7.8 earthquake strikes Indonesia hours after 8.4 quake
7.8 earthquake strikes Indonesia hours after 8.4 quake
mongabay.com
September 13, 2007
A second powerful earthquake struck Indonesia, just 12 hours after it was rocked by the strongest earthquake of 2007.
Both earthquakes were centered off the coast of Bengkulu on the island of Sumatra. The first quake — magnitude 8.4 — occurred at a depth of 18.6 miles, the second — magnitude 7.8 — at a depth of 6.2 miles.
Both quakes caused widespread panic and triggered tsunami warnings for Indonesian and other Indian Ocean nations devastated by the December 26, 2004 tsunami that killed 230,000 people. That wave was caused by a magnitude-9 earthquake off Sumatra.
 Image modified from USGS |
The 8.4 quake caused a 3-feet tsunami in Padang about 20 minutes after the shaking. The tsunami caused minimal damage but at least three people were killed by collapsed buildings and fires from the earthquake. A further seven people were killed in Bengkulu according to the Social Affairs Department.
The earthquake was felt widely in the region, causing skyscrapers to sway in Jakarta, Singapore, and Malaysia.
Last December scientists from the University of Southern California (USC) and California Institute of Technology (Caltech) warned that Indonesia could be due for another large tsunami like the one that devastated the island on December 26, 2004.
The U.S. Geological Survey (USGS) said that the magnitude-8.4 earthquake that struck Sumatra, Indonesia, on Sept. 12, 2007, was the largest of four magnitude 8 or greater earthquakes that have occurred worldwide since January and the largest earthquake in Indonesia since the magnitude-8.6 “Nias” earthquake of March 2005. USGS added that the Earth produces an average of one magnitude-8 or larger earthquake and about 15 to 20 magnitude-7 earthquakes per year.
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Image modified from USGS |
Another large tsunami could hit Indonesia soon (December 4, 2006).
Researchers at the University of Southern California (USC) and California Institute of Technology (Caltech) say that the Indonesian island of Sumatra could be due for another large tsunami like the one that devastated the island on December 26, 2004. Their research is published in the December 4 Proceedings of the National Academy of Sciences. Based on analysis of historical earthquakes, the researchers say that another tsunami produced from another giant earthquake is “likely to flood densely populated sections of western coastal Sumatra,” south of areas affected by the 2004 tsunami. The researchers note that the southeastern section of the same fault that caused the 2004 tsunami triggered giant quakes in the two great quakes and tsunamis in 1797 and 1833, and that “such events appear to recur on average every 230 years.”