The cause of earthquakes can we learn from the concept that the Earth that we walk on is alayer called the crust. Earth's crust is hard, brittle and easily broken and the "floating" above the rocks are relatively rigid do not often referred to coat. Earth's crust is also broken into10 pieces that we call fractional plates that have been discussed in chapter one, and eachmove. There is that move away from each other, there is that move toward each other so that it can occur any collisions between moving plates and each shift. generally very slow movement of the plates is only few centimeters within 1 year. However, if the movement is jammed and interlocked resulting in the collection of energy that takes placeon an ongoing basis until such time as these rocks are not able to resist this impulse, there will be a release of energy suddenly we call
earthquakes.
Based on the causes, earthquakes can be divided into four main causes, namely the
collapse of the caves in the earth,
man-made earthquake,
volcanic eruption, and
tectonic activity.
A. Volcanic eruptions (Volcanic Earthquake)
At the time
the volcano erupted causing earthquakes often called a
volcanic earthquake.There are 3 causes of volcanic earthquakes. First, there is contiguity between the walls ofvolcanic magma. Second, the gas pressure when the mountain erupted. Third, due to thesudden movement of magma in the magma chamber.
Volcanic earthquakes have a very weak force, that vibrations are usually only felt in the area around the volcano only. However, although small tremors continue to watch given the presence of volcanic earthquakes is usually a sign of the eruption of a volcano. And some of the volcanic eruption there that potentially carry considerable damage especially ifaccompanied by a hot cloud. There are several volcanoes that have the nature of thatexplosive eruption or the eruption of a very powerful, but there are only issued a volcano erupting molten lava.
2. The collapse of Limestone Caves / Regional Mine (rubble earthquake)
When the science of earthquakes has not been developed, experts expect the past
earthquake caused the collapse of the giant caves found in the earth. It turned out afterfurther investigation, the allegations were completely untrue because of the collapse as itdid not exist. If only the collapse, it only happens in the subterranean (under ground),limestone quarrying and the like. However, the fall was only able to cause vibration of the earth that very small and is local (local).
3. Artificial earthquake
There is a human activity that can cause
earthquakes, such as nuclear testing, that cancause vibration waves of earthquakes, earthquake waves may spread in the earth, so it can be recorded by a seismograph. It is currently banned from nuclear testing to be done, somecountries still trying to underground nuclear testing, it became established an international agency to monitor underground nuclear test called the CTBTO (Comprehensive Nuclear-Test-Bantraty Organization) that has stations scattered around the world.
4. Tectonic earthquake
Tectonic earthquake caused a shift in the tectonic plates in the crust layer. It then producesa shift in the tectonic style is then pushed, resulting in the weakest part will break. Thisevent came to be called by the earthquake. The meeting also led to the formation of plateis a row of mountains throughout the meeting, and at the plate can also arise fragments of rock (faults) as a result of the pull and pressure of plate movement-lempengbatuanconstituent of the earth's crust. Nearly 90% of earthquakes caused by tectonic plateactivity.
Process events and track the centers of
tectonic earthquakes around the world can be explained by a theory of the Science Review of Earth (Geology) called Tectonic Plates (Plate Tectonic).
