Guided Lab - Volcanoes-2

GUIDED LAB - VOLCANOES To receive credit for this guided lab, please type your answers in this document and upload your completed document to the I-Learn assignment. There are boxes for you to include your answers. LEARNING TARGETS At the end of this guided lab, you will be able to  Identify the relationship between volcano type, rock type, typical tectonic setting, and explosivity.  Predict the volcano type, rock type, typical tectonic setting, or explosivity using this relationship. PART 1 – VOLCANO EXPLOSIVITY Watch the following two videos showing two different eruptions. While you are watching each video, write a description of your observations. Bardarbunga, 2014 https://youtu.be/I2_EteXm9QI Description: Eyjafjallajökull, 2010 https://youtu.be/e-TMtRh8AIs Description: 1. Which eruption was more explosive ? 2. Which eruption was more effusive ? 3. Which volcano had darker rocks? 4. What do you know about lighter igneous rocks and explosivity? PART 2 – IDENTIFYING VOLCANO PATTERNS BIG PICTURE QUESTIONS  Why were these eruptions so different?  Could we have predicted that one eruption would have been more explosive than the other? TECTONIC SETTINGS We are going to use Google Earth to look at the tectonic setting of different types of volcanoes. The four tectonic settings where volcanoes are: Eyjafjallajökull Bardarbunga Bardarbunga Tuff is an igneous rock that forms from the products of an explosive volcanic eruption. In these eruptions, the volcano blasts rock, ash, magma and other materials from its vent.

 Convergent Plate Boundaries : Volcanos typically occur at subduction zones.  Divergent Plate Boundaries : Most volcanos are found at divergent plate boundaries. These boundaries can be oceanic-oceanic crust or continental- continental crust. Both have volcanic activity.  Oceanic Hotspots : Oceanic hotspots produce volcanoes in the middle of an oceanic plate far away from a plate boundary.  Continental Hotspots : Continental hotspots produce volcanoes in the middle of a continental plate far away from a plate boundary. OPEN GOOGLE EARTH First, download and open the Plate Boundary file. Google Earth Desktop 1. Download “Plate Boundaries.kmz” and save it to a location you can find. 2. Open “Plate Boundaries.kmz” Google Earth Web 1. Download “Plate Boundaries.kmz” and save it to a location you can find, your Google Drive is a good location. 2. Launch Google Earth on the Web: https://www.google.com/earth/ 3. Click the projects icon . 4. Click Open , then Import from where ever you saved the kml file . 5. Click the projects icon to close the side bar. 6. Click the Map Styles icon . 7. Then choose “Clean” to display only the terrain. SMITHOSIAN INSTITUTION GLOBAL VOLCANISM PRGRAM The Smithsonian Institution Global Volcanism Program has the largest database of volcanoes and eruptions. We are going to use the database to look for patterns in volcano shapes, rocks, tectonic setting and explosivity. https://volcano.si.edu/search_volcano.cfm INSTRUCTIONS

o This will “fly” you to the volcano location. . Does it look like the type of volcano you wrote down? o Zoom out to see if the volcano is near a convergent or divergent plate boundary. . If it is, write the type of plate boundary in Tectonic Setting . If is not near a plate boundary, determine whether it is at a continental or oceanic hotspot.  Either way, you should have recorded the Tectonic Setting with one of the following: Divergent, Convergent, Continental Hotspot, or Oceanic Hotspot. Repeat this process for each of the volcanoes on the list, then find three more volcanoes on your own to complete the last three rows of the table.

Searching for Volcano Patterns Volcano Name Volcanic Subregion Primary Volcano Type Dominant Rock Type Last Eruption Biggest VEI Latitude Longitude Tectonic Setting Hell’s Half Acre Shield basaltic 3250 BCE ± 150 years about 400 km2 SW of Idaho Falls. 43.49 - 112.44 8 Manda Hararo basaltic shield basaltic In 2009 105-km- long 12.17 40.815 Mauna Loa Shield olivine basalts Nov 27 2022 376 million cubic meters 19.469 - 155.59 6 Theistareykir basaltic hyaloclastites and pillow lavas . April 2010 65.878 -16.844 Atacazo Stratovolcano Basaltic 320 BC -0.357 -78.624 Dana calc-alkaline 55.641 - 161.21 4 The Quill stratovolcano Psychedelic about 1,600 years ago 17.478 -62.963 Romeral stratovalcano Pliocene-Holocene 5390 BC 5.203 -75.363 Cerro Blanco - 26.789 -67.765 Chaiten - 42.837 -72.651

FINDING PATTERNS IN DATA Did you notice any patterns? PART 3 – USING VOLCANO PATTERNS TO MAKE PREDICTIONS We are going to be using the patterns and data to make predictions about volcanoes. 1. Would you expect a volcano made of basalt to be very explosive? Explain why using information from your table. 2. Rank the following rock types from least to most explosive: andesite, basalt, rhyolite. Explain why using information from your table. 3. Mt. Adams is a stratovolcano in Washington State. What type of rock would you expect Mt. Adams to be primarily made of? Explain why using information from your table. 4. What type of rock would you expect to find at each of the following volcano types? Explain why using information from your table. (Inference) a. Caldera b. Shield c. Stratovolcano 5. You hear several people say that when Yellowstone erupts it is going to be a big one. Yellowstone is a caldera volcano. Would you expect an explosive eruption from Yellowstone? Explain why using information from your table. (Inference) Basaltic eruptions are the most common form of volcanism on Earth and planetary bodies. The low viscosity of basaltic magmas inhibits fragmentation, which favours effusive and lava-fountaining activity, yet highly explosive, basaltic (50% SiO2); andesitic (60% SiO2); and rhyolitic (70% SiO2). Basaltic magma has a low viscosity whereas rhyolitic magma has a high viscosity. Most of the volcano is made of andesite together with a handful of dacite and pyroclastic flows which erupted early in Adams' development. The present main cone was built when Adams was capped by a glacier system tuff, rhyolite, and other igneous rocks sually basalt but can be constructed of mostly Andesite

6. Rank the following volcano types from least to most explosive: caldera, shield, stratovolcano. Explain why using information from your table. 7. What type of volcano would you expect to find near a divergent plate boundary? Explain why using information from your table. 8. In what tectonic settings would you expect to find the following volcano types? Explain why using information from your table. (Inference) a. Caldera b. Shield c. Stratovolcano If Yellowstone ever had another massive eruption it could spew ash for thousands of miles across the United States, damaging buildings, smothering crops, and shutting down power plants. it would be a huge disaster Rift volcanoes. Rift volcanoes form when magma rises into the gap between diverging plates. Caldera tectonic setting Calderas are large-scale Shield volcanoes are found on divergent plate Stratovolcanoes typically form at