hazard? - Cascading hazard occurs where one extreme event triggers another; for example an intense heatwave that then causes wildfires to break out in the area which causes the melting of glacier and snow and subsequent flooding and landslide events 3. What is the 2030 Nature Compact? - A pledge to conserve at least 30 percent of their land and water by 2030; three time based objectives, zero net loss of nature from 2020, net positive by 2030, full recovery by 2050 4. What is described as the conundrum around motivating people to action from a specific event? - While scientists record such events and duly incorporate them into future models, public and political attention moves on to the next disaster; weakness in the media’s representation of deadly temperatures as well as their connection to climate change 5. What was the faint hope provided in the report of the International Panel on Climate Change?

- Only immediate and drastic reductions in greenhouse gas emissions can prevent the worst effects of climate breakdown 6. What are the three highest profile examples of the interaction of climate change and biodiversity? - Impacts on polar wildlife such as seals, walruses, polar bears, and penguins - Displacement and death by wildfires - Warming ocean responsible for everything from the bleaching of coral reefs to the turbo charging of sea star wasting disease 7. What is the biohazard aspect associated with wildfires? - Microbes and fungal spores can survive in wildfire smoke and be passed to neighboring areas 8. When Simon Donner of UBC was asked if this was the new normal, how did he respond? - He answered that things were now changing so fast that he didn;t think there was ever going to be anything we could describe as normal again 9. Why was it suggested that policies for protected areas and species at risk are insufficient for reaching biodiversity goals? - “No matter what the percentage of protection, it really depends on what’s going on in the remaining percentage of unprotected areas; it is context dependent and relies on protecting areas that exist outside of protection boundaries and areas” 10. What has the government realized about implementing protections? - That different strategies in different places will lead to the best outcomes and that solutions need to be sought on as many levels as possible Lecture 6 - November 6, 2023 - Earthquakes - They result from the rupture of rocks along a fault - Energy from an earthquake is released in the form of seismic waves - Mapped according to the epicentre; the focus is located directly below the epicentre - They are measured by seismographs and compared by magnitude - Earthquake magnitude - The magnitude of an earthquake is expressed as a number to one decimal place - This type of measurement was first developed by seismologist Charles Richter in 1935 - The Richter Scale was a measure of the strength of a wave 100 km from the epicentre - Since then, more accurate methods have been developed and the Richter Scale is no longer in use; although the media may refer to the use of the Richter Scale still… - The Moment Magnitude Scale - Today, earthquakes are compared using the Moment Magnitude scale (M) - The scale is determined by: - The area of rock ruptured along a fault - The distance of movement along the fault - The elasticity of the rock at the focus - Like the Richter Scale, the Moment Magnitude is a logarithmic scale - Ex: an M7 earthquake represents 10 times the strength of an M6 earthquake

- Ex: an M8 earthquake is 1000 times the strength of an M5 earthquake - Magnitude and Frequency of Earthquakes - There is no official upper limit on the Moment Magnitude Scale - The strongest earthquake ever recorded on the scale is M9.5 in Chile in 1960 - In Canada, it is M8.1 in B.C. in 1949 - There are only a few M9+ earthquakes each century - The Modified Mercalli Intensity Scale - This is a qualitative scale based on damage to property and the effect of an earthquake on people; descriptive statements to measure the relative intensity of an earthquake - Earthquake Processes - Earthquakes are most common at or near plate boundaries - Motion at plate boundaries is not smooth or constant - Friction along plate boundaries exert a force (stress) on the rocks, exerting strain, pressure, or deformation on the other plate - When stress exceeds the strengths of the rocks, there is sudden movement along a fault - The rupture starts at the focus and propagates in all directions in the form of seismic waves; thus faults are considered seismic sources - Identifying faults is necessary to evaluate the risk of an earthquake in an area - Not all faults are found at the Earth’s surface - Blind faults are located below the surface - Fault Types - There are two basic types of geologic faults; they are distinguished by the direction of the displacement of rock: - Strike-slip fault: displacements are horizontal - Dip-slip faults: displacements are vertical - Strike-slip Faults - The San Andreas Fault is the best example of this type of fault - Dip-slip Faults - There are three categories: - Reverse faults, thrust faults, and normal faults - They are comprised of two inclined walls, as defined by miners: - Foot-wall: where miners placed their feet - Hanging-wall: where miners placed their lanterns - Reverse Fault → normally found along convergent plate boundary - The hanging wall has moved up relative to the footwall and is inclined at an angle above 45 degrees - Thrust Fault - There are like reverse faults except the angle is 45 degrees or less - Normal Fault → normally found along divergent plate boundaries - The hanging wall has moved down relative to the footwall - Fault Activity - In terms of activity, faults can fall into one of three categories:

- Active: movement during the past 11,600 years - Potentially active: movement during the past 2.6 million years - Inactive: no movement during the past 2.6 million years - Although in the past, some inactive faults have resulted in earthquakes… - Tectonic Creep - The extremely slow movement of rock along a fracture caused by stress - It is also referred to as a fault creep - This can damage roads and building foundations (movement of few cm per decade) - Along these faults, periodic sudden displacements producing earthquakes can occur - Seismic Waves - Some seismic waves generated by fault rupture travel within the body of the Earth (body waves) and others travel along the surface (surface waves) - Body waves - These include P waves and S waves and occur underground within the Earth - P waves: also called primary or compressional waves; measured w/ seismographs - They move relatively fast with a push-pull motion and can travel through solids (in the crust) or liquids (in the mantle) - S waves: also called secondary or shear waves - They move relatively slow, in an up-and-down motion and can only travel through solids (in the crust), cannot travel through liquids - Surface Waves - Seismic waves that form when P waves and S waves reach Earth’s surface and then move along with it; these are the waves that cause surface damage - These waves more more slowly than body waves - Surface waves are responsible for damage near the epicentre - Earthquake Shaking - Factors that determine the shaking that people experience during an earthquake: - Magnitude - Distance from the epicentre - Focus depth - Direction of rupture - Local soil and rock type - Local engineering and construction practices - Seismographs record the arrival of waves to a recording station - Because P waves travel faster than S waves, they appear first on a seismogram - Earthquake shaking decreases with distance from the epicentre - Distance to the Epicentre - The difference between the arrival times of the P waves and S waves at different locations determine the distance to the epicentre - The distance to the epicentre is calculated at three different seismic stations - A circle with radius equal to that distance is drawn around the station

- Locating an Earthquake - The epicentre is located where the circles intersect; this is called triangulation - Focus Depth - Seismic waves become less intense as they spread outward toward the surface - Therefore, the greater the focus depth, the less intense the shaking at the surface - Direction of Rupture - Earthquake energy is more focused along the geographic direction of rupture - This is known as directivity and contributes to increased shaking - Radiated waves are sometimes stronger along the direction of the fault - Local Soil and Rock Types - The local geology influences the amount of ground motion - Dense homogenous crust can transmit earthquake energy quickly and easily - Seismic energy slows down in areas with heterogeneous, folded, faulted, crusts - Implication: earthquakes in eastern North America are felt over larger areas than those in western North America; the underlying bedrock is more homogenous in the the East - Amplification - Definition: an increase in ground motion during an earthquake - P and S waves slow down as they travel through alluvial sand, gravel, clay, soil, etc. - Alluvial: deposition of sediments by water during storms, rain, waves - As these waves slow, some of their energy is transferred to surface waves, thus intensifying the ground motion in these areas - Amplification has historically enhanced damage in San Francisco area earthquakes where the underlying soil is responsible for the increased damage - Shake Maps - The combination of all these effects resulted in widespread variation of the shaking felt in the vicinity of an earthquake - Therefore, two earthquakes that have the same magnitude can have very different impacts based on the constitution of the region and intrinsic properties of the quake - The Earthquake Cycle - A hypothesis that explains successive earthquakes on a fault over time - It is based on the idea that strain drops abruptly after an earthquake and then slowly accumulates until the next earthquake event - As stress continues to increase, the deformed rocks will eventually rupture - A typical cycle has several stages: - An inactive period - A period where strain produces minor earthquakes - A period of foreshocks prior to a major release of stress - This stage does not always occur - Foreshock: a small to moderate (M4-5) earthquake that occurs shortly before and in the same general area as the mainshock - A period where the mainshock occurs allowing the fault to release built up stress

