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Earthquake in Pacific to ravage the US Northwest Coast

By Shelsie Delphin 7/17/2015

Tsunami hitting Japan

     Recently, there have been reports of a possible earthquake with a magnitude of 9.0 that could one day soon, rupture throughout the Pacific Northwest. Fear mongering titles across various news outlets have people concerned about the fate of the western coast. It is described as an earthquake that is "long overdue" by seismologists. Popular news source, The New Yorker, was one of the first media outlets to break the news. The author, Kathryn Schulz reports an alarming account of what is to happen to the Cascadia subduction zone, and how it may cause, as she describes "one of the biggest earthquakes in American history". Most people are familiar with the San Andrea fault lines, and for a while there have been speculations that it would be the one to cause America's most destructive earthquake (There's even a movie about this). However, now it seems there's is some competition! To this point , according to the seismologists interviewed by Schultz, the cascadia subduction zone runs hundreds of miles between Northern California and ends in Vancouver, and under normal conditions, tectonic plates slide under each other, but in this case the plates are jammed up against each other. Eventually causing the fault line to blow, resulting in an ~8.7-9.2 magnitude earthquake, and letting loose a tsunami-like wave (similar to the tsunami that hit japan, but likely to be worse). Experts are saying to expect about 13,000 casualties as the aftermath. Although the Pacific Northwest region of the US is no stranger to earthquakes, there's nothing that can mentally, or physically for that matter(given the lack of time), prepare citizens to what may soon come. To further exacerbate the situation, scientists cannot give an exact date, nor a month, but it is surely happening, as tsunami proxy data(physical evidence of a tsunami, such as eroded rocks and specific sediment formation) suggest a large scale tsunami in the area every 240 years.

But how does something like this happen?

the ring of fire

     With regard to this, let's take it back to basics so that we can have a better idea of what's going on. To start, the Earth has four major layers, the inner core, outer core, mantle and crust. The crust and the top of the mantle make up a thin layer on the surface of the earth. The thin layer is actually fragmented pieces that slide past each other, we refer to these pieces as tectonic plates. Many of these plates lie in the ocean floor, such as our friend the cascadia subduction zone, as seen in the photo to the right. What is more, these plates slowly slide past each other and bump into each other. The edges of the plates are referred as plate boundaries and the plate boundaries are made up of faults (The area where two plates come together). Some edges of the plates are rougher than others, and so they have a large amount of friction and get stuck while the rest of the plate keeps moving. While stuck, the force that would normally produce sliding is actually causing a buildup in energy. Finally, when the sliding force equals the force of friction, the edges slide past one another, releasing a large amount of energy, which is referred to as a seismic wave. These Seismic waves are recorded by seismographs, and the ratio of amplitude(height, like the height of a tsunami) of the wave over some arbitrarily small amplitude is what determines, along with some other constants, it's value on the richter scale. So to say, the strength of an earthquake is determined primarily by the amplitude, or height, of the seismic energy wave it produces. Finally, these seismic waves, being a wave, can cause some really nasty tsunamis(think about when you're in the pool making waves, the waves create more waves). So, what is the take away? Stay way clear of this area until this earthquake passes.

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