Unique Characteristics of Transform Faults There are many characteristics that make earthquakes along transform fault different from subduction zones, rift zones, and mid-ocean ridge transform faults. For instance, transforms faults are when two plates move past each other, shearing, with no creation or destruction of lithosphere. At transform faults, earthquakes are shallow and run as deep as 25 km. the magnitude of the earthquakes are smaller than 8.5 in the scale of Richter. In extensional boundaries, earthquakes are also shallow, but they occur only along the alignment of spreading and are smaller than 8 in magnitude. At compressional boundaries, earthquakes can be found at or near surface and at several hundred kilometers in depth. Because of the difference in temperature, the subducting plate is colder than the plate in which it is being subducted under, the rock begins to warm up and it tends to become brittle enough to break suddenly and cause earthquakes. Here, in the subduction zone, the deepest earthquakes occur to a depth of about 700 km. Continental transform plate boundaries appear today in the circum-Pacific region (California, southern Alaska, New Zealand, and in the Alpine fold belt, e.g. Turkey, and the Dead Sea) (Windley, 1978). Transform faults that originate in continental plate boundaries manifest specific expressions in their morphology and topography over extended distances. These tectonic features are generally associated with complex systems of echelon fractures, folding, and faulting that originate in narrow-elongated zones. In transform fault systems, the deformations that characterize them are mostly oblique divergence or convergence, hardly resulting in evenly distributed shear zones. The resulting ... ... middle of paper ... ... observed to be about 30 mm/yr. Towards the north, the Pacific Plate is moving to, as well as it is being subducted below the Australian plate. Towards the south, these two plates are moving towards each other, but the Australian Plate is being subucted under the Pacific Plate. The motion of these plates is quite small but rapid, which is regularly accompanied by a series of earthquakes. In the northeast section of the fault, there is a seismic zone where deep earthquakes occur. This occurs where the Pacific Plate is subducted under the Australian Plate. In this area, the boundary between both plates known as the Benioff Zone is located. Shallow earthquakes occur towards the southeast of this seismic zone. On the other hand, towards the south, where the Australian Plate is being subducted, deeper earthquakes occur on the southeast section of the seismic zone (UO).
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)
Earthquakes are a natural part of the Earth’s evolution. Scientific evidence leads many geologists to believe that all of the land on Earth was at one point in time connected. Because of plate tectonic movements or earthquakes, continental drift occurred separating the one massive piece of land in to the seven major continents today. Further evidence supports this theory, starting with the Mid-Atlantic ridge, a large mass of plate tectonics, which are increasing the size of the Atlantic Ocean while shrinking the Pacific. Some scientists believe that the major plate moveme...
Earthquakes are the most powerful and with the largest magnitude of 9 on the Richter scale. The Cascadia Subduction Zone is a bit more complicated than the 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.... ... middle of paper ...
When the plates mash together on a convergent boundary, they can create an earthquake. A place with a convergent boundary is New Zealand. When the plates pull apart, a divergent boundary, they create a hole in the ocean that causes molten lava to rush up and it causes a volcano to form. A place with a divergent boundary is Iceland. With about 130 volcanoes all together, it has the most volcanoes of any country in the world and is on two tectonic plates. Santorini is currently in an area of earth where the African and Eurasian plate meet, and Atlantis disappeared with a rumble that could have come from a volcano or an
The San Andreas Fault Line, first identified in 1895 by Professor Andrew Lawson of UC Berkeley, is an 800-mile fracture in the Earth’s surface, stretching from the Gulf of California to San Francisco, and is one of the longest faults in the world. It forms the boundary between the Pacific Plate and the North American Plate, with a complex network of smaller faults branching off the main San Andreas line which are responsible for a majority of the areas earthquakes.
From studying the science behind the San Francisco earthquake, scientists have made a number of important discoveries involving how earthquakes function. At 5:12 on a fateful April morning in 1906, the mammoth Pacific and North American plates sheared each other at an incredible twenty-one feet along the San Andreas fault, surpassing the annual average of two inches (“San Francisco Earthquake of 1906”) (“The Great 1906 Earthquake and Fires”). A few seconds later, the destructive earthquake occurred. The ground shifted at almost five feet per second, and the shaking could be felt all the way from southern Oregon to southern Los Angeles to central Nevada (“Quick”) (“The Great 1906 San Francisco Earthquake”). In fact, the earthquake could be registered in a seismograph on Capetown, South Africa, an astounding 10,236 miles away...
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...
First you might need to know definition of tectonics. It is a theory in geology. The lithosphere of the Earth is divided into a small number of plates which float on and travel independently over the mantle and much of the Earth’s seismic activity occurs at the boundaries of these plates. That is the official definition of Plate tectonics. secondly, this plate covers many parts of continents. plate boundaries don’t go according to Continents boundaries, they make their own boundaries. The North American plat...
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)
The plate tectonic theory is a theory that geologists use to help explain the Earth’s surface processes and events. It explains that the sliding of these plates are either away from each other, sliding past each other, or sliding into each other and causing one of the plates to slide beneath the other. There are three kinds of plate tectonic boundaries: divergent, convergent, and transform plate boundaries. A divergent boundary occurs when two tectonic plates move away from each other. Magma then flows up from the mantle to fill in the space between the plates, forming a raised ridge called a mid-ocean ridge. The magma also spreads in the exterior, forming new ocean floor and new oceanic crust. A convergent boundary occurs when two plates
The Tohoku earthquake caused by the movement of the Pacific plate slides underneath the Eurasia plate at the rate of three inches per year, associated with Japan Trench
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...
The Pacific plate is moving northwest in relation to the North American plate, and it is believed that the total displacement along the fault since its formation more than 30 million years ago has been about 350 mi. Movement along the fault causes earthquakes; several thousand occur annually
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).