Northwest Coast At The Cascadia Subduction Zone example essay topic

Cascadia Subduction Zone Quake (aka "The Big One") Having been a resident of the Northwest for my entire life, I have been quite sheltered from the real threat that earthquakes present. After all, large earthquakes only happen in places like California or Japan, not in the Northwest right? Despite the fact that I now know this to be an incorrect statement; this was my impression before discussing the topic with my brother. He suggested that I research the "Big" earthquake that was due to hit off the west coast of Canada.

After doing some research on the subject I was astonished to find that the scientific community is in relative agreement that a large earthquake will strike the Northwest coast at the Cascadia subduction zone; one that could possibly be the most devastating earthquake in recent history. Here on the west coast we are on a plate edge, but we are also on what is called a subduction zone. A subduction zone is where two plates pass each other by one plate sliding below another. In rare instances the sub ducting plates can become locked and pressure continually builds on the locked plates until eventually the stress is too great and the plate snaps back into place. The end result of which is a massive earthquake capable of destroying thousands of lives. Much of the Northwest coasts infrastructure is not prepared for a quake of this magnitude, especially older buildings such as schools.

Preparation for this potentially catastrophic event should be of the utmost importance to all residents in the Northwest. This particular subduction zone is called the Cascadia subduction zone. For the past 300 years these two plates have been stuck onto each other. The pressure caused by the movement of the plates has caused the North American plate to bow. Every year this plate will bow more and more until one day the North American plate will snap back in to its original form. This will cause one of the biggest earthquakes in known history; however it will not be the first of its kind.

Research suggests that in the past 3,000 years a similar type of earthquake has occurred at least four to five times (Minor and Grant, 1996). It is stated that the last one was in the early 1700's and the best of our knowledge suggests that they occur in roughly 400 year cycles. The problem with this is in the early 1700's there was little more in the Northwest than sparsely populated native tribes and accounts of the devastation are not only inaccurate but hard to find. The only tool we have at our disposal is to compare the data from that of the Cascadia subduction zone to those other similar quakes around the world. In the United States on December 16th 1811, and February 7th 1812, a series of earthquakes shook the ground affecting an area over 1.5 million square miles. These quakes also caused the Mississippi and the Ohio rivers to flow backward for a time being.

Also, on September 1st 1923, a quake known as Kanto occurred in Japan, which destroyed two thirds of Tokyo and killed 140,000 people. In Tangshan China, a mega quake of 7.8 on the Richter scale occurred on July 28th 1976, killing an estimated 240,000 people. However, the most recent quake to occur struck on January 17th 1995, in Kobe Japan, registering a 6.9 on the Richter scale, killing 6,000 people and injuring 35,000. In the twenty second span which this quake shook the earth it destroyed 300 billion dollars worth of infrastructure. In recent years more major earthquakes have occurred in areas such as: Turkey, Taiwan, India, El Salvador, Afghanistan, Iran, China, Alaska, USA, and Mexico.

These quakes losses and damages are only an idea of what we have in store for us here in the Pacific Northwest (PREPP). Since our cities in Oregon, Washington, and Canada have never really experienced an earth quake of such magnitude we could quite possibly experience massive amounts of damage; many of our structures such as schools, and bridges are unprepared for an earthquake this size. One statistic I found said that forty five percent of Vancouver schools would collapse because the structures are so old and not earthquake efficient. However damage from the shaking of the quake itself is not the only issue, tidal waves known as tsunamis would ravage the coastline. Tsunamis are hundreds of miles long and can reach speeds in excess of 500 miles per hour, usually traveling about one foot high while still in the depths of the ocean and are very hard to see. It is when they approach land that the trouble begins.

The bottom of the tsunami is slowed down by the debris and sand in the shallow ocean floor. The top of the tsunami continues to travel at the same rate of 500 miles per hour, and can create a wall of 30 feet or more high of water. A tsunami is a possibility in the up coming future, and is likely to happen when the big one hits (Leeman, 1998). In preparation for this catastrophic event Northwest cities need to research and commit funds to increasing the survivability of infrastructure during a massive earthquake. Keeping the infrastructure standing saves human lives, pure and simple, and it is mainly the older buildings that need work. The danger of the Cascadia subduction zone is imminent; most scientists expect an earthquake to occur within the next 100 years.

All that can be done needs to be done to prevent unnecessary loss of life during an event that has been predicted. We can not stop the earthquake, but we can re-tool and re-vamp and educate about earthquakes to be as prepared as possible for the worst to come.

Bibliography

Castell, Gram. "Earth Quake Facts". Pacific Rim Earthquake Preparedness Program Ltd (PREPP). Aug 15 (2003).
web. Leeman, William P. "Cascadia (Pacific Northwest) Seismicity". 1 Oct 1998.
web. Minor, Rick and, Wendy C. Grant. "Earthquake-Induced Subsidence and Burial of Late Holocene Archaeological Sites, Northern Oregon Coat". American Antiquity. Oct (1996).
Aug 15 (2003).