Volcano Webquest - Copy

Dryeska Bernardino Volcano Webquest Go to each of the websites indicated below. Answer the questions or complete the requested response about each of those sites. Make sure your explanations to the answers are as complete as possible. https://www.usgs.gov/natural-hazards/volcano-hazards/about-volcanoes 1. What is a volcano and how are they formed? Volcanoes are openings, or vents where lava , tephra (small rocks), and steam erupt on to the Earth's surface. Many mountains form by folding, faulting, uplift, and erosion of the Earth's crust . Volcanic terrain, however, is built by the slow accumulation of erupted lava. The vent may be visible as a small bowl shaped depression at the summit of a cone or shield- shaped mountain. 2. Explain how volcanoes erupt. Be sure to include actions of magma in your explanation. Molten rock below the surface of the Earth that rises in volcanic vents is known as magma, but after it erupts from a volcano it is called lava. 3. How many volcanoes can be found in the United States? scientists have identified 161 volcanoes within the United States that most likely will erupt at some point in the future. Most of these volcanoes are located in Alaska, a state where eruptions occur almost every year. 4. How many volcanoes can be found worldwide? There are about 1,500 potentially active volcanoes worldwide, not counting the volcanoes under the oceans. 5. In the chart below, summarize the characteristics for the main types of volcanoes Cinder Composite/Strato Shield Lava Dome They are made of small pieces of solid lava, called cinder, that are erupted from a vent. The ground shakes as magmarises from within the Earth. They are usually tall with steep even sides and are made out of repeating layers of lava flows, volcanic ash, cinders, blocks, and volcanic bombs. Shield volcanoes are built almost entirely of fluid lava flows. Lava p ours out of vents in all directions, either from the summit (top) or along two to three rift zones (fractures) that radiate out from the summit like spokes on a bicycle wheel. Lava squeezes out of the vent and accumulates as a giant pile over and around the vent. Some domes form pointy spines, while others appear as a giant muffin, as opening flower petals, or as steep- sided stubby flows or tongues. http://volcano.oregonstate.edu/what-is-a-hot-spot 1. Explain what a hot spot is. Hot spots are places within the mantle where rocks melt to generate magma. The presence of a hot spot is inferred by anomalous volcanism (i.e. not at a plate boundary), such as the Hawaiian volcanoes within the Pacific Plate. 2. Use your knowledge of hot spots, explain the formation of the Hawaiian islands.

https://www.pbs.org/wgbh/nova/article/volcano-parts/ 1. In the chart below, summarize the anatomy of a volcano Ash Lava flow Lave Dome Volcanic ash consists of rock, mineral, and volcanic glass fragments smaller than a tenth of an inch in diameter—or slightly larger than a pinhead. Volcanic ash is quite different from the soft, fluffy ash that results from burning wood, leaves, or paper. Lava flows are masses of magma that pour onto the Earth's surface during an effusive eruption; they include both moving lava and the resulting solidified deposits. lava domes are rounded, steep-sided mounds built by magma that is highly resistant to flow, usually either dacite or rhyolite. Lava Vent Tephra Lava is the word for magma when it erupts onto the Earth's surface. Geologists also use the term to describe the solidified deposits of lava flows and fragments hurled into the air by explosive eruptions (for example, lava bombs or blocks). Vents are openings in the Earth's crust from which magma and volcanic gases escape onto the ground or into the atmosphere Tephra is a general term for fragments of volcanic rock and lava that are blasted into the air by explosions or carried upward by hot gases in eruption columns or lava fountains. Tephra includes large, dense blocks and bombs, and small, light rock debris such as scoria, pumice, reticulite, and ash. Caldera Lahar Fissure is a large, usually circular depression at the summit of a volcano formed when magma is withdrawn or erupted from a shallow underground magma reservoir. is an Indonesian word for a rapidly flowing mixture of rock debris and water that originates on the slopes of a volcano. Lahars are also referred to as volcanic mudflows or debris flows. On volcanoes, a fissure is an elongated fracture or crack at the surface from which lava erupts. Fissure eruptions typically dwindle to a central vent after a period of hours or days. Dike are tabular or sheet-like bodies of magma that cut through and across the layering of adjacent rocks and then solidify. 2. Label the parts of the volcano in the diagram below. Use the word bank to help. Word Bank: Lava Conduit Secondary Cone Magma Chamber Ash Cloud Crater

very fluid basalt -type lavas with low gaseous content . Peléan Plinian are a type of volcanic eruption named after the volcano Mount Pelée in Martinique , the site of a Peléan eruption in 1902 that is one of the worst natural disasters in history. are a type of volcanic eruption named for the historical eruption of Mount Vesuvius in 79 AD that buried the Roman towns of Pompeii and Herculaneum and, specifically, for its chronicler Pliny the Younger . 2. Explain how volcanic eruptions are rated. Include the name and how it is used. Tambora Volcano Eruption - The Year Without A Summer: https://www.yout0ube.com/watch? v=r676EnIp8yg 1. What is the VEI index? Is a relative measure of the explosiveness of volcanic eruptions. 2. What is the difference between a rating of 0 and 8 on the VEI? A value of 0 is given for non-explosive eruptions, defined as less than 10,000 m 3 3. What was the VEI for the Tambora eruption of 1815? 4. How long did the eruption of 1815 last? Its eruption reached a violent climax on 10 April 1815, increased steaming and small phreatic eruptions occurred during the next six months to three years. 5. What happened to the village located at Tambora in 1815? The most destructive explosion on earth in the past 10,000 years was the eruption of an obscure volcano in Indonesia called mountTambora. 6. What happened to the global temperature due to the eruption of 1815? A shattering blast blew the mountain apart on the evening of April 10. 7. What was the worldwide effect of the eruption of 1815? (need a minimum of 3) 8. How many people died during the Mount St. Helen eruption in 1980? 40 years ago 9. Where do we find 75% of the worlds volcanoes? The ring of fire