With the recent earthquakes in California, many are worried about the next earthquake that could be the potential “big” one that many geologists have been predicting for many years. The Cascadia subduction zone is also known as CSZ megathrust fault. It is roughly 1000km long, a dipping fault that stretches from Northern Vancouver Islands to Cape Mendocino California. The zone passes through British Columbia, Washington, Oregon and into California.
The Cascadia region has experienced several types of earthquakes and it is very likely to experienced similar quakes in the near future. Cascadia earthquakes fall into three major categories: The first type is shallow or crustal earthquakes which are caused by rupture of the faults in the North American Plate. The Scott Mills earthquake happened in 1993 and it occurred in the Willamette Valley. The second type is deep or intraplate earthquakes are caused by rupture faults within the subducting Juan de Fuca Plate, deep earthquakes are often the most damaging type of earthquakes. In 2001, a deep earthquake named the Nisqually hit the Puget Sound area of Western Washington. The third type is the Cascadia Subduction Zone earthquakes are the powerful and with the largest magnitude of 9 on the Richter scale. The Cascadia Subduction Zone is a bit more complicated than other two types of earthquakes. The zone separates the Juan de Fuca plates and the North American plate, subduction earthquakes happen when one plate is pushing beneath each other. When one of the faults ruptures, the overriding plate push upward generating frictional stress eventfully the stress reaches a critical point, a sudden failure occurs along the fault plane resulting in the “megathrust” earthquake rel...
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... dunes will hold off the wave that would be coming ashore. There are signs all over the city, and we have been going to Manzanita for over 15 years, our family has never talked about who to do, we don’t know where to go and we don’t have a emergency supply stored in case of any emergencies. I truly believe that the city has to educate their residents and run practices, like fire drills for schools. I think being prepared and educated will save many lives if and when we get the big one in the Cascadia region.
Works Cited
http://www.crew.org/cascadia http://www.crew.org/sites/default/files/cascadia_subduction_scenario_2013.pdf http://www.pnsn.org/outreach/earthquakesources/crustalfaults www.iris.edu/hq/files/programs/education_and_outreach/aotm/5/2.Subduction_Rebound_Background.pdf www.crew.org/sites/default/files/cascadia_subduction_scenario_2013.pdf
Most of Arizona’s earthquakes are associated with the San Andreas fault as most of Arizona’s earthquakes are shocks from epicenters located in California. Arizona has had earthquakes with epicenters located in its borders and just like the ones located near the San Andreas fault, they are linked to a transform plate boundary and are dip-slip earthquakes. Much of the focus of these earthquakes can be centered around the Grand Canyon as much of the after-effects of these earthquakes caused phenomenons to occur in the Grand Canyon. Many rockslides took place in the Grand Canyon and plenty of the cracks found in the canyon’s rock layers are attributed to some of the earthquakes that took place in Arizona since the geologic landscape formed its current
The west coast of the islands is on the edge of a continental shelf created by ancient volcanic movement (Broadhead 5) .This volcanic activity is due to plate tectonic movement which also created the numerous amounts of earthquakes on the island. Compared to the rest of British Columbia, Haida Gwaii has the most earthquake activity (Broadhead 5), the last of which being in a magnitude of 7.7 on t...
The scenario mentioned above was based on the rupture located along the Cascadia fault line. This fault system runs from Northern California to Vancouver Island about 700 miles off the shore (FOX5). Scientists use to believe that the San Andreas Fault was where a large earthquake tsunami would originate, but recently their attention has shifted to the Cascadia subduction zone which is now said to be much more dangerous than previously thought (FOX5). Recent earthquake events have added even more tension and possibility for a large-scale tsunami. On March 10, 2014, a 6.8 magnitude earthquake struck off the coast of Northern California, which put a lot of stress on the Mendocino Triple Junction (Davidson). The Mendocino Triple Junction is where three tectonic plates collide, and is very unstable (Davidson). This junction has all this built up pressure and is about ready to explode. Scientists believe that this junction will be the origin of a tear along the 680-mile long Cascadia Subduction Zone. (Davidson). The disaster that follows will be considered the United State’s largest modern-day earthquake.
The article I have chosen is the one on how “massive Mega-Quake Could Destroy Pacific Northwest”. The author notes that massive quakes have a magnitude of up to 9.2. It could last four minutes, according to seismologists. It occurs and then a wall of water follows. However, it could take up to fifteen minutes later. Individuals need to be concerned about the risks associated with the massive mega quakes. However, it seems that the people in the potential inundation zone have very little knowledge on the risks involved with mega quakes. Individuals that would be given a chance to live in the Pacific Northwest say that they would think twice. There is the need to offer education and training for the residents of the Pacific Northwest on the need for emergency preparedness and the things that should be done in case of massive mega quakes.
Ralph Waldo Emerson once said, “we learn geology the morning after the earthquake.” Fortunately for those living along the San Andreas Fault line in California, there are people behind the scenes, from geologists to city and emergency planners, who have no intention of waiting that long.