- Mainshock: the largest earthquake in a series of associated earthquakes - A period of aftershocks; small to moderate (M4-5) earthquakes that always occur shortly after an in the same general area as the mainshock - The time between each stage varies - Aftershocks - Generally, the number of aftershocks that occur on a given day after a mainshock can be forecasted by a formula: - Aftershocks = aftershocks on a first day after mainshock / given day - Example: if 200 aftershocks occurred on the first day after the mainshock, how many aftershocks are likely to occur on the 7th day after the aftershock - 200/7 = - Geographic Regions at Risk from Earthquakes - Earthquakes are not randomly distributed - Most earthquakes occur along plate boundaries: - Pacific Ring of Fire, Himalaya Mountains, Middle East - North american cities at high risk of earthquakes: Anchorage, Vancouver, Victoria, Seattle, Portland, San Francisco, Los Angeles, Mexico City - However, not all regions at risk of earthquakes are near plate boundaries - Plate Boundary Earthquakes - Earthquakes that occur on faults which specifically separate plates - There are three types: - Strike-slip earthquakes → horizontal movement - Thrust earthquakes → vertical movement - Normal fault earthquakes - Strike-slip Earthquakes - Occur along transform faults where plates slide horizontally past one another - They are common in California along the San Andreas Fault - The best-known strike-slip earthquake is the Loma Prieta earthquake that disrupted the 1989 World Series in Oakland, California - Thrust Earthquakes - These earthquakes occur on faults that separate converging plates - They are also called subduction earthquakes - They are common off the coast of B.C., Washington, and Oregon - These earthquakes are the strongest on Earth (some are larger than M9) and can produce tsunamis - Normal Fault Earthquakes - These earthquakes occur on faults associated with divergent plate boundaries - They are common along the Mid-Atlantic Ridge - Most are located under oceans and are generally smaller than M6 - Intraplate Earthquakes - An earthquake on a fault in the interior of a continent, far from a plate boundary - These earthquakes are typically not as strong as plate boundary earthquakes

- However, damage could be considerable due to lack of preparedness - Because of dense continental bedrock these earthquakes are felt over large areas - There are two relatively active intraplate zones in North America: - Central Mississippi River Valley - St. Lawrence River Valley - The New Madrid earthquakes in Missouri (1811-1812) were over M7.5 and felt across the entire continent as a result of the continental bedrock - The recurrence interval in this area is likely several hundred years - Recurrence interval: the time between successive events - Effects of Earthquakes - Several effects related to earthquakes contribute to deaths and property destruction - Primary effects: ground shaking, surface rupture - Secondary effects: liquefaction, land-level change, landslides, fires, tsunamis - Surface Rupture - Displacement along faults causes cracks in the surface - During strong earthquakes, fault scarps (a linear escarpment at the Earth’s surface formed by movement along a fault during an earthquake) can be produced that extend for hundreds of kilometres - Ruptures can uproot trees, collapse buildings, and destroy bridges, tunnels, pipelines - Liquefaction - The transformation of water-saturated sediment from solid to liquid during an earthquake; it occurs when water pressure becomes high enough to suspend particles of sediment within the soil, the connections between sediment particles is lost - Once the pressure decreases, the sediment compacts and regains its strength - Watery sand and silt may flow upward along fractures in the overlying rock, creating small mounds that can accumulate and eventually cause extensive damage - Landslides - Ground shaking can cause rock and sediment to move downslope - A single earthquake in a mountainous area can cause thousands of landslides - Fires - Ground shaking and rupture can start fires by severing power and gas lines - Appliances may topple over causing gas leaks that may ignite - Approximately 80% of the damage during the 1906 San Francisco earthquake was caused by fire and the inability to bring fire fighting equipment in due to rubble - Natural Service Functions of Earthquakes (of Faults) - Faults provide pathways for the downward flow of surface water - They can also channel groundwater to surface discharge points (springs) - New mineral resources can be exposed; some are preferentially deposited in faults - Scenic landscapes (hills, valleys) develop in fault zones over millions of years - Earthquakes caused by Human Activity - Several human activities are known to trigger small to moderate earthquakes

- The weight from water reservoirs produced by dams can create new faults - Injecting liquid waste (eg. from Nuclear Power Plants) deep in the Earth can increase pressure and cause slippage along fractures - Testing nuclear weapons leads to explosions that may increase strain in an area - Fracking and oil drilling that leads to ground shaking events - Minimising the Earthquake Hazard - Earthquakes cause death and destruction because they often occur with little warning - At present, we can forecast the likelihood that an earthquake will occur in an area, but not precisely when it will occur - The Geological Surveys of Canada and the U.S. have developed programs to reduce the hazard from earthquakes - Earthquake Hazard Reduction Programs - The programs have five goals: - Improve national seismograph networks - Develop awareness of earthquake sources (ie. find faults) - Determine earthquake potential - Predict effects of earthquakes on buildings (eg. earthquake simulations) - Communicate research to educate the public - Planning for Earthquakes - The Denali earthquake in Alaska in 2002 demonstrated the value of planning - Where the Trans-Alaska oil pipeline crossed the Denali fault, its construction was altered to withstand a large earthquake where the pipes in that region were modified to sway along with the earthquake thus minimising damage to the entire pipeline - Estimating Seismic Risk - Hazard maps identify areas of risk associated with earthquake effects and they include areas prone to liquefaction, zones of potential ground rupture, and historic epicentres - Precursors to Earthquakes - If higher accuracy forecasts are possible, they will most likely be based on precursors: 1. The pattern and frequency of smaller ruptures - Based on foreshocks and microearthquakes (M2 or less) 2. Land-level change - Uplift or subsidence may precede earthquakes - GPS can recognize small changes in elevation 3. Seismic gaps along faults - Areas along a fault that have not seen recent earthquakes may be more likely to experience one than areas that have recent earthquakes 4. Physical and Chemical changes - Changes in groundwater level and/or chemistry may occur if rocks expand prior to an earthquake - Earthquake Forecasting - There have been modest incidences of successfully forecasting earthquakes - All forecasts must be scientifically reviewed before they are released

- Research projects along the San Andreas fault aim to improve our understanding - Current warning systems provide 15 to 30 seconds of warning and only warn of a major earthquake that has already occurred - Perception of the Earthquake Hazard - Survivors of strong earthquakes often report traumatic stress - Typically, one community’s experience with an earthquake has not stimulated other communities to enhance their preparedness (ie. react but no proactive response) - Earthquakes have exposed shoddy construction practices (improper building codes) - Community Adjustments to the Earthquake Hazard - It is not possible to prevent people from living in earthquake-prone areas, therefore several steps are necessary to minimise seismic risk: - Critical facilities should be located as safely as possible - Buildings must be designed to withstand vibrations (retrofitting if needed) - Education is a component of preparedness (workshops, training sessions, drills) - Earthquake insurance should be made available in high-risk areas - Personal Adjustments to the Earthquake Hazard - Most earthquake casualties result from building collapse and falling objects - During an earthquake, it is best to stay away from windows and tall furniture - The safest locations are under desks or tables Lecture 7 - November 13, 2023 - Volcanoes - Most volcanoes are located near plate boundaries - Approximately 65% of all volcanoes are found along the “Ring of Fire” surrounding the Pacific Ocean - Subduction zones and mid-ocean ridges allow molten rock to reach the surface - Types of Molten Rock - Magma: it is found deep within the crust and upper mantle - Lava: it is found flowing from an erupting volcano - Essentially, lava is magma on the Earth’s surface - Magma - The most abundant elements in magma are silicon and oxygen - When it is combined it is referred to as silica - Volcanic rocks are named based on the amount of silica present - Types of rock: basalt, andesite, dacite, rhyolite (from low to high silica content) - Viscosity - Magma also contains small amounts of gases (water vapour, carbon and sulphur dioxide) - Volcanoes have different shapes based on the chemistry and viscosity of their magma - Viscosity: the resistance to flow

