M 6.7 BANDA SEA EARTHQUAKE ON WEDNESDAY, DECEMBER 21ST, 2016
RELATIVE PLATE MOTIONS
Indonesian archipelago is located in the convergence zone of four major tectonic plates:
Eurasian plate, Indian-Australian plate, Pacific plate and Philippine plate. Interaction of these plates affected the seismo-tectonic of the Indonesian region.
The Indian-Australian plate moving northwards relative to Eurasian plate and the Pacific plate moving westward relative to both Indian-Australian and Eurasian plate.
Moreover, as a result of the India and Australia plates converging with and subducting beneath the Sunda plate at a rate of approximately 50 to 70 mm/yr.
An earthquake with a magnitude of 6.7 Mw (USGS) occurred at Banda Sea Region on Desember 21, 2016. The epicenter was on deep offshore with a depth of 151.1 km, but there were no tsunami warning was issued because the hypocenter of earthquake is too deep so the energy released is not strong enough to trigger a tsunamis.
Geologically, the Tectonics of Banda Arc is complex convergence zone between three major tectonic plates, Eurasian plate, Indo-Australian plate, and Pacific plate. The focal mechanism solution indicates Transpression (compression+shear) due to collision of Banda Arc with the Indo-Australian passive continental margin.
Based on the shake map of Maipark Cat Model, the intensity of the quake was felt in Kab. Maluku Barat Daya IV MMI; Kab. Belu and Kab. Malaka III MMI. The intensity was very low and indicate light shaking.
EXPOSURE AND LOSS
Preliminary result from Maipark Cat-model has estimated economic (number of houses) no losses from this event. No casualties or damaged were reported from media and local disaster management agency (BPBD). We expect no or minor under deductible insurance losses.