Earthquakes are historically one of the most dangerous natural disasters that mankind has ever faced. Until recent times, earthquakes have been just that: natural disasters. Naturally occurring earthquakes are almost entirely found near tectonic plate boundaries, and are generated when subsurface stress is released. However, there has been an alarming increase in occurrences of earthquakes in areas far away from plate boundaries; these areas have historically seen very little earthquake activity. Compelling scientific evidence gathered over the past decade reveals impressive correlations between the epicenters of these non-plate boundary earthquakes and drilling operation locations. The techniques employed by earth resource exploration may …show more content…
If these tectonic plates are moving at different rates relative to one another or are moving in different directions entirely, the rock at the boundaries will experience stress. Eventually the displacement between plates becomes large enough such that the rock under stress will rupture and release energy in the form of an earthquake. Interplate generated earthquakes account for the majority of naturally occurring earthquakes on earth. In less common instances, the stress regime created at plate boundaries can transfer to intraplate regions far away from plate boundaries. An inactive fault plane in such a region could be reactivated and rupture, generating an earthquake potentially far away from a plate boundary. Natural, intraplate earthquakes thus are not entirely uncommon, but do occur much less frequently than interplate earthquakes and are generally weaker in …show more content…
If the shear stress decreases, a fault is more much likely to rupture and cause an earthquake. There are hundreds of wells in Oklahoma which actively inject fluid at high pressures into the earth, and the locations of these wells shows strong correlation to the epicenters of earthquakes. However, this fact is not entirely reliable in showing the causation of earthquakes, since Oklahoma has a high spatial density of wells as it is. The increase of earthquakes in this area alone, however, is evidence enough that something is changing in the subsurface to generate such high seismic activity in
The Long Point Fault is located in Harris County, which covers 83,450 square miles located with in Houston, Teaxas City Limits. Research specifies that there are three sections of the Long Point fault that appear to be active; some sections of the Long Point fault have averaged more than 2 cm per year of vertical offset over the last 20 years. Evidence of the faults concludes it is a natural fault. The reason for activity is not caused by man, even though man’s activities are not helping the issues, but clearly humans are not the initial cause, biological activity can be in fact an adiitional cause for its movement. A brief description of the type of fault and its relationship with the strata and the faults beneath the Houston area, are at depths of 1,000 to 4,000 m. They have been well-defined through the study of well logs and seismic lines. Studies have resuted in assumuptions that some of these subsurface faults penetrate younger sediments at shallower depths, and contain faults that have of set the present land surface to produce recognizable scarps. (Gabrysh)
Tectonic plate movement can occur as close as two and up to 450 miles below the Earth’s surface. According to the Indiana Geological Survey, Indiana’s fault lines are further underground than those in California and Alaska, causing more minor quakes in the Midwest. However, Hoosiers should heed the recent earthquake as a warning for future quakes. Earthquakes can and do happen in Indiana, and almost anywhere else in the world. This is the one natural disaster that people cannot avoid no matter their location on Earth. And, being unprepared can have devastating results.
Earthquakes play a major role into understanding the composition and materials that exist within the Earth (Merali and Skinner, 2009, p.252). Earthquakes are the main source of insight into the inner workings of the earth, due to the nature of the seismic waves they produce. P and S waves are reflected and refracted at different boundaries within the earth, and this enables seismologists to make inferences about the internal composition and structural of planet Earth. (Merali and Skinner, 2009, p.252).
Imagine if a 9.0 earthquake struck the West Coast today, resulting in a giant tsunami. Coastal towns would be washed away or completely isolated, and electricity would be lost (FOX5). There would be $70 billion in damage and people would only have 15 minutest to evacuate or move to higher ground resulting in 10,000 deaths (FOX5). This sounds like a plot for a scary movie, but this is actually a reality. The Oregon Coast in located on a subduction zone, which makes it very susceptible to major earthquakes and tsunamis. With the Cascadia subduction zone running along he West Coast the threat of a major tsunami is very real.
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 the CSZ megathrust fault. It is roughly 1000km long, a dipping fault that stretches from the 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 experience similar quakes in the near future.
Regina:The Early Years. (2014). Cyclone of 1912. Regina: The Early Years 1880 -1950. Retrieved March 7, 2014, from http://scaa.usask.ca/gallery/regina/central/cyclone.html
There are concerns that fracking could be the causation of earthquakes. In areas where fracking operations occur and earthquakes are not the norm, there has been instances of seismic activity. For example, before 2011, the last seismic activity experienced by small town in Ohio named Youngstown was in 1776, but in a span of months during 2011, more than 100 instances of seismic activity ranging from 2.7 to 3.9 on the Ric...
Since record keeping began, sometime in the 18th century, there have been 13 major earthquakes along the San Andreas Fault. However, radiocarbon dating has proved that earthquakes have been happening along the fault for thousands of years. The earliest recorded earthquake happened on July 28, 1769, and was experienced by Spanish explorer Gaspar de Portola while he camped along a small lake he named “San Andreas Lake”. Other notable early earthquakes occurred in 1836, 1838, 1865, 1868, and 1890. Unfortunately, there is no seismographic data recorded for these early earthquakes since it was not until 1887 that seismographs began being used in the United
Hazards pose risk to everyone. Our acceptance of the risks associated with hazards dictates where and how we live. As humans, we accept a certain amount of risk when choosing to live our daily lives. From time to time, a hazard becomes an emergent situation. Tornadoes in the Midwest, hurricanes along the Gulf Coast or earthquakes in California are all hazards that residents in those regions accept and live with. This paper will examine one hazard that caused a disaster requiring a response from emergency management personnel. Specifically, the hazard more closely examined here is an earthquake. With the recent twenty year anniversary covered by many media outlets, the January 17, 1994, Northridge, California earthquake to date is the most expensive earthquake in American history.
benchmark for the future, and integrated investigation into the effects of earthquakes in the U.S.
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)
They are the earth’s crust; they move very slowly every year. As the tectonic plates slide over each other they cause earthquakes. Earthquakes produce various damaging effects this includes damage to structures of buildings, bridges and other standing formations which then...
It was a beautiful day like any other with the clear blue sky and the
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).
Earthquakes occur almost all over the world and often cause many casualties and injuries, but it is a common misconception to think that all earthquakes or even most of them cause destruction. In fact, most earthquakes aren’t even strong enough to be felt by humans and most animals, and can only be recorded by seismometers that are strategically placed in all corners of the world in order to get a reliable and precise reading on the earthquakes strength. Another common misconception about earthquakes is that people believe that the injuries and deaths that result from earthquakes are because of the earth’s shaking itself, whereas it is in fact usually because of heavy items falling from the incessant vibrations. Earthquakes can be defined as