- Magma viscosity is determined by silica content and temperature - Magma - Magma with high silica content: cooler, more viscous, more gases - Magma with low silica content: hotter, less viscous, fewer gases - As magma approaches the surface, the pressure lowers which allows gases to bubble up and escape - Volcanoes with high silica magma produce the most explosive explosive eruptions - Rhyolitic and dacitic magmas produce explosive eruptions - Volcanoes with low silica magma have higher temperatures and involves magma flow - Basaltic and andesitic magmas produce nonexplosive eruptions with flowing lava - Types of Volcanoes - Volcanoes are classified into 4 types based on shape, appearance, and eruption style: - Shield - Composite - Volcanic dome - Cinder cone - Shield Volcanoes - These are the largest volcanoes on Earth and are shaped as broad arcs built from lava - They are associated with basaltic magma - Eruption consist of well-flowing magma - Some eruptions can contain tephra (fragmented material blown out during an eruption) - Accumulations of tephra are referred to as pyroclastic deposits - If compacted together, these deposits are called pyroclastic rock - These volcanoes are common in Hawaii, Iceland, and around the Indian Ocean - Composite Volcanoes - These volcanoes are very tall, cone-shaped and are built from a combination of lava flows and pyroclastic deposits - They are also called stratovolcanoes; this term comes from the stratified layers of lava and deposits within the volcanoes themselves → produces the cone-shape - Eruptions are more dangerous and explosive but less frequent than shield volcanoes - These volcanoes are common along the west coast from Alaska to Northern California - Mt. Rainier, Mt. St. Helens (both in Washington State) and Mt. Adams (Oregon) are the most well-known composite volcanoes in North America - Volcanic Domes - These volcanoes contain highly viscous rhyolite magma - They are steep-sided mounds that form around vents - Cinder Cone Volcanoes - These are relatively small volcanoes composed of small forms of tephra - They are round to oval-shaped and typically contain a crater at the top - These volcanoes are found in Mexico - Maars

- A circular volcanic crater produced by an explosion and filled with water - They are caused by groundwater encountering magma, creating the explosion - Magma contains chemicals, and groundwater contains chemicals, that if mixed can potentially cause an explosion - Maars derives from the Latin mare meaning sea and resembles a large lake - Ice-contact Volcanoes - Some volcanoes erupt beneath or alongside glaciers - These eruptions melt huge quantities of ice producing floods known as jokulhlaups - When lava contacts glaciers, it quickly cools to form pyroclastic rock - Ice-contact volcanoes are found in Iceland and in British Columbia - Evidence of the Mt. Garibaldi eruption 12,000 years ago in British Columbia is preserved in currently exposed rock → formation of canyon wall on a cliff face - Volcanic Features - Crater: a depression formed by the explosion of a volcano top; up to 2 km in diameter - Volcanic vent: an opening on the surface through which lava and pyroclastic debris erupt - Most vents are circular, but some are elongated cracks called fissures - Caldera: a circular to oval depression formed during the inward collapse of a volcano - They can be up to 25 km in diameter - Eruptions that form calderas are the largest and most deadly eruptions on Earth - Formation of Calderas - Calderas are formed by the collapse of a magma chamber below a composite volcano during an explosive eruption → magma chamber and veins are emptied thus there is nothing to support the weight of the rock, causing it to collapse in on itself - Hot Springs and Geysers - Heated groundwater can discharge at the surface as a hot spring - Groundwater that boils in an underground chamber to periodically produce a release of steam or water is called a geyser - There are approx 1000 geysers on Earth and nearly half are in Yellowstone National Park - Old Faithful - This is the most famous geyser in the world - It erupts to a height up to 50m with eruptions lasting for 2-3 minutes - The average interval between eruptions is 70 minutes - Super Eruptions - These are the products of supervolcanoes and are extremely rare events - They occur when a large volume of magma rises to shallow depths in the continent crust (relatively thick) over a hot spot location - The magma is originally unable to breath through the crust; pressure continues to build until the crust can no longer contain it where the explosion will then occur - Yellowstone super eruption 640,000 years ago covered a massive amount of land w/ ash - Yellowstone National Park and Yellowstone Supervolcano

- Yellowstone National Park sits on a massive caldera created from the last eruption of the Yellowstone Supervolcano 640,000 years ago - The area is located over a continental hot spot - Super eruptions occurred there 2.2 million years ago, 1.3 Mya, and 640,000 years ago - Earthquakes in the park are monitored continuously - A super eruption could last for weeks and spread ash over half of the U.S.; an amount of ash that would be over 1000 times that released by Mt. St. Helens - Millions of people would die from ash suffocation and the U.S. agriculture economy would be destroyed from a supervolcano eruption - Along with the hundreds of geysers, the park is home to many species of wildfire - Volcanoes in Canada - They are found only in British Columbia and southern Yukon - Mt. Baker in Washington State provides the greatest actual risk to Canada - Mt. Baker - An eruption of Mt. Baker would eject large amounts of ash over a densely populated part of British Columbia leading to air pollution to humans and wildlife - It would also cause landslides and melt glaciers thus causing floods and lahars - Effects of Volcanoes - On average, 50 to 60 volcanoes erupt each year - Over the past two centuries, more than 100,000 people have been killed by eruptions - The reason for the lower amounts of death (compared to other hazards like tsunamis) are due to the smaller amounts of people who live in areas where volcanoes are hazards - Climatic Effects - Powerful eruptions can impact global climate - Ash and gases reflect solar radiation causing a cooling of the global temperature - Mt. Tambora (1815, Indonesia) 1816 is known worldwide as the year without a summer - Mt. Pinatubo (1991, Philippines) 1992 one of the coolest years in the 20th century - Lava Flows - Occur when magma flows out of a central crater or a fissure along the side of a volcano - Pahoehoe basaltic lava: low viscosity (a few km per hour), high temperature - When hardened, it has a smooth texture as a result of fully melted rocks - Aa basaltic lava: high viscosity (a few metres per day), lower temperatures - When hardened, it has a blocky texture as a result of unmelted rocks - Lateral Blast - Eruption directed away from a volcano where materials are blown parallel to the surface - Example: a lateral blast from Mt. St. Helens flattened forests for over 20 kilometres - Pyroclastic Flow - An avalanche of ash, gas, and rock fragments that travels down the slopes of a volcano during an explosive eruption - Speeds can reach 150 km/h and the flow can travel up to 30 km from the source

- More people have been killed by pyroclastic flows than any other volcanic phenomenon - Ash Fall - Particles of ash can be carried downwind hundreds of kilometres from an eruption site - Hazards of ash fall: - Destroys vegetation - Contaminates surface water - Health impacts to people and animals when inhaled - Causes aircraft engine failure - Poisonous Gases - Volcanoes emit numerous gases at high quantities - Sulphur dioxide can burn holes in leaves and lead to the formation of acid precipitation - A type of smog known as a vog can be produced - This may induce asthma attacks and respiratory problem - High amounts of carbon dioxide released at once can kill animals and vegetation - Sector Collapse - The flank of a volcano can collapse at any time - As magma travels up an inner channel, the volcano can form a bulge where its slopes have become over-steepened, leading to its eventual collapse - This can cause the formation of a tsunami if the land falls onto a body of water - Lahar - A large amount of material that has become saturated with water and moves downslope - Lahar is an Indonesian word - Lahars are also referred to as mudflows - Knowledge of local topography and the history of past events can aid in determining the recurrence intervals of lahars - Mt. St. Helens - Before its eruption, the volcano had been dormant for over 120 years - In March 1980, small explosions occurred due to groundwater contacting magma - A bulge began growing on the flank of the mountain - On May 18, 1980, a M5.1 earthquake caused the bulge to break off and fall downslope - A lateral blast occurred from the area of the former bulge and the entire north slope was destroyed as a result of the explosive eruption - Ash was ejected from the central crater, reached heights of 19km where the jetstream then allowed for this cloud of ash to travel around the world - It killed 57 people, mainly from pyroclastic flows - The eruption left behind a barren landscape that is slowly reforesting naturally - Natural Service Functions - Ancient volcanoes provided the gases that now form the atmosphere and sustain life - Internal heat from volcanoes can produce renewable geothermal energy - Volcanic landscapes attract tourism and recreation - Eruptions have created new land (Hawaii, Iceland)

