Condition-related disasters or Geological Process

Here we review the processes of natural disasters is the primary geological process. Geological processes can be identified as an endogenous process (which works inside the Earth) and exogenous processes (who worked on the surface of the Earth).Endogenous process consists of:

1. Tectonic motion - causing an earthquake. Mengebabkan earthquake fault occurrence in the earth's crust. Earthquake shocks could spark Avalanche or Landslide as happened in Padang Pariaman. The fault that occurred on the seabed could trigger a tsunami (the process occurred at sea or hydrosphere), as happened when the earthquake December 26, 2004 in the Indian Ocean. Meanwhile, the landslide that occurred in the deep ocean trenches can also generate tsunami.
2. Magmatic - raises volcano - causing volcanic eruptions that cause pyroclastic flows or when there is Lava Hot participating crater lake collapsed. Then, deposition of sand on the slopes of the volcano when exposed to heavy rain (atmospheric processes) can lead to Lava flow, either hot or cold lava lava. Examples like that happened Mount Merapi Yogyakarta

Metamorphic Rocks

Metamorphic rocks are one of the main groups of rock that are the result of transformation or alteration of a rock type that has been there before, protolith, by a process called metamorfisme, which means "changing forms". Protolith subjected to heat (greater than 150 ° Celsius) and extreme pressure will experience physical changes and / or chemistry major. Protolith can form sedimentary rocks, igneous, or metamorphic rocks, others are older. Some examples are gneis metamorphic rock, slate, marble, and skist.
Metamorphic rocks make most of Earth's crust and are classified on the basis of texture and chemical composition and mineral (metamorphic facies) They formed far below the surface of the earth by the great stress from the rocks above and high pressures and temperatures. They are also formed by the intrusion of molten rock, called magma, into solid rock and is formed mainly at the contact between magma and high-temperature rocks.
Research metamorphic rocks (now exposed at the earth's surface caused by erosion and uplift) provides us valuable information about temperatures and pressures that occur deep within the earth's surface.