Mt. St. Helens and the Volcanic Cascades Presentation Study Guide

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This project was made possible through the Institute of Museum and Library Services National Leadership Grant for Museum and Library Collaboration

This study guide was made possible through a National Leadership Grant awarded by the Institute of Museum and Library Services. From 2003 to 2006 the University of Oregon Museum of Natural and Cultural History and Univer- sity Libraries digitally archived nine presentations of Oregon’s sights and sounds onto DVD format. Local archivist and former University of Oregon Audiovisual Center director, Don L. Hunter, created the original presentations.

For more information about this archive project please visit our website: http://natural-history.uoregon.edu/Pages/projects.html

The project involves two distinct, but connected, elements: 1) the digital archiving of dynamic slide presentations, and 2) the development of educational curriculum and outreach. Since these two elements are infrequently connected in a traditional archive project, a distinctive approach has been explored to properly present historical texts in a current and evolving educational forum. The approach is two-fold:

1. To present the instructor with materials that can either work dependently or independently with the DVD presentations. Materials created include study guides and activities for each presentation topic. 2. To present the archived materials in a historically critical format. For this second approach we have relied on a critical method that follows these guidelines: a. When dealing with first hand accounts the closer to the original source the better, b. The context of when and why the account was created is important for examining what that source can offer current studies. The archived presentations have been developed into lesson plans using this critical approach, which both examines the topics covered in the original presentations and how the actual presentations themselves need to be read as historical documents.

THEMES • Volcanism: • Effects of volcanic eruptions on surrounding land • Renewal of life after volcanic eruptions • Rocks formed by volcanic eruptions • Effects of magma and lava flows • Geologically active Northwest • Similarities between geological sites in Oregon and others such as Hawaii and Yellowstone park.

Photograph by Don L. Hunter

Crater Lake Caldera, Oregon Mt. St. Helens, May 18, 1980 1 DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 DRAFT VERSION 03/08/06 - DRAFT VERSION 03/0806 - DRAFT VERSION 03/08/06

BACKGROUND Over the last part of the 20th-century and through the beginning of the 21st-century Mt. St. Helens has been the most active volcano in the Cas- cades. In 1980, Mt. St. Helens spewed out smoke, gas, and ash for weeks,

then finally erupted “like an atomic bomb” on May 18, 1980. Like all Photograph by Don L. Hunter volcanic eruptions, the landscape of the surrounding area was suddenly and drastically changed. The landscape was covered in ash and mud, with much of the area’s forest destroyed.

Another dynamic example of a volcanic eruption occurred over 7,500 years ago when Mt. Mazama erupted with such force that it created what is now Crater Lake. The ash distributed by the Mt. Mazama eruption not Mt. St. Helens, May 18, 1980 only changed the environment, but also created a stratigraphic marker (a layer of ash, now buried beneath the surface) that has assisted archaeologists with dating artifacts and human cultures in Central and Eastern Oregon. Both eruptions highlight that the aftermath of a volcanic eruption is both devastating and phenomenal. Volcanic eruptions can produce lava flows and lava tubes; lava flows that surround trees may create lava cast forests. Explosive eruptions can eject volcanic bombs and rapidly deposit thick sequences of ash, killing plants and animals in the destruction path, but preserving evidence of such life in ash fossil beds. The Northwest is the most geologically active portion of the North American continent, and any one of many mountains in the volcanic Cascades could erupt violently like Mt. St. Helens, or produce more quiescent lava flows.

DVD CHAPTERS 1. Introduction (00:00 - 01:23) 2. Chronicling Mt. St. Helens Volcanic Activity (01:24 – 03:50) 3. May 18, 1980 (03:51 – 06:41) 4. Volcanic Activity in the Cascades (06:42 – 11:18) 5. Archaeological Connections and History (11:19 – 13:14) 6. Geological Connections and History (13:15 – 19:30) 7. Geological Features of Volcanic Activity (19:30 – 23:31) 8. Geological Dynamics and the Future (23:32 – 28:30)

SUGGESTED ACTIVITIES • Effects of a Volcanic Eruption Activity—Have students research and present on a real or a fictional volcanic eruption’s effects on a city or town. • Arrange a visit to the Museum of Natural and Cultural History in Eugene, Oregon to take a tour and have students participate in a volcanic rock identification activity. • Find out which Cascade mountain could be the next to explode. Why? • Make your own volcano. Build a mountain complete with trees, houses, streams, etc. Pour baking soda and vinegar into the opening to make the volcano explode. Trace and document the “lava” path of destruction. • Does your city have a plan if a nearby mountain erupts? If so, find out what it is. If not, find out why not. • Research the eruption of Mt. Mazama. What effects did it have on its local area? What effects did it have on other parts of Oregon? North America? • Create group (5 to 10 students) skits portraying a historical volcanic eruption. • Arrange a visit to the Mt. St. Helens Visitor Center at Silver Lake, Washington. 2 DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 TERMS

PLACES:

• Cascade Mountains: Mt. Baker, Mt. Rainier, Mt. Adams,

Mt. St. Helens, Mt. Hood, Mt. Jefferson, Mt. Washing- olcano Observatory ton, Belnap Crater, Little Belnap, The Three Sisters, V Broken Top, Mt. Bachelor, Newberry Crater, Crater Lake (Mt. Mazama), Mt. Scott, Mt. McGloughlin (Mt. Pitt), Mt. Shasta, Shastina, and Lassen • Fort Rock Cave • Lava Cast Forest • Post Office Cave • Valentines Cave • Devil’s Rock Pile

Image courtesy of USGS/Cascades • Ape Cave • Lava Butte

Photographs by Don L. Hunter

Middle Sister (The Three Sisters) Broken Top Mt. Jefferson John Day Fossil Beds: The John Day Fossil Beds National Monument, located in central Oregon, is an area of partially eroded volcanic deposits. The park includes a total of 14,000 acres, which have been divided into three separate areas (Sheep Rock Unit, Painted Hills Unit, and Clarno Unit. Over 40 million years of the Cenozoic Era (65 million years to present) are represented in the volcanic sequences from ancestral Cascade Range volcanoes to the west found at the fossil beds. Numerous species of fossil plants, mammals, and reptiles have been discovered in the deposits.