It is not foreign for the New Madrid zone to quake. Geologist Martitia Tuttle, who has been investigating the faults says “Some had archaeological sites on top of them with 2,000-year-old artifacts,” Tuttle goes on to say. “There’s no way the New Madrid earthquakes were a one-time freak event.” The Midwest had been slammed by violent quakes around A.D. 1450 and 900 and 2350 B.C.—and probably more often (Rusch). Over the past 4,500 years, the region was most likely visited by multiple quakes of 7.0 or more. Big groups of earthquakes have been discovered, dating back to ancient times.There have been more quakes to hit this region after the 1811-12 disaster, one hit Lepanto, Arkansas, in January 5 of 1843. Another 6.7 quake shook Charleston, Missouri, in October of 1895. So, why are such earthquakes hitting so far from a tectonic plate boundary? Why are they so powerful? Their power comes from the material around the New Madrid zone. The materials in the earth are not accustomed to such shakes, and therefore the rock is not equipped to absorb the shocks of the earthquakes. This is why they were felt in such a wide range of areas. Many theories have been put forth as to what actually sparked these earthquakes in this zone, but none have been fully accepted as true. It has been put forth that a hot spot under the area is to blame, because it is melting the earth’s crust in
One of the worst natural disasters in United States history to this date occurred almost 109 years ago. On April 18, 1906 at 5:15am in San Francisco, California, the earthquake of San Francisco occurred hitting between 7.9 and 8.3M on the Richter scale. The San Andreas Fault, which is about 600 miles long, running from the Gulf of California to Cape Mendocino and is an active strike-slip fault, cut through the continental lithosphere to cause the San Francisco Earthquake of 1906. An earthquake is a trembling or shaking of the ground produced by movements along a fault (Strahler, 2012). After the tension is released at a critical point, the fault or tectonic plate slips and relieves the strain and creates the seismic waves, which radiates out in all directions causing the shaking of the surface.
...larly to Los Angelenos, that disaster could become a reality of Los Angeles if people start ignoring the warning signs that permeate throughout Southern California.
Before examining the Northridge event, understanding the naturally occurring hazard that is an earthquake will help to better understand exactly what happened and why it was such an important geological event. With four distinct layers, two layers, the crust and upper portion of the mantle, compose the skin that is the surface layer of the Earth. The crust is not a single, continuous piece. It is actually several different pieces, or plates, that come together to form the puzzle that comprises the surface of the Earth. These plates are in constant motion rubbing against one another. These areas, known as fault lines, where the plates rub up against one another have spots where one plate ”gets stuck while the rest of the plate keeps moving. When the plate has moved far enough, the edges unstick and is how most of the earthquakes around the world occur” (Wald, 2012). The energy stored from the friction of the two plate...
study of the San Andreas fault system." (USGS) When the 1906 earthquake struck scientist set
Earthquakes have impacted many areas in the United States, especially along the western coast in states like Alaska, Hawaii, and California. California is particularly vulnerable to earthquakes because it is located on the famous San Andreas Fault in the very seismically active Ring of Fire. Earthquake hazards are also prominent in many other regions across the United States including the Rocky Mountain region, the New Madrid Seismic Zone (a portion of the central United States), as well as portions of the eastern seaboard, specifically South Carolina. Close to “75 million people in 39 states” face considerable and recurring risks from contemporary earthquakes (Monahan 2). Owing to the destructive effects of California’s earthquakes in the past few decades and generally around the world, scientists have made an effort to locate and measure the size of an earthquake, predict a location’s vulnerability to earthquakes, and develop seismic warning systems in an attempt to reduce potential losses in...
...cal consequences for survivors of future catastrophes. Communities should have a well prepared plan in dealing with disasters such as Hurricane Ivan. Unfortunately, Hurricane Ivan was the culprit of major damage among many communities, and many lives were lost. Of course there are no fingers to point because it is a force of the earth that caused this tragedy, but every day we are learning of better methods to prepare us for any disaster. It seems like we hear of a major natural storm outbreak almost every month, but every time it seems like we are more prepared. Scientists and engineers have teamed up to ensure that our architecture and safety plans are the best they can be. We're also developing technology that can help us to detect these incidents faster and earlier than before, so we hope that these incidents can be reduced to a minimum in the future.
The epicenter of the earthquake in Alaska was about 10km east of the College Fiord, approximately 90km west of Valdez and 120km east of Anchorage, Alaska largest city. The earthquake was felt about 1,300,000 square kilometers away from the epicenter. (Christensen, Doug PhD.) About 30 kilometers deep, the first slip occurred under northern Prince William Sound, and an 800 kilometer rupture in the rocks extended horizontally, roughly parallel to the Aleutian trench. (Bolt) The cause of this massive earthquake was the vertical displacement of northwest motion of the Pacific plate. Also, it was estimated that about 200,000 square kilometers of the crust were deformed, making this the greatest area of vertical displacement ever measured. (Bolt)
San Andrea Fault Introduction The San Andreas Fault is a geologic fault zone between two tectonic plates that runs from San Francisco south to San Diego in California. It is an area of frequent earthquakes caused by the plates sliding past each other. It is so called because it runs along the San Andreas Valley. The San Andreas fault was brought dramatically to world attention in 1906 when sudden displacement along the fault produced the great San Francisco earthquake and fire. This earthquake was but one of many that have resulted throughout its life of about 15-20 million years.
Earthquakes belong to the class of most disastrous natural hazards. They result in unexpected and tremendous earth movements. These movements results from dissemination of an enormous amount of intense energy in form of seismic waves which are detected by use of seismograms. The impact of earthquakes leaves behind several landmarks including: destruction of property, extensive disruption of services like sewer and water lines, loss of life, and causes instability in both economic and social components of the affected nation (Webcache 2).