This animation shows the three-dimensional views of the Cascadia subduction zone. The Juan de Fuca Plate is created at the Juan de Fuca Ridge, then subducts beneath the Pacific Northwest portion of the North American Plate. The location of earthquakes, generation of magma, upward migration of magma, and eruption of Cascade volcanoes are illustrated.
This PDF provides a brief (12 page) introduction to regional plate tectonics, earthquakes, and volcanoes of the Pacific Northwest. The focus is mainly on the subduction zone (coast to Cascade Mountains) because that is where most of the earthquakes and volcanoes occur, and where tsunamis can be generated. This information was gathered and repurposed by Jenda Johnson and Bob Butler from the Pacific Northwest Seismograph Network (www.pnsn.org/), the U.S. Geological Survey (www.usgs.gov), and from two books: Orphan Tsunami of 1700, by Brian Awtater and others, and At Risk: Earthquakes and Tsunamis on the West Coast by John Clague and others.
The morning hike up Kautz Creek to examine debris flows.
Pat Pringle (Centralia Community College) was our expert guide on the Mt Rainier Rainier field trip.
Following the volcano evacuation route away from Orting High School.
Enjoying the sun while discussing the debris flow along the Nisqually River Valley.
Upper Nisqually River Valley leading to the Nisqually glacier at its headwaters.
Field trippers catching up on much needed rest after long day in the field.
TOTLEy hot field trippers enduring 100°F temperatures at field sites along the White River on north side of Mt Rainier.
Pat Pringle (Centralia Community College) describing volcanic mud and debris flows deposited north of Mt Rainier.
Volcaniclastic deposits exposed in the White River Canyon.
Roger Groom demonstrates how to set up the Jello volcano model.
“Igneous” dikes and flows resulting from injecting the Jello volcano with chocolate syrup and assorted concoctions.
Bonnie Magura demonstrates the lava flow viscosity classroom demonstration.
August 14, 2005
Profile of Newberry Caldera showing the gentle slopes of this shield volcano.
David Gilbert, Gene Ramberg, and Edith Adam-Howard examine basalt flow that form rimrock above Prineville.
Folds and faults within Cretaceous sedimentary layers exposed in roadcut on Hwy 26 at Ochoco Summit.
Sediments and paleosols within the John Day Formation.
Photo by Ellen Bishop (Oregon Paleolands Institute).
Roger Groom (Mt Tabor Middle School, Portland) getting up close and personal with the blueschist at Meyer’s Canyon near Mitchell.
Becca Wagner (Sunnyside Environmental School) with a prized sample of blueschist.
August 12, 2005
David Gilbert and Wendy Archibald take a close look at pumice fragments in the Bend Pumice.
Dark Columbia Canal tuff filling a channel within the underlying lighter colored Tumalo Tuff. A mapping exercise on an outcrop smaller than a soccer field.
Broken Top. A stratovolcano east of the Three Sisters that has been dissected by glaciers to expose lava flows on its flank.
August 11, 2005
On Paulina Peak. Karen Shay (top), Edith Adam-Howard (left), Beth Biagini (right), and Adam Joy (bottom) with central Cascade peaks in background.
Swirled and twirled texture of the Big Obsidian Flow within Newberry Caldera.
Rick Conrey explaining the “Three Vs” (viscosity, volatiles, and volume) and “Two Es” (eruption and erosion) of volcanology while TOTLE teachers enjoy the discussion and views from Paulina Peak.
Bob Butler (University of Portland) attempting to serve as “The Sound Guy” for Ellen Bishop (Oregon Paleolands Institute). We captured actitivites at many workshop field sites on video.
August 10, 2005
At White River on south flank of Mt Hood. Rick Conrey (Washington State University) explains recent volcanic history of Mt Hood by labeling features on large photographs of the mountain.
Crater rock on the upper part of the south flank of Mt Hood is a lava dome that grew and collapsed during two volcanic episodes of the last 1500 years. The latest volcanic activity occurred in ~1795 about ten years prior to the arrival of Lewis and Clarks’ Corps of Discovery in Oregon. That volcanic activity produced debris flows and volcanic mud flows (lajars) in the Zigzag and Sandy rivers.
The White River continues to transport volcanic material south from Mt Hood into the Deschutes River. The Sandy River transports similar volcanic silt, sand, and gravel from the southwest flank of Mt Hood into the Columbia River. When William Clark stepped from his canoe onto the delta of the Sandy River in October of 1805, he sank to his knees and named the river the “Quicksand River”.
PowerPoint presentations introducing fundamental concepts and observations of Plate Tectonics and Earthquakes. May be used either as learning aids for teachers of Earth Science or edited by Earth Science teachers for classroom use. Note: When using the PowerPoint slides as a learning resource, it is important to read the notes that accompany each slide. These notes appear below the slide in PowerPoint “Normal View”.