- Minimizing the Volcanic Hazard - An eruption forecast is a statement containing the probability that a volcano will erupt within a given timespan; forecasts are based on information provided by: 1. Monitoring seismic activity - Shallow earthquakes can precede eruptions - Short warning times from this information are a concern 2. Thermal and hydrologic monitoring - An accumulation of magma changes properties of the rock and soil - Increased heat may melt snow or glaciers above 3. Land surface monitoring - Checking for the growth of bulges, swellings, and opening of cracks 4. Monitoring volcanic gas emissions - Increases in carbon dioxide or sulphur dioxide may indicate magma is moving toward the surface 5. Analyzing the local geologic history - Mapping of volcanic rocks - Dating of pyroclastic deposits Mount St. Helens Documentary 1. What is the term for the large area of devastation directly below the crater within the blowdown zone? Just beyond this area, what was the impact to the bed of Spirit Lake? - Pumice plane is the area of devastation located directly below the crater - Spirit Lake had its bed lifted more than 200 feet by the landslide; its surface covered by dead trees, aquatic life all dead, and black polluted water with hot springs emerging 2. What plant were the scientists surprised to find? How was it able to grow in such an inhospitable area? - Prairie Lupine was able to grow due to its special root structure that is able to produce its own nutrients; bacteria within the roots of the plant have symbiotic relationship 3. How did the bacteria in Spirit Lake make life impossible there? Why was the discovery of phytoplankton in the lake so important? - May 1980 explosion destroyed the lake; bacteria rapidly consumed the oxygen in the lake, making life impossible for air breathing organisms (fish, amphibians, insects) - Three years after the eruption, phytoplankton was found which is important because they convert sunlight into oxygen; the basic building blocks of aquatic life - Small aquatic plants also serve as a food source for rebuilding aquatic life 4. Why was the volcanic activity in 2005 different from that of the 1980 explosive eruption? - 2005 lava spines pushed through the crater floor only to collapse after it emerges - The particular seismic activity recorded during this period was the seismic signature of these volcanic spines emerging from the surface of the earth; drumbeat signature

- 1980 had an explosive eruption and also oozing liquid lava (1983: dome building phase) whereas 2005 was solid lava spines; composition of these volcanic spines showed that explosive lava contained a lot of gas bubbles (water in magma that creates bubbles that further pressurise the magma), lava of 2005 volcanic spines is gas-poor, there is just enough gas to slowly push these spines out of the surface → 2007 drumbeat disappears 5. What is the take home message from the decades of ecological work on Mt. St. Helens? - There will be another eruption on Mt. St. Helens; history has shown that it can sleep for 1000 years between eruptions but there have been instances of three year dormancies - Nature is very resilient; even though scientists didn’t expect nature to bounce back within three years of the 1980 explosion, the “eruption” of nature re-established life Lecture 8 - November 20, 2023 - Technological Hazards - These hazards have a wide and varied interpretation - They can vary from a single toxic gas leak to an entire industry (eg. nuclear energy) - Other examples include exposure to hazardous materials, chemical spills, and infrastructure failure - Hybrid disasters may fit into this category; combination of hazards - Ex: an earthquake that causes an oil spill from a pipeline - Technological disasters involving the environment are included in this category as well: - Ex: the sinking of the Titanic and explosion of the Challenger space shuttle - Vulnerability to Technological Hazards a - Typically, the death tolls from technological hazards are relatively low - Vulnerability is greatest to those involved in specific industries or transportation systems - Workers in resource industries in hinterlands are at higher risk (eg. miners) - Hinterland: rural, sparsely populated landscapes - Categories of Technological Hazards - Widespread: long term (hazards that lead to cumulative effects) - Rare events: airplane crashes, mine collapses, shipwrecks - Relatively common: automobile accidents, poisons - Cumulative Effects - These are conditions that worsen slowly over time as exposure to a concentration increases and eventually the concentration reaches a threshold critical to human health - Hazards with cumulative effects include exposure to radiation, toxic chemicals, acid precipitation, and groundwater contamination - Calculating Risk - infrastructure: risk is defined as the probability of failure during its lifetime - Transportation: probability of death or injury per km travelled - Industry: probability of death or injury per person per number of hours exposed - Radon

- The primary source of radon gas is from the natural decay of uranium in rock and soil - When radon is inhaled it decays to polonium, lodges in the lungs and damages tissues - It is the 2nd leading cause of lung cancer in North America - Radon becomes a hazard when it is released into our living space - It is difficult to detect because the gas is odourless, colourless, tasteless - Detectors are commercially available in geographic areas where it is of greater concern - The gas can move quickly through unsaturated soil and can seep into homes - Basements are at higher risk especially in winter due to reduced air circulation - Genetically Modified Organisms - These are organisms that have had changes made to their DNA by the transfer of genes - The most common crops that are genetically modified are corn, soybeans, canola, wheat - Crops are modified to increase yields - Some crops have been genetically engineered to have greater resistances to: - Extreme changes in temperature or precipitation; acidic soil - Herbicides and pesticides, pests - Examples of feats in genetic modification: - Chickens that lay low-cholesterol eggs - Tomatoes that can reduce the risk of cancer - Bananas and potatoes to treat some viral diseases that are common in developing countries - Rice that contains more vitamin A to improve vision acuity - Bacteria that can quickly clean up oil and toxic spills - Citrus trees producing fruit in their first year whereas it would normally take around six years for the production of fruit - How safe are genetically modified foods? - Scientists believe that the benefits outweigh the potential risks but most support more research studies into the matter - The UN Food and Agriculture Organization believes that genetically modified crops have great benefits especially in developing countries - Radiation - The impact of radiation on people can be direct (effects are evident within days of exposure) or delayed and chronic (leukaemia, cancer) - The impact could also be indirect in the form of genetic effects - Ex: a person may not experience any effects but may pass them on to their children in the form of chromosomal changes or birth defects - Potential Sources of Radiation - Mining of Uranium - In Canada, uranium is mined in Northern Saskatchewan and Northern Ontario - Mines produce wastes known as tailings that can be a radioactive hazard - Production of Electricity and Energy - Uranium is used in nuclear power plants - Nuclear Power Plants

- Most nuclear plants in North America are in the eastern half of the continent - They must be near sources of coolant (rivers or lakes; large bodies of water) - They must be located near a market for electricity (eastern NA is much more populated) - Nuclear is considered a clean source of energy because it does not emit the greenhouse gases that cause climate change - Nuclear Accidents - Meltdown: informal term for an accident that results in damage from overheating - It occurs when the heat generated by a nuclear plant exceeds the heat removed by its cooling systems - Fuel rods turn to liquid and the walls of the plant could melt from the extreme heat - The hot liquid could melt through the bottom of the plant and seep into the soil - Three Mile Island Nuclear Accident - This is the worst nuclear disaster in U.S. history; occurring on March 28, 1979 - One of the two power plants on Three Mile Island in Central Pennsylvania experienced a partial meltdown - It was caused by a failure of a valve that controlled cool water entering the plant - No direct injuries; minor amounts of radiation were released and the plant closed - Chernobyl Nuclear Accident - This is the worst nuclear disaster in world history; April 26, 1986 - Result of a flawed design, operator error, and disregard of safety regulations - An explosion at the plant caused the immediate deaths of three workers - Within one year, 28 more workers died from extreme radiation exposure - Over the following two decades, thousands of people developed thyroid cancer attributed to radiation exposure from the Chernobyl disaster - Nuclear Energy - The combined concern over the Three Mile Island and Chernobyl disasters slowed global nuclear development for a time, however, concern over greenhouse gas emissions has created a high demand for cleaner sources of energy; wind, hydro, solar… nuclear - The last remaining coal power plant in Ontario closed in 2014 - The province has invested in refurbishing existing nuclear power plants and is planning to build new ones as well - Titanic Shipwreck - The Titanic was a passenger ocean liner that struck an iceberg and sank on its maiden voyage on April 15, 1912 - The ship left Southampton, England on April 10th and was bound for New York City with 2224 passengers - The ship was designed using advanced technology and was believed to be unsinkable - Death toll was 1517; the high number was due to the lack of lifeboats for all passengers - The wreckage was found by SONAR in 1985 at a depth of 3.8 km - Chronology of the Titanic Shipwreck - Lookout on the ship spotted an iceberg in their path at 11:40 PM, alerting the captain

