EQ_Tect_Activity

Lab Activity: Earthquakes, Volcanoes and Plate Tectonics In this exercise we will be investigating websites where you can explore recent earthquakes and volcanoes, and we will be evaluating these events in their plate tectonic setting. I encourage you to explore these websites more in depth where you will find a wealth of information. We will also be exploring more around the Hawaiian Islands, and how the ages of these islands provided a key piece of evidence for Plate Tectonics. For this exercise you will need 4 KMZ files: EQ_Tect_Activity.kmz,, plate_boundaries.kmz, Alaska Volcanoes.kmz, and USGS_Earthquakes_6mo_20231012.kml. I recommend the following settings for Google Earth to make this assignment easier to complete. Web Version ( https://earth.google.com ). Google Earth Pro • Clear out all previous KMZ layers EXCEPT plate_boundaries.kmz Set View to “Clean” • click on “Layers”, select “Clean” . This will make it easier to view the various layers in this file Turn off Borders and labels. • In the “Layers” panel on the sidebar unclick “Borders and Labels” Part 1. USGS Earthquake Information Go to the USGS Earthquake Hazards Website ( https://www.usgs.gov/programs/earthquake-hazards ). To get information on recent earthquakes, click on “Latest Earthquakes” (see Figure 1). Figure 1. USGS Latest Earthquakes Mapping Tool

Questions: 1A. In the selection panel (at right – figure 1), select “1 Day, All Magnitudes U.S.” option. Make sure the “Only list Eq…shown on map” option is TURNED OFF. What was the most recent earthquake and what was its magnitude? 1B. In the selection panel, select “30 Days, Significant Worldwide”. S ort the data by magnitude – largest first. Where was the largest magnitude earthquake in the past 30 days in the world and what was its magnitude? Click on the largest magnitude earthquake on the left panel and select the link to the Earthquake Overview page (See figure 2). Questions: 1C. (no question here…) On the Overview Page (figure 2) – scroll down and click on “Download Event KML” (save this to your computer and remember where!). The “Nearby Seismicity” link brings up a map with all the earthquakes in the past month within ~250 km. 1D. How many earthquakes have there been in the vicinity of this earthquake, and what is the range of magnitudes? Go to Google Earth (Google Earth Pro, or Web Version). Open the “plate - boundaries.kmz” and the KML file that you downloaded in step 3 above into Google Earth. 1E. Is this earthquake near (~within 250 km) of a plate boundary?__________. If so, what type of plate boundary is it?__________________. What plates are coming together at this boundary? (see figure 3 for plate boundary legend and Table 1 for list of plate boundaries). Figure 2. Navigating Earthquake Overview Page Nevada/0.8 46km SE of Madang, Papua New Guinea/ 6.9 35 earthquakes/ 4.0-6.9 yes Convergent plate boundary Pacific Plate/ Australian-Indian Plate

