An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.
In its most generic sense, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus or hypocenter. The term epicenter refers to the point at ground level directly above the hypocenter.
Oceanic plate is a larger mass meeting when collide with continental crust in collision zones (subduction) will infiltrate downwards. Plate movement would experience deceleration due to friction of the sheath of the earth. Slowing motion that causes the accumulation of energy in the subduction zone and fault zones.
Result in zones that happens the pressure, tension, and shear. At the plate elasticity limit is exceeded, then there was a rock fracture that was followed by energy loss of a sudden. This process menimbukan vibration of particles in all directions, called the earthquake waves.
The Indonesian archipelago lies in meeting the world's three major plates of the Australian Plate, Eurasian, and Pacific. Eurasian Plate and Australia collided off the west coast of Sumatra Island, off the south coast of Java, Nusa Tenggara archipelago off the southern coast, and turned to the north to the waters south Maluku. Between Australia and the Pacific plate collision occurred around the island of Papua. While the meeting between the three plates were happening around Sulawesi.
The intensity of earthquakes is the level of damage that was felt at the location of occurrence. The score is determined by assessing the damage it produces, its effect on objects, buildings, and land, and consequently on the people. This scale is called the MMI (Modified Mercalli Intensity) was introduced by Giuseppe Mercalli in 1902.
Earthquake magnitude is a parameter that is measured on the basis that occurs in certain areas, due to earthquake shocks at the source. The unit used is the Richter Scale. This scale was introduced by Charles F. Richter in 1934. For example, earthquakes with a force 8 on the Richter Scale equivalent explosive power of TNT weighing 1 gigatons or 1 billion tons.
Hopefully we can take the wisdom and lessons from beberaap case of the earthquake in Indonesia, then and in the future. Because, based on the explanation above, earthquakes including the only kind of natural disaster potential and intensity of occurrence is very high and very common. Here are 54 earthquakes that have occurred with or Magnitude Richter scale of magnitude greater than 5
