Second Major Earthquake Rocks Island of Sumatra

Two powerful earthquakes struck Indonesia's Sumatra island Monday, according to the U.S. Geological Survey.

The most recent quake had a preliminary magnitude of about 6.7. Another, which occured early Monday morning, had a magnitude of 7.3, according to the U.S. Geological Survey.

_©FOXnews



Magnitude 6.7
Date-Time
*Monday, February 25, 2008 at 18:06:05 UTC
*Tuesday, February 26, 2008 at 01:06:05 AM at epicenter
Location 2.361°S, 99.920°E
Depth 35 km (21.7 miles) set by location program
Region KEPULAUAN MENTAWAI REGION, INDONESIA
Distances
*164 km (102 miles) SSW (197°) from Padang, Sumatra, Indonesia
*304 km (189 miles) WNW (301°) from Bengkulu, Sumatra, Indonesia
*364 km (226 miles) SSW (208°) from Pekanbaru, Sumatra, Indonesia
*596 km (370 miles) SW (227°) from SINGAPORE

Third Major Earthquake Rocks Island of Sumatra

AKARTA, Indonesia — Another powerful earthquake struck Indonesia's Sumatra island Monday, according to the U.S. Geological Survey. The latest on Monday evening was at least the third: a 6.9-magnitude aftershock strike off the coast of Sumatra, according to UGS. No tsunami warning was immediately issued. It appeared to be at least the third in a series of quakes, with two or more strong ones reportedly hitting the same region earlier on Monday. There was a brief tsunami warning after the first quakes, but no reports of damage, injuries or deaths.

The second quake had a preliminary magnitude of about 6.7. Another, which occurred early Monday morning, had a magnitude of 7.3, according to the U.S. Geological Survey. The geophysics agency issued a tsunami bulletin following the quake first quake, but canceled it an hour later after determining no waves were generated.



_{Bron: FoxNews}


| Gewijzigd: 26 februari 2008, 00:23 uur, door Marga

Indonesia Fault Line Quakes Nearly 20 Times This Month

The fault line that spawned the 2004 Indian Ocean tsunami has ruptured nearly 20 times this month, causing three strong earthquakes. The activity shows the stress the seam is under and could be a harbinger of worse to come, scientists warn. Kerry Sieh, from the California Institute of Technology, has studied the fault for more than ten years. He likened it to a length of rope in an imaginary tug of war between a group of men and an elephant. "One by one, two by two, the men are getting worn out and are letting go of the rope. That puts more stress on each of the remaining men," he wrote in an e-mail Tuesday. "Who knows which one will let go next, or whether they will let go all at once?" Sieh and other scientists using Global Positioning System transmitters to measure the uplift of the quakes say another massive temblor sometime in the next hundred years or so is likely, but they cannot predict exactly when that will occur.

Klik hier voor het artikel:"The Next Big One—Earthquake Technology"

"Nothing New"
The fault line is the boundary between the Eurasian and Pacific tectonic plates that have been pushing against each other for millions of years, causing huge pressure to build up. It runs the length of the west coast of Sumatra, Indonesia, about 125 miles (200 kilometers) offshore. The steady stream of earthquakes it has produced this month do not seem to be alarming residents much. Witnesses say some have prompted people to flee swaying homes, but few are heeding or are aware of the tsunami warnings that routinely accompany the big jolts. "People did not really care because such a tremor is nothing new," Erwin, a resident in the coastal town of Padang, said minutes after a powerful quake early Tuesday. "It was just like the one in the afternoon," said Erwin, who, like many Indonesians, goes by a single name.



"Part of a Chain"
The 2004 earthquake off Aceh province in northwest Sumatra (see map of Indonesia) had a magnitude of 9.2, making it the most powerful temblor in four decades. It triggered a tsunami that killed 230,000 people in 12 Indian Ocean countries, with more than half the victims in Indonesia.

Three months after the tsunami, a magnitude 8.6 quake farther down the fault line killed a thousand people. Then in September last year, an 8.7 quake opposite Bengkulu province damaged thousands of homes, killed about 25 people, and sent a ten-foot (three-meter) tsunami crashing into nearby coastlines.

Last Wednesday a magnitude 7.4 quake killed three people and damaged scores of houses. (See story.) Since Sunday, four other events strong enough to prompt tsunami warnings by international agencies have jolted the region. "They are best seen as part of a chain that began in 2004," said Dr. Fauzi, a top scientist at Indonesia's National Earthquake Center. "The stability of the fault has been disturbed," said Fauzi, who goes by a single name. Since the Indian Ocean tsunami, Indonesia has spent millions of dollars to establish a nationwide tsunami warning system, but there are still only a few warning sirens in Sumatra's threatened western coast and other beach areas. Officials and residents of the two populous cities of Padang and Bengkulu said no sirens sounded following the recent earthquakes despite warnings issued by the country's Meteorology and Geophysics Agency. "We don't have such equipment," said Suyud, an official at Bengkulu's Meteorology and Geophysics Agency. "If there were tsunami warnings issued it was only government officials who knew that from text messages on their cell phones."

_{Copyright 2008 Associated Press. / National Geographic News} | Gewijzigd: 27 februari 2008, 08:56 uur, door Marga