- The ship struck the iceberg 37 seconds later; 18 lifeboats were launched - Titanic sank at 2:20 AM - The Carpathia arrived at 4:10 AM and picked up survivors from the lifeboats - Oil Spills - Oil spills most commonly occur in water but also occur on land due to pipeline bursts - The environmental impact can be devastating and the cleanup takes months to years - Oil penetrates bird feathers and mammal fur reducing the ability to insulate - Birds and animals are left vulnerable to temperature changes and become less buoyant in water due to the additional weight of the oil - Exxon Valdez Oil Spill - Oil tanker ship striking a rocky reef off the south coast of Alaska on March 24, 1989 - The region is an important habitat for salmon, seals, sea otters, killer whales, seabirds - There were 75 million litres of oil spilled; remote location made recovery efforts difficult - It remained the worst oil spill in North American history until the Deepwater Horizon - Deepwater Horizon Oil Spill - The spill was caused by an oil rig that exploded in the Gulf of Mexico on April 20, 2010 - Explosion killed 11 workers, it was caused by methane rising upward through a drill pipe - Approximately 11 million litres of oil leaked from the well every day for months - After several failed attempts, the well was finally capped with cement on Sept 19, 2010 - Extensive damage to wetlands and beaches along the U.S. Gulf of Mexico coastline - The tourism industry faced severe economic loss during the summer of 2010 - The U.S. federal investigative report ultimately blamed B.P oil company for the disaster: - Made a series of cost-cutting choices on maintenance - Did not have a proper system in place to ensure safety - Groundwater - Groundwater is water that is found within the cracks, space, and pores in soil, sand, rock - Permeability comes from small connected spaces that allow water to flow through - Groundwater Contamination - Many cities and towns obtain drinking water from groundwater; contamination = risks - In 2000, water contaminated with E. coli bacteria killed 7 people in Walkerton, Ontario - Bacteria came from fertilizer manure that had leached into a well during a heavy rainfall - Infrastructure Failure - An example of infrastructure in North America occurred in Minneapolis in 2007 - A highway bridge over the Mississippi River collapsed during evening rush hour killing 13 - Minneapolis Bridge Collapse - Cause was deemed to be excessive weight from vehicles and construction equipment - The bridge supports were not of proper thickness and an extra 2 inches of concrete that was added to the roadway also contributed to the collapse - Tacoma Narrows Bridge Collapse - In 1940, high winds caused the collapse of a suspension bridge in Tacoma, Washington - There were no human casualties from the collapse due to ample warning time - The design of the bridge did not provide any open trusses for wind to pass through

- The incident serves as a good case study for engineering and architecture students - Space Shuttle Explosions - There have been two major space shuttle disasters: Challenger and Columbia - The Challenger Shuttle Explosion - The Challenger exploded 73 seconds into its flight on January 28, 1986 - All seven crew members were killed as the space shuttle disintegrated - Remains were scattered over the Atlantic Ocean - The cause was associated with a rubber O-ring seal that failed to seal a joint leading to the release of hot gas, failure of the rocket booster and the subsequent explosion - Night before the launch was particularly cold; frost and ice had developed on the rocket; it is believed the cold weather reduced the elasticity of the O-ring preventing it from properly sealing the joint - The Columbia Shuttle Explosion - The Columbia disintegrated on February 1, 2003 upon re-entry into Earth’s atmosphere after spending 16 days in outer space - During launch, a piece of insulation broke off from the external tank - It struck the left wing and damaged the system that protects the wing from intense heat produced by atmospheric gases upon re-entry - Pieces of the shuttle were found in Texas and Louisiana - Formation of the Solar System - Scientists believe a cloud of gas and dust in space was disturbed by a supernova, leading to the formation of the solar system - Supernova: the explosion of a star that has reached the end of its life cycle - This is believed to have occurred 4.6 billion years ago - The Nebular Hypothesis: the supernova explosion made waves in space causing the formation of a solar nebula, a flattened cloud of gas and dust - Formation of the Planets - The centre of the solar nebula grew hotter resulting in the formation of the Sun - The outer edges cooled causing clumps of particles to stick together and form planets - Components of Outer Space - Galaxy: a cluster of billions of stars - Our solar system makes up a tiny portion of the Milky Way Galaxy - Star: a hot glowing ball of gas that generates energy by converting hydrogen to helium - The Milky Way Galaxy - The Sun is located approximately 30 quintillion km from the centre of the Milky Way - It takes light nearly 100,000 years to travel from one side of the galaxy to the other - The Sun - In the core of the Sun, the temperature is 15,000,000 ℃ - The outermost part of the sun is called the photosphere and it is 6000 ℃ - Energy from the sun controls the Earth’s climate system - Sun is so large relative to Earth that it only receives two billionths of the total energy - The Solar System

- The solar system is composed of 8 planets, 214 moons, and millions of bolides - Order of the Planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune - Life Cycle of Stars - The Sun is the closest star to Earth; it has a life expectancy of approx. 10 billion years - At the end of the life cycle of a star, massive amounts of energy are released in an explosion known as the supernova, producing a white dwarf or black hole - Bolide - An extraterrestrial body that originates in outer space - Examples - Asteroids: rocky metallic material in space 10 m to 1000 km in diameter originating in the Asteroid Belt (between Mars and Jupiter) - Meteoroid: similar composition to an asteroid but only up to 10 m in diameter - Meteor: a meteoroid that has entered Earth’s atmosphere - Meteorite: a meteor that strikes the Earth’s surface - Comet: these are distinguishable by a large glowing tail of gas and dust - It is believed that comets originated from an area outside the solar system called the Kuiper belt - Comets - Comets create light as a gases are released while the comet is heated by solar radiation - Halley’s comet is the most famous because it is visible with the naked eye and passes close to Earth every 75 years; last instance was was 1986, next instance in 2061 - Airbursts - Bolides travel at velocities of 12-72 km/s - As they heat up upon entering Earth’s atmosphere, they produce bright light - Many bolides explode at an altitude between 12-50 km; explosion is called an airburst - Tunguska Airburst - The explosion destroyed over 2000 km^2 of forest in a sparsely populated area of northeast Russia in 1908 - Scientists have determined it was an airburst because no crater has ever been found - The asteroid responsible is believed to be 25 to 50 metres in diameter - Chelyabinsk Airburst - On February 15, 2013, a meteor exploded over the city of Chelyabinsk, Russia and is the largest bolide to enter Earth’s atmosphere since the Tunguska airburst - Over 1500 people were injured, mainly from broken glass as a result of the shockwave - Impact Craters - These provide evidence of past meteorite impacts - A layer of debris around a crater, called an ejecta blanket, consists of rock fragments that were blown out of the crater upon impact - A crater seen today is not as deep as the original crater due to erosion and fragmented rock falling back into the crater shortly after the impact - This fragmented rock is referred to as breccia

- Crater is always bigger than the rock itself and the transmission of kinetic energy (shockwaves) to the surrounding ground is responsible for their circular shapes - Impact craters can be defined as either simple or complex - Simple craters: less than a few km in diameter, do not have an uplifted centre - Complex crater consists of a rim that collapse and a centre floor that slowly rises following impact; complex craters are generally greater than 6 km in diameter - Meteor Crater - Crater is in Arizona and was formed about 50,000 years ago by an iron-nickel meteorite - Manicouagan Crater - This complex impact crater is 100 km in diameter and is one of the largest in the world - It is in Central Quebec and was formed 214 million years ago - The rim collapsed and the rock has eroded to form a ring shaped lake - Chesapeake Crater - This crater was not discovered until subsurface imaging and drilling revealed its presence off the coast of Virginia - The crater was formed 35.5 million years ago - Since then, it has been overlain by sediment and seawater as sea levels have risen - Impact Craters on the Moon - Why are craters much more common on the Moon than on Earth? - Most impacts with Earth occur on oceans, thus no craters are produced - Impacts with Earth’s land have been eroded or buried and therefore have more subtle features when compared to the craters on the moon - Smaller bolides often burn up and disintegrate in Earth’s atmosphere before striking its surface; the moon does not have an atmosphere - Shoemaker-Levy Comet - This comet entered Jupiter’s atmosphere in 1994 - Massive amounts of energy were released and gas plumes were produced as 21 fragments of the comet collided with Jupiter - After this impact, it was universally accepted that a similar impact could strike Earth - Mass Extinctions - Extinctions coincide with boundaries of geologic periods on the geologic time scale - These are usually consistent with abrupt changes in climate from volcanism, bolides, or human made impacts on the environment - There have been 5 major extinctions during the past 550 million years and a 6th extinction event is occurring today, Global Warming due to Human Activity - K-T Boundary Mass Extinction - It occurred 65 million years ago from the abrupt cooling caused by a bolide impact - It is named for the boundary separating the Cretatious and Tertiary periods - In some language Cretaceous is spelled with a “K” - This event caused the extinction of the dinosaurs which had been at the top of the food chain for 100 million years; also the extinction of 70% of all plant and animal species

