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Earthquake in Indonesia |
The Indonesian region is one of the most seismically active zones on earth. It is surrounded by at last four different plates that collide with deep ocean trenches and is dotted with many active volcanoes that lie on the Sunda arc. Experts say this makes the region especially Java, highly unstable tectonically.
Indonesia has 76 volcanoes that have erupted to date - the largest number for any volcanic region - placing Indonesia second after Japan as the region with the most volcanic eruptions.
An earthquake results when faults within the earth's crust slip out of alignment when plates, which are constantly moving underground as heat inside the earth is released, undergo severe friction. The epicenter of an earthquake is the location on the surface of the earth directly above the spot where the earthquake starts. The spot within the earth where the earthquake starts is known as the hypocenter.
There is no science in predicting an earthquake. A major earthquake can be preceded by a number of small earthquakes known as foreshocks. These are similar to the aftershock quakes that come after an earthquake. But it is only after the 'big one' that the foreshock and aftershock can be differentiated.
Fast Facts:
Most earthquakes occur along plate boundaries and one of the most active plate boundaries is around the Pacific Plate commonly referred to as the Pacific Ring of Fire which Indonesia lies in.
It is estimated that there are 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt, and 100 of them cause damage.
Most earthquakes occur at depths of less than 80 km from the Earth's surface.
Although massive friction within the earth results in an earthquake, there is in fact little noise caused by an earthquake. The rumblings that are heard are produced by buildings and other structures being rocked.
Most deaths and injuries that occur during earthquakes are often not due to quakes but result from fires and collaping structures set off the earthquake.
A tsunami and a tidal wave are two different unrelated phenomenona. A tidal wave is a shallow water wave caused by the gravity pull between the Sun, Moon, and Earth. A tsunami is a sea wave caused by an underwater earthquake or landslide which pushes the ocean water in a certain direction. - CNA/sf
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