Geology Program
Geologically Diverse Area
The southern Oregon region provides a wealth of geologic features such as sedimentary rocks, plutonic intrusions, metamorphism, glacial erosion, and volcanism. In addition to studies of these local phenomena, extended field trips have been made to the Grand Canyon, Death Valley, and the Mojave Desert. Students also participate in the student run geology club, which is involved in a variety of field trips and seminar activities.
Earthquake Information
The newly installed seismograph at SOU is connected to the Pacific Northwest Seismograph Network. Just click on the link for the 12-hour period of interest under the subheading: SOUA. The data is updated every 5 minutes. The array of seismographs within this network is used to identify the location and magnitude of earthquakes in the Cascadian Subduction Zone within a few minutes of the event. The data from this array is used to issue an early warning to people in cities and on beaches along the Oregon coast for a potential tsunami from an offshore earthquake.
Soon after the installation of the seismograph was complete, it received its first "test" as it recorded the magnitude 7.2 earthquake off the coast of northern California on June 15, 2005. Within minutes, data from the SOU seismograph as well as others in the array were used to generate a tsunami warning, resulting in the evacuation of Oregon and northern California coastal areas. Such tsunami warnings need to be issued immediately after a large magnitude (greater than 6.0) offshore earthquake. After the seismic data from this event were processed, it became clear that the June 15, 2005 earthquake occurred along a fault that moved laterally, thus not creating the vertical movement necessary for a tsunami. The new seismograph at SOU not only recorded this large magnitude event, but also recorded numerous aftershocks, providing seismologists with detailed information about this fault system. Data from the seismograph will also be a significant addition to classroom activities and discussions on earthquakes in geology and environmental studies courses as well as a new research tool for geology students and faculty.
The Cascadian Subduction Zone is a linear tectonic feature just off the coast of Oregon and northern California. At this subduction zone, the Juan de Fuca oceanic plate is moving beneath the North American continental plate, resulting in friction that will inevitably lead to a devastating earthquake and a tsunami. An earthquake of 8 to 9 magnitude resulting from a rupture of the subduction zone fault system from northern California to Washington is estimated to have a recurrence interval of 300 to 500 years. The last tsunami triggered by an earthquake of this magnitude within the Cascadian Subduction Zone occurred in 1700 and was documented as far away as Japan. A tsunami generated by the uplift of part of the seafloor in the Cascadian Subduction Zone could reach parts of the Oregon coastline in as little as 20 minutes, necessitating a tsunami warning system using seismographs.
Crater Lake National Park
Crater Lake is located approximately 90 miles from Ashland and the SOU campus. The caldera holding Crater Lake was formed 7000 years ago when the volcanic cone of Mt. Mazama collapsed. The dark blue lake found in the Cascade mountain range is the second deepest in the Western hemisphere. Dr. Jad D'Allura takes geology students and other interested persons on a field trip to Crater Lake during late September 1999.
For more information, follow the links to:
- Crater Lake Data Clearinghouse, USGS
- National Park Service, Crater Lake
- USGS/Cascade Volcano Observatory, Crater Lake
- Volcano World, Crater Lake
Lava Beds National Monument
The lava Beds National Monument is located approximately 100 miles (2 1/2 hours) East of Ashland and the SOU campus. Volcanic activity spewed forth molten rock and lava creating a rugged landscape. Regional volcanic activity formed cinder cones, shield volcanoes, the caldera of the Medicine Lake Highlands strato volcano, lava tubes, both Aa (rough) and Pahoehoe (smooth) lava, spatter cones, and chimneys.
The skylight (entrance) to Valentine Cave is one of many lava tubes in the monument. Dr. Jad D'Allura takes geology students and other interested persons on a field trip to the lava beds monument during late May most years. More advanced geology students or students seeking a minor in remote sensing have used the lava beds as a field site for a course on remote sensing.
For more information, follow the links to:
- National Park Service, Lava Beds
- USGS/Cascade Volcano Observatory, Medicine Lake Volcano
- Volcano World, Lava Beds
Oregon Caves National Monument
The Oregon Caves are located approximately 100 miles West of Ashland and the SOU campus. Small in size, it is rich in diversity. Below ground is an active marble cave created by natural forces over hundreds of thousands of years in one of the world's most diverse geologic realms. A private concessioner provides tours of the cave for a fee. Above ground where old growth forest harbors a fantastic array of animals and plants found nowhere else. You will discover a land rich in conifers, wildflowers, birds, and amphibians.
For more information, follow the links to:
- Friends of the Oregon Caves
- GORP - Oregon Caves National Monument
- National Park Service, Oregon Caves
- U.S. Show Caves Directory: Oregon
Table Rocks Scenic Area
Located in the Rogue Valley, about 20 miles from SOU, the Table Rocks are remnants of an ancient alkaline trachyandesite lava flow. It was erupted about 7 million years ago from a vent near Lost Creek Reservoir, located about 35 miles to the northeast of SOU. The lava flowed over terrain with variable relief in the ancestral Rogue River Valley, where erosional remnants of the lava flow may still be observed. It spread like a sheet over the northeastern part of the Rogue Valley. Seven million years of erosion has removed all but two remnants of this massive flow which now stands 800 feet above the Valley floor.
For more information, follow the link to:
