Where do earthquakes occur in the us – In a historical record of earthquakes in the 20th century until the 21th century is now often happens that a large magnitude earthquakes and even less likely that caused the tsunami. As well as recently happened, namely the earthquake in Japan March 11, 2011 scale 9.0 on the Richter scale that were previously revised from the 8.9 SR. The earthquake in Japan has also caused a wave of tsunami japan 2011 . Date October 26, 2010 earthquake in Mentawai scale of 7.2 SR also cause Tsunami Mentawai .
Besides earthquakes that does not lose the enormity of the case in Aceh on 26 December 2004. A powerful earthquake measuring 9.0 on the Richter scale rocked Aceh and North Sumatra as well cause a tsunami in the Indian Ocean. This natural disaster has claimed over 220,000 lives ( List Earthquake / Tsunami in Ages 20-21 ). Of the many earthquakes that occurred in the Century 20-21, on this occasion will little about the understanding of earthquakes , types of earthquakes as well as the factors that cause earthquakes, as reported.
Earthquakes are vibrations or shocks that occur in the Earth’s surface. Earthquakes are caused by movements in the earth’s crust (tectonic plates). The word earthquake is also used to indicate the origin of the earthquake occurrence. Our Earth is solid though, always moving, and earthquakes occur when pressure happens because the movement was already too big to be detained
Types of Earthquake
1. Earthquakes volcanic (Volcano);
This earthquake occurred as a result of magma activity, which usually happens before the volcano erupted. If the higher activeness it will cause an explosion that would also lead to the occurrence of earthquakes. The earthquake was only felt around the volcano.
2. Tectonic earthquakes;
The earthquake was caused by the tectonic activity, ie shifting tectonic plates suddenly has the power from very small to very large. This earthquake caused more damage or natural disasters on earth, a powerful earthquake vibrations capable of spreading to all parts of the earth.
Tectonic earthquakes are caused by perlepasan [power] that occur due to shifting tectonic plates plate like a rubber band is stretched and released suddenly. Power generated by the pressure between the rocks known as tectonic disability. The theory of plate tectonic (plate tectonics) explains that the earth is composed of several layers of rock, most of the area of the crust it will drift and float in layers like snow. These layers stir slowly so broken to pieces and collide with each other. This has led to a tectonic earthquake.
Map of the distribution follows the pattern and special rules and narrow, which follows the pattern of meeting tectonic plates that make up the earth’s crust. In the earth sciences (geology), the theoretical framework of plate tectonics is a postulate to explain the phenomenon of tectonic earthquake that hit virtually the entire area, which is adjacent to the boundary of tectonic plates meeting. Examples of volcanic earthquakes is as happened in Yogyakarta, Indonesia on Saturday, May 27, 2006 early morning, at 5:54 pm.
1. Earthquake collision ; The earthquake was caused by a meteor or asteroid that fell to Earth, types of earthquakes are rare
2. earthquake debris ; Earthquakes usually occur in the limestone area or in mining regions, this earthquake is rare and localized.
3. Earthquakes artificial ; Artificial earthquake was an earthquake caused by the activities of humans, such as the detonation of dynamite, nuclear or hammers that struck the earth’s surface.
The cause of occurrence of earthquakes
Most earthquakes resulting from the release of energy produced by pressure exerted by the plates are moving. The longer the pressure that the growing and eventually reach the situation where the pressure can not be detained again by the outskirts of the slab. That’s when an earthquake will occur.
Earthquakes usually happen at the aforementioned borders of those continental shelf. The most severe earthquakes typically occur at plate boundaries compressional and translational. The earthquake focus in would likely occur because of material sandwiched into the lithospheric layer undergoes a phase transition at a depth of more than 600 km.
Several other earthquakes can also occur due to movement of magma inside the volcano. Earthquakes like it could be a symptom of impending volcanic eruption. Several earthquakes (rare but) also occur due to accumulated huge mass of water behind the dam, such as the Caribbean Dam in Zambia, Africa.
Some (infrequently) can also occur due to injection or akstraksi liquid from / into the earth (eg. At some thermal power plants of the earth and in the Rocky Mountain Arsenal. Recently, earthquakes can also occur from blasting explosives. It can make scientists monitoring the secret tests of nuclear weapons by the government. the earthquake that caused by humans as it is also called induced seismicity.