Part 2: Earthquakes and Plate Tectonics For this exercise you will need to open the EQ_Tect.kmz, plate-boundaries.kmz, and USGS_Earthquakes_6mo_20231012.kml files. The earthquake file includes all earthquakes > 4.5 worldwide for a 6 month period (from 4/12 – 10/12/2023) downloaded from the USGS Earthquake site explored in Part 1 of this exercise. Open the folder “Part 2 Poin ts” in the “ EQ_Tect.kmz ”. For each of the locations in this folder, answer the questions below. Peru 2A. What type of convergent plate boundary is this (Continent/Continent, Ocean/Continent,)? 2B. What is the range of depths of earthquakes (see figure 4)? Is there a pattern to the depth of earthquakes relative to the plate boundary? Explain Iceland – and surrounding Ocean. 2C. What type of plate boundary is this (convergent/divergent/transform)? 2D. What is the range of depths of earthquakes? Is there a pattern to the depth of earthquakes relative to the plate boundary? Explain. Tonga Trench 2E. What type of convergent plate boundary is this (Continent/Continent, Ocean/Continent,)? (ignore the divergent plate boundary here. Sometimes there is a small amount of sea floor spreading behind an island arc structure). 2F. What is the range of depths of earthquakes? Is there a pattern to the depth of earthquakes relative to the plate boundary? Turkey 2G. What type of plate boundary is this (convergent/divergent/transform)? 2H. What is the range of depths of earthquakes? Is there a pattern to the depth of earthquakes relative to the plate boundary? Part 3. Volcanoes and Plate Tectonics Go to the Smithsonian Global Volcanism Program website ( https://volcano.si.edu/ ). On the “New Activity/Highlights” panel on the right side of the page, select “Current Eruptions”. 3A. What is the “Review Date” for this list of eruptions? 3B. How many “Current Eruptions were bei ng tracked as of this review date? 3C. What is the largest “Volcanic Explosivity Index” (VEI) for the volcanic activity on this list? 3D. How would a volcano with the maximum VEI on this list compare to other “Large” volcanoes in history?(see figure 4 below) Figure 4. Depth and Magnitude of earthquakes in USGS Earthquake KMZ Nazca Plate/South American Plate - Ocean/Continent Earthquake depths vary from shallow to intermediate, mainly between 70 and 300 kilometers, which reflects the behavior of subduction zones. Overriding continental plates have deeper earthquakes, whereas subducting oceanic plates experience intermediate-depth earthquakes. Divergent 0-33 km / Because of diverging plate boundaries, shallow earthquakes mostly occur in the top crust of Iceland, with shallow to mid-crustal areas seeing the greatest amount of seismic activity. Ocean/Continent convergent plate boundary 0-33 km to 500-800 km This region's earthquake depth pattern is indicative of subduction zones, with complicated stress and deformation inside the subduction zone influencing shallow, intermediate, and deep earthquakes. Transform plate boundary 0-33 km / Because of complex plate interactions and regional geology, earthquake depths in strike-slip fault zones can vary, usually including shallow and moderate-depth quakes. 46 volcanoes were in continuing eruption 4 11 October 2023 A VEI 4 volcano is considered a "moderate" eruption, with significant local and regional impacts but not as powerful as larger events.

Go back to the list of “Current Eruptions” and click on the “Volcano” link for one of the highest “VEI” volcanoes (the volcano link is the Orange name on the left side of the table that will take you to the website for this volcano). Click on the “General Information” tab on this page. 3E. What is the name, volcanic type(s), rock types, and tectonic setting for this volcano? Download the “Google Earth Placemark with Features” for this Volcano (the link for this is just below the picture at the top of the Volcano page). Open this in Google Earth, along with the “plate boundaries.kmz” file. 3F. Is this volcano associated with a tectonic plate boundary (within 250 km)? If so, what type? 3G. Do there appear to be nearby earthquakes that might be associated with this volcano? Select Volcanoes The following questions use the “Select Volcanoes.kmz” as well as the “plate boundaries.kmz” and USGS_Earthquakes_6mo_20231012.kml files used in Part 2 of this assignment. “Select Volcanoes” is a selection of Holocene volcanoes from Smithsonian site (Holocene: <3 Ma to present). In the “Select Volcanoes” file there are 6 folders with different regions volcanoes. Double Click on these folders to view these sets of volcanoes. Answer the following questions for each of the sets of volcanoes (figure 6.37 in your textbook and the video: https://goo.gl/PSN9hc may help answer some of these questions.) • type of tectonic boundary (convergent, divergent, transform) • the names of the plates colliding (see table 1 and figure 3 above) • the types of crust (oceanic-continental) that are involved (may be more than 1). • Bonus: indicate what “type” of volcano (shield, composite, lava dome) is most common in these sets (see figure 6.13 in your textbook. https://goo.gl/awPZir ). 3H. South America: 3I. Iceland 3J. Africa Rift Valley (central) 3K. Africa Rift Valley (eastern) - No Answers need here. This was a divergent plate boundary in the recent past, but it has stopped. However, you can still see some tectonic activity in this region. 3L. Alaska 3M. Azores Figure 3. Volcanic Explosivity Index (VEI) Compare. Note that VEI 0 -1 events occur daily where VEI 7 events occur every 100 years or more (source: USGS). A VEI 8 event may occur every ~50,000 years. Semeru/ Stratovolcano, Pyroclastic cone, Fissure vent/ Andesite, Basaltic Andesite, Basalt, Picro-Basalt/ Subduction zone, continental crust yes/ convergent plate boundary no convergent/ Nazca-South American/Oceanic, Continental/ Composite, Shield Divergent, Transform/ Eurasian-North American/ Oceanic, Continental/ Shield Divergent/ African-Arabian/ Continental/ Shield Convergent/ Pacific-North American/ Oceanic, Continental/ Composite Divergent/ Eurasian-North American/ Oceanic/ Shield