EARTH DAY for GLOBALWARMING

Large-scale earthquake will knock down anything on earth that unsound and fragile. This phenomenon is not just demolish the building, but also makes landslides, broke, and ambles. Beyond that, an earthquake of the coast is also a potential cause tsunamis. That is a series of threats to the population in the earthquake-prone areas.

As long as the earth rotates, the movement of plates covering the earth and float on the magma will never stop. Antarlempeng collision or the crust is what causes earthquakes continue to occur after another all over the world.

When one location in the boundary layer of rocks collapsed due to the earth's crust holding the pressure plate merapuh, rocks that would seek a new stable position. During this process will be a series of aftershocks, the main pascagempa. This can result in cracked buildings and fragile finally collapsed.

For earthquakes in Padang, 30 September, hack earthquake even hundreds of times before the incident. Since the earthquake in Aceh, December 26, 2004, Padang and surrounding areas are often hit by earthquakes scale 4 to 6 on the Richter scale. "The numbers in the hundreds," said Sujabar, officials at the National Earthquake Center Meteorology, Climatology, and Geophysics.

Shocks in a long time has weakened gradually building structures that are not designed to withstand earthquakes, among others, indicated by the wall fractures. Appeal to the public to do to strengthen buildings vulnerable to earthquakes has been done. "But, unfortunately this is ignored because they are considered a big earthquake would not come," said Febrin A Ismail, Coordinator of the Expert Group of the Tsunami Alert (Kogami) West Sumatra.

Avalanche and ambles

Other threats lurk after the earthquake is a landslide and ambles. This happened in the hills because the reduction in forest cover.

The decline of forest areas in the region will open up the potential slope and landslide eroded as rain. This condition starts during the dry season. As a result of exposure to intense sunlight, land surface bond "naked" would be weakened and stretched.

Avalanches generally occur in the transition from dry to rainy season, especially in the area of land type easy go. As the rain washed constantly, a weakened bond would be broken because the burden of water in the pores. Bond rupture is characterized by avalanches of land. The threat of landslides to be greater when the slope of the fragile perch building, especially when rocked by an earthquake.

Longsornya slopes in some areas in West Sumatra pascagempa, September 30, among others, triggered by these conditions. It is also common in Cianjur, West Java, September 2, 2009.

Seeing the trend merambahnya residential area to the hills caused by rising populations in earthquake-prone areas, in future events such as landslides during the earthquake in Cianjur, Solok and Padang will happen also in other areas prone slopes and densely populated quake.

In addition to landslides, amblesnya surface can also occur in areas hit by the earthquake. As a result of the earthquake, the source of underground water mixed to happen likuifaksi or pelembekan land. Land that had high loading and hollow will ambles.

Domino effect

Domino effect could occur in kegempaan and fault segments adjacent to the collapsed rocks are the source of the earthquake. Conditions that, among other things pascagempa Padang earthquake followed the next day of Jambi, which is sourced from Semangko fault.

"We kegempaan Mentawai segment also require attention after the earthquake in Padang late last month," says Danny Hilman, geologists from the Central Research Geoteknologi Indonesian Institute of Sciences.

Because the earthquake source is located on the west bank, the Mentawai segment called megathrust, which stretched from the island of Siberut island until Pagai. LIPI research shows the Mentawai Islands, the year 1650 an earthquake had occurred on SR 8 in Siberut Island. Years 1797 and 1883 as re-scale earthquake in the area appeared.

Second quake-based research and sedimentary coral-caused tsunami in Padang as high as 10 meters. The propagation modeling 8,7-8,9 tsunamis by earthquakes in 1797 and SR 1833, which created a tsunami expert ITB, Hamzah Latief, the wave will reach the coast of Padang in 30 minutes with a height of nearly 5 meters.

Mentawai segment is part of the system in western Sumatra kegempaan which is divided into four main segments (Simelue, Nias, Mentawai, Enggano). 10 years since the last earthquake in this segment "pounding".

"The emergence of the earthquake last September that the Mentawai segment may disturb the sleep, to cause a tsunami," says Danny.

Earthquakes in the western islands of Sumatra that repetition period of about 200-300 years. This penunjaman effects of the pressing plate edge Indoaustralia Eurasian plate beneath the western part of fault Semangko up to the islands off the coast of Sumatra. The speed of the pressure plate 6 to 7 centimeters per year.

Rocks at the end plate at a time will be bounced for not being able longer stand the pressure. This is marked by a large earthquake, a shift position in the segment's mainland and the island from the mainland menjauhnya a few meters from its original position. Pascagempa year 2004, the islands off the coast of Banda Aceh 1-3 meters away.

In addition to natural phenomena that accompany large earthquakes, the impact is the threat of disease, food shortages, as well as psychological trauma victims who lost property and family.

Because of that, Danny reminds all parties in the Valley must be vigilant and to anticipate potentially facing a tsunami earthquake recurrence.