Changing Earth lesson 6D Why is the Pacific Northwest a Geological Hotspot?

PART 4 Class Agenda TODAY’s PLAN: Today’s TaSK: EQ: How big can our PNW earthquakes be? LT: “Obtain information” to identify “Patterns of scale, proportion, and quantity” for Cascade volcanoes and related earthquakes. SC: Conduct research using USGS records to draw conclusions about the size and timeline for PNW earthquakes & volcanoes. Group Work

Table discussion: What does this quote mean? “The same geological processes that threaten our lives with earthquakes, tsunamis, and volcanic eruptions also nourish our spirits by creating the spectacular mountains, valleys, and coastlines of the Pacific Northwest.” Mt. St. Helens National Volcanic Monument Olympic National Park

What is the Cascadia Subduction Zone? Why are Washington and Oregon geologists so interested in studying the 2011 Japan quake? https://www.youtube.com/watch?v=e6U198ULMYo

Use “Systems” thinking to “Analyze and Interpret Data” about volcano hazards. Follow this USGS link and select the “CVO” tab. Answer in your lab notebook: What is the date of the report? What is the current volcano alert level? What are some recent observations made? How often are they monitoring the Cascade volcanoes? https://volcanoes.usgs.gov/vhp/updates.html

How can we analyze & interpret data to support the claim, “The Pacific Northwest is a geological hotspot?” We will be conducting an investigation using resources provided by your teacher. The next slides match the questions on your worksheet. FOLLOW THEM IN ORDER! DO NOT SKIP AROUND…

Q1:What type of tectonic plate boundary do we have Q1:What type of tectonic plate boundary do we have? Q2: For such a tiny plate, why is Juan De Fuca so special?

Q3: According to scientists, how did the cascade volcanoes form? Watch this animation to answer question 3

Robert J. Lillie Bernard Garcia Look at this model to identify the mountain range formed as a result of the Juan De Fuca plate “Subducting” under the North American Plate. Circle it on your Pacific Coast map. Parks and Plates ©2005 Robert J. Lillie

Can Earthquakes trigger volcanoes or can volcanoes trigger earthquakes? This is a very common question… What do you think? Discuss with your table partner…

COMPLETE MIDDLE CHECK HOW ARE YOU FEELING ABOUT YOUR SUCCESS CRITERIA? HOW IS YOUR TABLE PARTNER DOING? RAISE YOUR HAND IF YOU HAVE QUESTIONS.

Map - Volcanoes Step 1- Fill in the key Choose a color to represent volcanoes (Pick a dark color like purple or navy) Step 2 – Resource Maps Use all 3 maps to look for volcanoes and draw triangles on your map with your volcanoes color Step 3- Group Comparison Share with your group what you found and why you marked specific areas on your map

The red dotted line represents the start of our historic record of volcano eruptions. Scientists use “Core” samples to look for patterns in deposits of volcanic rocks and ash to determine eruptions prior to 200 years ago. Q4: Based on this graphic, which Washington/Oregon volcano(s) besides Mt. St. Helens would you predict would be most likely to erupt next? Which would be least likely to erupt next? Explain your reasoning.

Go to The Pacific Northwest Seismic Network Go to The Pacific Northwest Seismic Network. click on the links for information about each of the cascade range volcanoes listed below: Mount Adams, Mount Baker, Crater Lake, Glacier Peak, Mount Hood, Mount Rainier, Mount. St. Helens, Three Sisters On the left side of each volcano’s web page is a link for “Latest Earthquakes” located near the volcano. When magma moves under a volcano, it generates small earthquakes. This means the number of earthquakes under a volcano can be used to predict the likelihood of an eruption in the near future. For example… In the months before the 1980 eruption of Mt. St. Helens there were 100s of small earthquakes underneath the volcano.

Analyze the volcano data to interpret and answer: Q5: Based on the most recent earthquakes of the cascade volcanoes, predict which volcano other than Mt. St. Helens will erupt next? Q6: Over the last year, how do the number of earthquakes at your predicted volcano compare to the number of earthquakes at Mt. St. Helens? Does this change your prediction? Why/why not?

Q7: Use the given volcano map for the PNW to locate the closest volcano to us… Q8: According to the data record on it’s webpage at the Pacific Northwest Seismic Network, how often does it erupt? Q9: What is special about the last time it erupted? Q10: Why is this volcano’s eruption associated with flooding?

Mount Rainier: Although considered an “Active Volcano,” our beautiful mountain has not erupted since 1894. What does it mean to be called an “Active” volcano? Large mudflows called “Lahars” can occur without warning, even without a large eruption. What is a “Lahar” mudflow?

Who is in Danger if Mount Rainier Erupts? Look at the “Volcano Debris” (Paper Map 4) to identify the path of Mount Rainier’s “Lahar zone” and “Flooding zone.” Q10: Why do you think Mount Rainier’s eruptions are associated with flooding? Follow the link to view glaciers on Mount Rainier Mount Rainier Glacier Map link Q11: What would cause flooding from a nearby volcanic eruption?

Questions 12-13 Watch the video & answer https://www.youtube.com/watch?v=cDaW-2RWohc Q12: Should the people of the Pacific Northwest be required to prepare for geological disasters? Why/Why not? Q13: How are volcanoes, earthquakes and tsunamis evidence for slow and large scale motion of the Earth’s Plates?

Semester 1: Revised Thoughts (SNB 11) On the top half of the paper write Revised Thoughts for “Rock Cycle, Sink Holes & Soil.” On the bottom half of the page write Revised Thoughts for “Tectonic plates, Earthquakes, Volcanoes, and Tsunamis.” OTHER PAGES REQUIRING REVISED THOUGHTS: 15, 19, 21, 25, 27, 29, 32, 33, 37

EXIT TICKET: “END CHECK” & COMPLETE YOUR MAPPING PROJECT