- How was the extinction determined to be from a bolide impact? - Scientists found large quantities of iridium in rock that dating 65 million years - Iridium is a rare element on Earth, but it is found in bolides - The hypothesis of an impact was at first criticised because no crater was found - The K-T crater was discovered in 1991; it is 180 km in diameter and was found underlying sediment and seawater - Yucatan Peninsula in Mexico and is referred to as the Chicxulub Crater - Analysis of the crater suggests the impact produced 10,000 times the energy of the entire nuclear arsenal of the world today - Linkages with other Hazards - Bolide impacts can trigger tsunamis, earthquakes, landslides, and cause climate change - Risk from Bolide Impacts - If a bolide remains in the Asteroid Belt, it poses no hazard to Earth - The orbital path of a bolide could be disturbed by a collision with another object (bolide) - It is estimated that 1100 bolides larger than 1 km in diameter exist with near-Earth orbits - Scientists estimate that an urban area would be destroyed once every 30,000 years by a bolide similar in size to the Tunguska airburst (which has a 1000 year recurrence interval) - Managing the Bolide Impact Hazard - The Spaceguard survey program has catalogued all near-Earth orbits larger than 1 km in diameter and is currently extending the inventory to bolides with diameters of 100 m - If a large bolide is determined to be approaching Earth, it would be detectable decades in advance allowing for the appropriate countermeasures to be taken - Blowing up an approaching bolide will cause fragments to rain down; not advisable - Altering bolide trajectory by ramming it with a spacecraft is the recommended approach - This was tested for the first time in 2022 when a spacecraft impacted the asteroid Dimorphous approximately 11 million km from Earth Chelyabinsk Meteor Documentary 1. What did the nuclear weapons monitoring system reveal about the explosion of the meteor? - Infrasound data revealed a very low tonal frequency; low frequency noise propagates farther than high frequency; low frequency sound waves were able to travel an incredible distance and circled the world several times, registering at stations multiple times throughout the day due to the sheer magnitude of size of the explosion; original estimate of 40-50 kilotons was raised to nearly 500 kilotons of TNT, much more destructive than most hydrogen bombs 2. How do small depressions the size of thumbprints form in meteors? - Depressions the size of thumbprints form in meteors due to little vortices of air that break off indentations of rock away from the falling meteorite 3. Although videos of the event were useful, what were some of the problems with the videos?

- Videos are not calibrated; they show a patch of sky and how the object crosses the sky, there are a lot of missing details that are needed to precisely calculated the parameters of the meteor - Requires going back to the site and figuring out the location and orientation that the original videos were taken to better understand the logistics of the event 4. What were the differences between the Chelyabinsk event and the Tunguska event? - Asteroid was rocky and weakened due to internal cracks that made it vulnerable to explosion early into its descent through Earth’s atmosphere, causing the explosion and shockwaves - Shockwave occurred 15 miles up in the atmosphere and took 3 minutes to arrive - Due to the shallow angle of the meteor’s trajectory and higher altitude explosion, a lot of the downward moving shockwaves were reduced; if the angle were more steep, the downward shockwaves would have caused much more damage, like the Tunguska event - Tunguska event also involved a larger meteor and the airburst explosion occurred closer to the ground, at a lower altitude, than the Chelyabinsk event; thus the explosion was much more intense such that people felt the heat radiation from the shockwaves from the Tunguska event 5. What is NASA planning to do to discover more asteroids in the future? - Question remains, why did no one see the Chelyabinsk meteor despite NASA monitoring the large DA14 meteor during the same time period? - We commonly think that the meteorites hit Earth, however the trajectory of the meteor shows that Earth “hit” the meteor, intercepting its path - NASA tracks known asteroids and finds new ones to track everyday, but they had primarily focused on the larger asteroids that would have greater potential for damage - NASA plans on deploying an infrared telescope in space since these asteroids radiate strongly in the infrared signal; it would allow for the detection of asteroids at a significantly earlier time and with greater accuracy for smaller asteroids Lecture 9 - November 27, 2023 - Snow Avalanche - A mass of snow many cubic metres in volume that separates from a snowpack and moves downslope; rocks, soil, ice, and debris can travel in a similar motion, however the term avalanche is generally reserved for snow - Intensity is dependent on slope steepness, snowpack stability, and weather - There are two types: - An avalanche travelling as a coherent block - An av avalanche that becomes wider as it travels downslope - It is estimated that over 99% of avalanches are not seen by anyone, because they occur in regions that not many people inhabit - It is likely that over 1 million avalanches large enough to kill a person occur annually in Western Canada alone - Snow Climatology

- The amount of snowfall in an area depends on its latitude, altitude, and proximity to bodies of water; temperature decreases with altitude therefore high mountains have permanent snow cover at higher altitudes - Snow Cover - The probability of a White Christmas considers the probability of snow cover on Dec. 25 - Snow cover maps are updated daily - Types of Avalanches - Point Release Avalanche - It begins as an initial failure in the snowpack after a heavy snowfall - The sliding snow then causes more failures in the adjacent snowpack causing the trough of the avalanche to widen and drag more snow along with it - Slab Avalanche - It occurs when a snowpack fractures along a weak layer parallel to the surface - These avalanches move as cohesive blocks leaving behind a scarp - They are the most dangerous avalanches - Avalanche Potential - New snow that has not been able to bond to the layer below is susceptible to sliding - Wet, compacted snow is less likely to slide than dry, powdery snow - A mass of snow that has total elevation above the vegetation level and above large boulders is more likely to slide; vegetation and boulders act as anchors to prevent sliding - Weak Layers - Slab avalanches require a buried weak layer - Such a layer can form from wind or from hoar - Wind - Blowing snow can accumulate on the lee slope of mountains - Lee slope is the downwind slope of a hill or mountain; wind carries loosely packed ice crystals onto the lee slope, the other slope consists of compacted wetter snow as a result - Wind can deposit a layer of light ice crystals on a layer of more compacted snow - The boundary between the two layers could become a horizon along which failure could occur - Hoar (hoarfrost; frost, formation of ice crystals from water vapour) - Layers composed of hoar have less strength than the rest of the snowpack - Hoar can form deep in the snowpack (in air pockets) or on the snow surface - Hoar changes little over time; therefore, overlying snow can leave the buried hoar as a weak layer - Avalanche Motion - Rapidly moving avalanches (over 35 km/h) often generate clouds of powdered snow - The fastest avalanches have been measured at speeds near 200 km/h - Some avalanches are powerful enough to climb opposing slopes (go uphill)

- Only possible if a large avalanche occurring in a valley, to ride the next slope - Avalanche Triggers - Most avalanches occur soon after snowstorms - Some may occur when daytime heating from the Sun warms the upper part of the snowpack, melting snow trickles down into deeper layers, lubricating them - Avalanches that cause injuries or fatalities are often triggered by people - Some avalanches are triggered intentionally with explosives - Avalanche Paths - Start Zone: the area where the snowpack first fails - Track: the area where the avalanche accelerates and reaches maximum velocity - Run-out Zone: the area of deceleration and snow deposition - Terrain Factors - The slope angle is the most important terrain factor that influences avalanche formation - Most avalanches occur at slope angles between 25 to 60 degrees - Higher risk is from 30-45 degrees - At angles below 25 degrees, snow does not easily slide - At angles above 60 degrees, little snow can accumulate on the slope - The orientation (direction) of the slope can also be a factor - Snow deposited on leeward slopes can consist of interlayered strong and weak layers, thus common wind direction is an important factor - Slopes facing the sun are more prone to daytime avalanches - Other factors include the smoothness of the slope, the amount of vegetation, and the topography of the slope itself - Regions at Risk - For an avalanche to form, a snowpack of at least 50 cm is typically required - In North America, deep snowpacks are most common in the Rocky Mountains - Effects of Avalanches - In Canadian history, most avalanche deaths occurred in the late 1800s and early 1900s - Gold Rush in Yukon - Construction of the Trans-Canadian Railroad - In total, over 600 people have died from avalanches in Canada - Avalanches cause millions of dollars in economic losses in B.C. each year due to closed highways on the mountains that connect to the province - Damage to forests is evident each year but property damage is relatively minor - Chilkoot Avalanche - This disaster occurred in 1898 and remains one of the worst avalanches in NA history - An avalanche spread over the Chilkoot trail causing 60 deaths - The trail was heavily used at that time during the Klondike Gold Rush - Chilkoot Trail extends from Alaska to B.C. and is the easiest route through the mountains - Linkages to other Natural Hazards - Avalanches can be caused by earthquakes

