A New College in Orting? Risk Report and Recommendation by: Safe Schools Kause Everyone Deserves (SSKED) 2017
Geographic location and physical site of Orting The city of Orting is located in Pierce county, Washington, about 43 miles south of Seattle. Orting sits in the foothills of Mt. Rainier, between the Carbon and the Puyallup rivers. It is at an elevation of 190 ft (58m). The town is built upon many layers of old lahar deposits. Western Washingon Above: the view of Mt. Rainier from town. Below: Orting from above.
Subduction and the Cascades Subduction: Two tectonic plates are colliding. Generally, whichever has the higher density ( weighs more ) goes under (subducts) the lighter plate. The Cascades (Mt. Baker, Mt. St. Helens, ) The plates going down into the subduction zone are not melting due to its physical properties. As a result of the subducting plate not melting, the fluids between the two plates are basically stuck. These fluids (which include water) cause the mantle to melt into magma. This magma is what causes ERUPTIONS that create the Cascade mountains! https://www.wired.com/2015/05/volcanoes-cascades-quiet-lately/
A brief volcanic history of Mt. Rainer Steam Last lava flow = 2,200 yrs ago (predicted to be less than half a percent of the lifespan of the volcano) Last pyroclastic flow = 1,100 yrs ago 0.4 km across Has 2 craters not eroded by the summit glaciers = sign of youth Mostly andecite and dacite and erupted big amounts of pumice throughout history
Potential Hazards of Mt. Rainier Landslides: large masses of wet or dry rock and soil that fall, slide, or flow very rapidly under the force of gravity. They originate as massive rock falls or avalanches WHY do they occur? Magma releases volcanic gases that partially dissolve in groundwater, that creates a hot acidic hydrothermal system that weakens rock by altering minerals to clay They could transform into lahars (destructive mudflow) that can travel as much as 200 kms Destroys anything in its path
Tephra/Ash Volcanic Gas Released from the magma, majority of it is water vapor Carbon dioxide(180 to 440 million tonnes released a year) Climate Change All explosive eruptions generate tephra (fragments of rock) and become blocks and bombs Smaller fragments are called ash which is deposited long distances from the eruption site The conversion of sulfur dioxide to sulfuric acid which condenses rapidly in the stratosphere to form fine sulfate aerosols This cools the climate and depletes the Earth s ozone layer Pyroclastic flows Contain hot lava blocks, pumice, ash and volcanic gas Lower basal flow of coarse materials along the ground Turbulent cloud of ash that rises above basal flow Destroys everything in its path
Mount Rainier hazard zone
The specific risks to the town of Orting The biggest risk to the town of Orting is Mt. Rainier itself with specific risk factors for a volcanic explosion and associated lahar mudflows (mudslides) Although there are many different forms of mudflows, Lahar mudflows can be some of the most lethal due to their speed. The town of Orting is located on lahar deposits Because of the amount of snow and ice on top of Mt. Rainer and the flow of two major rivers (Carbon and Puyallup) directly towards Orting the risk for a catastrophic lahar flow is high. Other Risks to the town of Orting Earthquakes in the region could soften/liquefy the soil it is situated on. Heavy or prolonged rainfall (same effect as above) Ash Clouds Donald Trump
Should Orting build a new college? Safe Schools Kause Everyone Deserves (SSKED) believes that Orting is not a suitable location for a new college. In the event of an eruption of Mt. Rainier and a subsequent lahar flow, Orting will be devastated and the town will potentially be buried. We do not wish for more people to endanger themselves by moving to such a high-risk location, and we do not wish to invest a large amount of money into an institution that could be destroyed within years.
Our recommendations for Orting Permanent Lahar-Detection Systems 30 minute detection gives people time to get to higher elevation (even only 50 feet up). Although Mt Rainier has a permanent lahar-detection system and public notification system, we believe this is not enough. Creation of 50 ft elevated safe zone Will serve as a meeting place in the case of a lahar flow. Additional evacuation routes New vehicle access routes should be established so that the population of Orting can evacuate in a timely manner in the case of an emergency.
Let s not have this be our future college