Painted Hills: An area of vividly colored red, black, and tan striped hills in the John Day Fossil Beds. The hills are largely composed of claystone, much of which is decomposed volcanic ash formed into bands of color created by various metal oxides. The color variation also reflects changes in ancient soils and vegetation during a major global cooling event approximately 33 million years ago. WASHINGTON

Columbia River

Pacific Ocean OREGON John Day River John Day Fossil Beds 3 DRAFT VERSION 03/08/05 - DRAFT VERSION 03/08/05 - DRAFT VERSION 03/08/06 DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 VOLCANIC TERMS:

Accretionary Lapilli “Ash Hailstones”: Lava Flow Crater Lava Flow A term used to describe cemented balls of ash formed by accumulation of ash particles around a wet center (e.g. rain- Cone drop). Main Vent

Ash: Fine material (less than 1/10 an inch in diameter) ejected in an explosive Ash and Lava Layers (strata)

volcanic eruption, which can contain Ash and Lava Layers (strata) volcanic glass, crystals, and pulverized rock from the walls of the volcanic Lithosphere conduit. (the outermost solid layer of the Earth's crust and mantle) Magma Chamber Cinder cone: A conical hill of volcanic fragments that accumulate around and downwind from a vent (the opening at the earth’s surface through which volcanic material passes).

Volcanic plug (called a core plug in the film): Solidified lava preserved in the conduit of a volcano after activity ceases.

Dike: A tabular (shaped like a book) magma body.

Fault: A crack or fracture in the earth, along which tectonic plate movement has taken place. Fault motion can generate earthquakes and can open pathways allowing magma to rise to the surface.

Hot spring: A place where ground water flows onto the surface at high temperature. Such heat may come from a magmatic source beneath earth’s surface.

Lapilli: Material (1/10 – 16 inches diameter) ejected in an explosive volcanic eruption, which can contain volcanic glass, crystals, and pulverized rocks from the walls of the volcanic conduit.

Lava: Molten material that has come to the surface of the earth, containing melt, +/- bubbles, +/- crystals.

Lave tube: A hollow tube in a lava flow formed by drainage of lava after formation of a solid surface crust.

Magma: Molten material under the surface of the earth, con-

taining melt, +/- bubbles, +/- crystals. Photograph by Don L. Hunter

Obsidian: A natural volcanic glass that is formed from Lava Tube, Lava Cast Forest, Oregon quickly-cooling lava, usually of rhyolitic (high silica) composition. It is commonly gray, black, brown, or semitransparent and its fractures are seashell-like in that they form conchoidal patterns.

DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 4 DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 Terms continued Pumice: A low-density, bubble-rich volcanic rock, usually of rhyolitic (high silica) composition. Pumice is commonly light colored and looks like a sponge. Pumice forms from sticky magma during explosive eruptions.

Volcanic bomb: Coarse material (>16 inches diameter) ejected in an explosive volcanic eruption. Bombs are still molten while traveling through the air, therefore bomb shapes vary widely, but are often rounded or elongate.

(Volcanic term definitions modified from American Geophysical Institute Glossary of Geology.)

Mt. St. Helens May 18, 1980 Tree Damage, Photograph by Don L. Hunter

QUESTIONS FOR CLASS DISCUSSION

1. Why did Mt. St. Helens start spewing ash weeks before the May 18, 1980 eruption instead of erupting all at once? Why did it take so long to erupt with the amount of force seen on May 18? What was going on inside the volcano?

2. What is climatic warming? How do volcanoes effect climatic warming? How do volcanoes effect climatic cooling? How do climatic changes effect human populations? How did the eruption of Mt. Mazama affect the natives at the time?

3. What is the significance of volcanic bombs? What other rocks are created by volcanoes? How are these rocks created?

4. At the end of the presentation, the narrator said that we should live in harmony with nature and preserve its pristine beauty. How can we accomplish this?

5. How does nature enrich your life? How does knowledge of the natural world enrich your life?

6. How are you and your community affected by short-term environmental changes (e.g. volcanic eruptions) and long-term environmental changes (the movement of the Earth’s crust)? DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 - DRAFT VERSION 03/08/06 5 DRAFT VERSION 03/08/05 - DRAFT VERSION 03/08/05 - DRAFT VERSION 03/08/05 Sample Selected Standards Category Grade (from Oregon Department of Education) Level 1. Describe the Earth’s structure and how it changes over time. Earth 8 Science 2. Explain the rock cycle in terms of constructive (crustal deformation, Earth volcanic eruption, and sediment deposition) and destructive (weathering 8 and erosion) forces in land formation. Science Earth 3. Use rock sequences and fossil evidence to determine geologic history. 10 Science 4. Describe how earthquakes, volcanic eruptions, mountain building, and Earth 10 continental movements result from slow plate motions. Science

5. Identify how volcanic eruptions and impacts of huge rocks from space Earth can cause widespread effects on climate. Science 10

6. Distinguish between cause and effect relationships and events that Historical 8 happen or occur over time Skills State and 7. Understand how various groups of people were affected by events and Local 8 developments in Oregon state history. History 8. Predict how changes in an ecosystem (not caused by human activity) Geography 8 might influence human activity.

9. Identify and give examples of changes in a physical environment, and Geography 8, 10 evaluate their impact on human activity in the environment.

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