AIR Worldwide Analyzes Recent Earthquakes in Indonesia

January 7, 2009

According to catastrophe risk modeling firm AIR Worldwide, a series of strong earthquakes shook the West Papua province of Indonesia this past weekend. The U.S. Geological Survey reported that the initial quake measured M7.6 and struck on Saturday, January 3 at 19:43 UTC (Sunday, January 4, at 4:43 A.M. local time) 95 miles (152 kms) north of the city of Manokwari at a depth of 22 miles.

Dozens of aftershocks followed, the strongest of which measured M7.4 and was felt as far as Australia, some 1,300 miles (2080 kms) away. A tsunami alert was issued by the Indonesian Meteorology and Seismology Agency, but was withdrawn within an hour after it was determined that the quake epicenter was on land. More than 800 houses have been damaged and two three-story hotels, the Kali Dingin Hotel and Hotel Mutiara, have collapsed.

“The earthquakes occurred as a result of thrust faulting on a plate boundary along the northwest coast of the island of New Guinea in the New Guinea trench subduction zone,” explained Dr. Bingming Shen-Tu, Project Manager at AIR Worldwide.

“The initial quake and the magnitude 7.4 aftershock that occurred three hours later both ruptured the plate boundary subduction zone fault. Eastern Indonesia is located in the Pacific ‘Ring of Fire,’ an area of high volcanic and earthquake activity encircling the Pacific Basin. The region is characterized by complex tectonic activity involving numerous small plates whose movements accommodate the large-scale convergence between the Australia, Pacific, and Eurasia plates.”

“Although the plate convergence rate across the New Guinea subduction zone is very high, few very large magnitude earthquakes have been recorded here in the last century,” added Dr. Shen-Tu. “The only similar historic event recorded in the last 100 years is the 1994 M7.4 earthquake that occurred in the same area as the M7.4 aftershock. This subduction zone has not been well defined by modern seismicity, but these two events suggest that it can generate large earthquakes.”

West Papua is located about 1,800 miles (2880 kms) east of Indonesia’s capital, Jakarta, and occupies the western tip of the island of New Guinea. It is one of the nation’s most sparsely populated and least developed regions. The coastal city of Manokwari is the capital of West Papua and is home to an estimated 167,000 residents, most of whom live in low-lying brick and cement unreinforced masonry structures.

Source: AIR Worldwide –

Was this article valuable?

Here are more articles you may enjoy.