- Climate change may increase winter snowfall in some areas and increase severity of winter storms thus increasing the likelihood of avalanche occurrences - Some areas will experience more thaws in winter enhancing the instability of snowpacks - Natural Service Functions - Like landslides, avalanches act as an ecological disturbance - This may increase local plant and animal diversity - Avalanches maintain open areas in otherwise forested regions; prevent growing trees - This can serve an as important habitat zone for certain plants and animals where constant avalanches in a region can maintain a clearing/open area in the terrain - Human Interaction with Avalanches - Avalanches are only a hazard when humans encroach on areas that are prone to them - As tourism and recreation have increased in the Rockies and the Alps, human deaths from avalanches have increased over time; increased triggering due to human activity - Minimising Avalanche Risk - Risk is greatly reduced when buildings, roads, and other infrastructure are located away from known avalanche paths; trigger avalanche to observe its regular path - Hazard maps provide planners with locations of the highest risk areas to avoid - Buildings in hazardous areas within a specific recurrence interval may require special engineering; this may include reinforced walls or deflection structures - In avalanche start zones, fences or nets can be installed to stabilise the snowpack - Mounds or berms can be used to slow/deflect avalanches away from populated areas - Splitting wedges on the sides of buildings can force an avalanche around a structure to protect it from the brunt of the force, diverting snow to either side of the building - Avalanche sheds allow avalanches to travel over roads or railways without disruption to traffic; essentially a tunnel that protects vehicles and traffic from avalanches above - Controlled triggers are used to force avalanches to occur to prevent the build-up of the snowpack, this is commonly performed using explosives - Avalanche Forecasting - Forecasting is based on: - Location of past avalanches - Strength and stability tests - Snowpack observations - Weather - Strength and Stability Tests - There are three major tests used to assess a snowpack - Compression test - A vertical force is placed on the top of the snowpack to detect weak layers - Shovel test - A column of snow is isolated and then a force is applied on the uphill side - Rutschblock test - A skier pushes and jumps on a column of snow to determine the cohesion of a snowpack (more accurate test than the others)

- Avalanche Safety - Before travelling in an avalanche prone area, it is important to check the current danger level as well as any public bulletins; lowest level of danger is ‘low’ there is no ‘no’ danger - Knowledge of slope angles and the terrain is also necessary - Avulator - The Canadian Avalanche Centre has developed the Avulator - It is a chart designed to warn travellers of the risk of an avalanche in an area - Avalanche Rescue - The motion of the snow itself kills about 25% of avalanche victims - Survival depends on the length of time the person is buried and burial depth - Over 90% survive if rescued within 15 minutes, 30% within 35 minutes, 0% w/ 2 hours - Buried victims die of a combination of suffocation and hypothermia - Less than 10% of victims survive burial in more than 1.5 m in snow - The best chance of survival depends on an effective immediate search by other members of the group rather than waiting for help - Chances of finding a buried victim increase when everyone in the group carries standard avalanche survival aids - Avalanche Survival Aids - Avalanche Cord - A 10 m rope that drags behind a person while skiing, snowboarding, or snowshoeing; a red rope with yellow markers every 1 m that can aid in detection and figuring out how deep a person is buried - Avalanche Transceiver - A portable device that emits a radio signal to assist in finding the burial location - Avalanche Dogs - They can detect human scent rising through the snow and can quickly cover large areas due to their amazing sense of smell Lecture 10 - December 4, 2023 - Wildfires - Wildfires date to the time when trees first evolved 400 million years ago - The most common causes of natural wildfires are lightning and volcanic eruptions - After a fire, vegetation completes a cycle: early colonising plants to mature ecosystem - The new ecosystem that evolves adapts to the climate of that location and time - Adaption to Wildfires - Many species have evolved to either withstand fire or promote the life and survival of the species after a fire event - Redwood and oak trees have bark that resists external fire damage - Some pine trees have cones that only open after a fire; protecting seeds - Wildfires through History

- The geologic record shows an increase in the amount of charcoal in sediment dated to approximately 10,000 years ago suggesting a high amount of wildfire activity at the time: - A warmer and/or drier climate - Increased use of fire by humans for clearing land and for heat, cooking, etc. - Elements of Wildfires - Wildfires require three elements: fuel, oxygen, and heat - If any of these are lost, the fire will dissipate - Plants absorb carbon dioxide and store carbon in their tissues - During a wildfire, this carbon dioxide is released back into the atmosphere - Amount of CO2 from wildfires is considered negligible to climate change - There are three phases to a wildfire: pre Ignition, combustion, and extinction - Pre-ignition Phase - Pre-heating - During this phase, vegetation reaches a temperature at which it can ignite - As vegetation is heated, it loses water (transpiration) and dries out - Heat radiating from the flames of a wildfire can pre-heat nearby vegetation - Combustion Phase - Pre-heating results in fuel that is prone to ignite - Combustion begins with ignition that could be from a natural (lightning) or human cause - Not all ignitions will result in wildfire; vegetation must already be dry from pre-heating - Types of Combustion - Flaming combustion is the rapid, high temperature conversion of fuel into heat - It is characterised by large flames and a high amount of unburned material - Smouldering combustion occurs in areas with ash and already burned material - Heat Transfer - As a wildfire moves across the land, three process control the transfer of heat - Conduction - Transfer of heat by solid-to-solid contact - Radiation - Transfer of heat in the form of invisible waves - Convection - Transfer of heat by movement of a liquid or a gas - Heat Transfer by Wildfires - In wildfires, heat transfer is mainly by radiation and convection - Heat from radiation increases the surface temperature of the fuel - As air is heated, it becomes less dense and rises; warmer air is less dense and rises - The rising air removes heat from the zone of flaming, and it is replaced by fresh air - This fresh air is rich in oxygen and sustains the combustion event - Extinction Phase - In this phase, combustion has ceased - There is no longer sufficient heat or fuel to sustain a fire

- Fuel - Types of fuel include leaves, woody debris, decaying organic material, grasses, etc. - If diseases/ storms down many trees, the decaying material dries and burns easily - The density of the forest plays a role: - In Western North America, dense boreal forests contain abundant fuel supplies - Topography - The risk of fire can vary by slope orientation - In the Northern Hemisphere, south-facing slopes are relatively warm and dry - Sun is in the South-Eastern sky in the afternoon; moss grows on the North side because there is less sun exposure thus providing a damp environment - Slopes exposed to prevailing winds are often drier - Wildfires burning on steep slopes preheat fuel upslope from the flames - Fires cannot travel downslope easily because heat wants to rise - This results in the rapid spreading of a fire upslope - Weather - Large wildfires are most common following a drought - In a dry thunderstorm, the rain evaporates before reaching the ground due to the dry climate; lightning from these storms are more likely to produce wildfires - Wind can enhance preheating of fuel - Wind also carries embers that ignite spot fires ahead of a main fire front - Types of Fires - Wildfires are classified according to the layer of fuel that is allowing the fire to spread - Surface fires travel close to the ground and burn shrubs, leaves, twigs, grass, etc. - They vary in intensity but most move relatively slowly because there is a lot more fuel to burn through; takes time to convert fuel to heat - Crown fires move rapidly through the forest canopy by flaming combustion - They can be fed by surface fires that move up limbs or tree trunks - Or they may spread independently of surface fires - They are driven by strong winds and are more common in boreal forests - Crown Fires - Intermittent crown fires consume the tops of some trees in an area - Continuous crown fires consume the tops of all trees - Effects of Wildfires - Fires that burn soil may leave behind a hydrophobic ash layer at the surface - This layer is caused by the accumulation of chemicals from burned vegetation - Since the layer repels water, it increases surface runoff and erosion - It may persist for several years following a fire - An increase of airborne particles and haze from wildfires can be observed thousands of km downwind of large fires; this is the result of jetstreams carrying the smoke - Regions at Risk - In Canada, the wildfire risk is greatest in British Columbia and in the boreal forests of the Canadian Shield region

