1989 West Papua earthquake

1989 West Papua earthquake

Date	August 1, 1989 (1989-08-01)
Origin time	23:17 UTC 9:17 AEST
Magnitude	6.0 Mw
Epicenter
Type	Dip-slip
Areas affected	Indonesia
Max. intensity	VIII (Severe)
Casualties	120 dead 120 injured

The 1989 West Papua earthquake struck West Papua, Indonesia – then Irian Jaya province – on August 1 with a moment magnitude of 6.0 and a maximum Mercalli intensity of VIII (Severe). Around 120 people were killed, mainly due to landslides and mudslides.

Details and relief

The West Papua earthquake struck at 9:17 local time and measured M_s 5.7 and 6.0 on the moment magnitude scale. Its epicenter was located 299 km (186 mi) south of Jayapura; the earthquake reached as far as Wamena. There were multiple aftershocks.

The earthquake killed 120 people and left 120 injured; all of the dead were recovered from the villages of Holuon, Pasema, and Soba. Many of these deaths and injuries derived from landslides that covered two villages and disrupted sections of the Baliem River, practically flooding three villages and depositing tons of mud. One of these landslides was 200 m (660 ft) tall; there were eleven in total. A large portion of the dead consisted of Dhani tribesmen.

Local authorities distributed food, blankets, clothing, and money to survivors. Helicopters supplied food and other relief supplies, but they were slowed by cracks in the local airstrips. More than 25 survivors were treated for severe injuries and another 100 for less grave maladies. Between two hundred and three-hundred people were evacuated in the aftermath of the tremor, and 3,500 Hupla people were resettled at a lower altitude, thus moving them from their traditional settlements.

Geology

The focal mechanism for the earthquake demonstrated reverse faulting. The region around the epicenter has a history of powerful earthquakes. Between two earthquakes in 1976 and 1981, 1000 people died. There have been large earthquakes in the region as recently as 2009 and 2010.