Monday, February 18, 2013

Living Beneath a Sleeping Giant

The Pacific Northwest is one big conglomeration of geographic landforms and formations.  There is not one distinct form of land form construction.  One of the major and prominent forms of topography is the visible evidence of volcanic and geothermal activity.  Scattered along the Cascade mountain range is a series of dormant volcanoes; some of which are not so dormant. 
View of Pacific Northwest

Cascadia: The series of volcanos along the Cascade range though Oregon and Washington are referred to as Cascadia. The volcanic activity in Cascadia is a product of subduction, where the Juan de Fuca and the North American Plates are meeting.  The Juan de Fuca place is sinking below the North American plate just off the coast of Washington and Oregon.  This creates seismic activity and in turn causes magma to travel to the surface.  Though the likelihood of an eruption occurring in the Cascadia is unlikely, but when an eruption does happen, it is often violent.  There is a lot of seismic activity still accruing in the Pacific Northwest and is in need of monitoring every day. 

Juan de Fuca Subduction Zone Cross Section

Mount St. Helens:  Many of the dormant Volcanos are well known by most.  The most famous is Mount St. Helens.  At 8:32 Sunday morning, May the 18th, 1980, Mt. St. Helens erupted and amazed the world with its devastation and beauty.
Mount St. Helens Eruption

Mount Rainier: But is this the end of volcanic activity in the Pacific Northwest?  That is a matter of opinion.  Mount Rainier is currently being watched by the PNSN because of its constant seismic activity.  On a daily basis there is something occurring seismically from glacier movement to magma flows under the volcanos surface.  Rainier is the tallest mountain in the Cascade Range at 14,410ft above sea level.  But Rainier was once even taller than it is now.  There is evidence that like St. Helens, the edifice of Rainier collapsed during an eruption leaving behind a crater; that has over time rebuilt itself due to many eruptions.

Mount Rainier from Seattle
Hazards Awaits: Mount Rainier is considered to be the most threatening volcano in the Cascade mountain range.  When (not if) the next eruption occurs, the entire Seattle-Tacoma area is in high risk of Lahar and flooding post Lahar.  There is not much we can do to prevent an eruption.  The best that can be done at the moment is continued surveys and studies to remain aware of what is continuing to happen beneath the mountain surface.  

Areas of Impact from Rainier Eruption

Works Cited

Pacific Northwest Seismic Network. 2013. (accessed February 16, 2013).

United States Geological Service. 12 17, 2012. (accessed February 16, 2013).

Wikipedia. February 12, 2013. (accessed February 16, 2013).

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