- The geographic region most at risk changes annually with the weather and corresponds to areas that are experiencing drought - Yellowstone National Park Wildfire - A series of lightning strikes caused 50 fires in the park in 1988 - Park officials have a policy that allows naturally caused fires to burn without intervention - This became controversial; hot, dry weather that summer allowed fires to spread/merge - Officials responded to political pressure, eventually calling in nearly 10,000 firefighters - The fires were beyond the control of the crews and burned for several months - The fires became uncontrollable because many years of fire-suppression policies in the past had allowed fuel amounts in the park to reach dangerous levels - The fires of 1988 revitalised ecosystems in the park - Officials remain committed to the natural burn policy today - This is a common policy in national parks - Forest Fires in Canada - More land area in Canada burned in 2023 than in any year in history - In the year 2100, it is predicted that all regions in Canada will face increased risks of fires - Fort McMurray Wildfire - The wildfire in 2016 caused $10B in damage; costliest disaster in Canadian history - There were no deaths or injuries due to the evacuation of the entire city in advance - Residents were displaced for four weeks and over 2000 people lost their homes - The cause of the fire has not been determined - A prolonged drought occurred in the area during the prior winter and record high temperatures occurred in the preceding days - Linkages to Climate Change - Climate change increases the likelihood and the intensity of wildfires - Climate change affects both temperature and precipitation and can lead to severe droughts; hence why it is not called global warming since precipitation is involved - In some parts of the world, grasslands will replace forests; current areas of forest will expand poleward where there is relatively less Sun intensity - Insect infestations can cause disease throughout a forest, making it vulnerable - Mountain Pine Beetle - The beetle has destroyed 80% of mature Mountain pine forests in British Columbia - The economic consequences will be felt for decades in the B.C. interior (not coast) - The beetle is also posing a threat to Jackpine forests in Alberta - With warmer seasonal temperatures (as a result of climate change), the beetle has evolved to survive through the winter in B.C. - Impacts of Wildfires - Fires can lead to evacuations, road and airport closures, and severe property loss - In North America, organised evacuations have minimised the number of deaths - Exposure to smoke and haze can affect the ocular and respiratory systems - Impacts on Animals

- Most animals escape fires unharmed - Rodents can take refuge underground and larger animals can outrun the fire - Fires can produce open areas suited for grazing mammals - Thus acting as a natural service function - Aquatic species may be negatively impacted by sedimentation from runoff and erosion - Natural Service Functions - Wildfire temporarily reduces competition for sunlight and moisture in a forest - Allows both surviving and new species to thrive by allowing sunlight to reach the floor - In some species, fire triggers the release of seeds or stimulates flowering - Lodgepole pine, aspen, and fireweed are examples of pioneer vegetation that grow quickly after a fire; pioneer vegetation: the first plant species to appear after a wildfire - Wildfire Management - The objective is to control wildfires for the benefit of ecosystems while preventing them from harming people and destroying property - In Canada, the fire season is from April to October - Managed by provincial/territorial governments - Good management requires research of the fire regime of an area - Fire regime: the potential for wildfire - Satellite imagery is providing insights on fire potential in remote areas - Extinguishing Wildfires - A strategy is to steer the wildfire toward an area with no fuel (a fire break) - Rivers, lakes, and roads could all act as firebreaks - If a natural firebreak does not exist, an artificial break can be created from bulldozers clearing land - Prescribed Burns - One way to counter excessive fuel in an area is through a prescribed burn - These are controlled fires that are purposely ignited to reduce fuel in an area - Difficulties and risk relate to weather conditions under which the fire can be safely controlled - Perception of the Wildfire Hazard - Population growth in areas that are prone to wildfires has increased risk to public safety - Each year, thousands of people move to locations in California that are considered a high risk for wildfires Megafires Documentary 1. How is a fire traditionally studied from a meteorological standpoint? - Satellite to visualise plumes of smoke from the wildfire that can propagate the fire itself; visible and infrared images of the fire to follow the origin/spread (speed) of the wildfire - Lidar to measure wind rotation within the plume from fire-induced wind (movement of fresh air into spaces previously occupied by rising heated air)

2. In the laboratory, what was the effect on the plume when it was starved of air coming in from the sides? What was the name given to this effect? - Flame height significantly increases as cooler air from underneath is the only source of fresh oxygenated air (fanning the flames), this can eventually lead to fire whirls that are transient or even progression to more stable fire tornadoes; chimney effect - Normally, air that comes in from the sides gives the fire its flickering effect, but when the only source of air is forced from underneath the fire, it results in height amplification 3. How did the approach toward wildfire change in the 1970s? - 10AM policy was abandoned where fire was supposed to become more incorporated into wildlife control; prescribed burns are encouraged; wildfires are not attacked but managed and allowed to burn wherever and whenever if possible; the disruption of the fire cycle from the 10AM policy eventually demonstrated the futility of aggressively battling every wildfire and revealed how a century of avoiding fires has set up forests for more constant burning events 4. How did a manual thinning of a ponderosa pine forest impact the growth of trees in that forest afterward? Describe the appearance of the forest afterward. - Where they thinned the trees and conducted a prescribed burn; open space with not a lot of fuels, only larger trees are present thus the density of the forest is low and provides less fuel for fires - Remaining trees after thinning and prescribed burn were able to grow a lot more because of the removal of younger and weaker vegetation that competes for resources 5. Main concern regarding wildfire frequency that occurs on a 15-to-20-year interval? - Climate change making it harder for forests to be resilient after wildfire events; especially if a forest encounters another forest fire event after already suffering one, with its compromised recovery and vulnerable state (different composition of dead vs living vegetation), this could lead to even more severe fires in the region Reading 3 Questions 1. Describe what occurs in the lead-up to a megathrust earthquake. In the lead up to a megathrust earthquake, the tectonic plates move toward one another continually, but can get stuck when in contact, creating over long periods of time, an immense build-up of strain that eventually exceeds the friction between them; when that point is reached, an earthquake occurs 2. How does a core sample from the ocean floor reveal a past earthquake event? Anomalous band of rock and chunk of wood debris that interrupt the core’s muted brown (of rock) tells a violent story: thousands of years ago, a megathrust earthquake rumbled through Vancouver Island, triggering a landslide, the debris footprint of which had been captured in the core sample. 3. Why was the Christchurch earthquake of 2011 a surprise to scientists?

Scientists were surprised because they didn’t even know there was a fault in the region until an earlier earthquake that occurred in September 2010. 4. What is the proposed reason for the seismic activity on Baffin Island in Nunavut? Seismic activity may be caused by the ground slowly rising thousands of years after the glaciers that once covered it melted, a movement known as post-glacial rebound 5. What is currently occurring on Vancouver Island that provides a clue to a potential future earthquake there? Surface of the island is currently bulging up two millimetres per year on its western edge; provides models of where the North American plate and Juan de Fuca plate are locked and storing the greatest amount of energy with a megathrust event on the eastern edge of the potential rupture zone 6. What are the beneficial applications of the motion sensors that Oceans Network Canada is currently prototyping on Vancouver Island? Motion sensors allow for rapid detection and reporting of spreading seismic waves before they reach Vancouver and Victoria; applications such as airports stopping planes from taking off or landing, gas companies turning off their supply, closures of bridge entrances; prevent secondary impact 7. How have the Indigenous Peoples on the west coast of the island been preparing for a potential tsunami? Built their Big House (community living place) on an elevated hill across the river and building more structures on elevated land; also running tsunami drills to practise evacuating to high ground 8. Based on the window forecasted by the scientists at the Sidney laboratory, in what time range will the next strong earthquake occur in the region? (Provide the range by giving the specific years). 320 years is Randy Enkins window of megathrust earthquake recurrence; last occurrence was 1700 Reading 4 Questions 1. Explain the importance of the Sundarbans. Sundarbans is the world’s largest contiguous mangrove forest; flood-tolerant trees, a greenwall that absorbs storm surges and blunts even the worst cyclones; abundant source of honey for villagers and its waters are an important source of fish 2. Give two reasons why more salt water is entering into the mangroves. Upstream dams on rivers in India have reduced freshwater flow into the Sundarbans, while sea level rise caused by climate change is flushing more salt water into the mangroves 3. In the worst-case scenario, by how much would sea levels rise this century? In the worst case scenario, sea levels are predicted to rise by more than six feet this century

4. Why have some islands in the region completely disappeared? Without the tangled roots of the mangroves to stabilise the land, it erodes into the sea, and with upstream dams trapping river sediment, the land is not replenished as it once was 5. How has the situation impacted rice production in the region? Rice yields during the 2018 dry season harvest were way down, often well under a ton an acre, which pushed up food prices ; vegetables wouldn’t grow in salty soils 6. Why have death tolls been decreasing even though the population is increasing, and cyclones are strengthening? There has been an effort to heavily reduce the amount of mangrove cutting to strengthen the natural protection; government has built more cyclone structures and deploying trained volunteers 7. Explain why the future of the Sundarbans appears to be grim. The construction of a large, Indian-backed, coal-fired power station at Rampal, on the edge of the Sundarbans, has been approved; this could encourage the introduction of other polluting industries; China is proposing more dams that could jeopardise the mangroves’ remaining freshwater supply; climate keeps changing with more erratic rains, storms and temperature swings