Diposkan : February 18, 2016
Relative Plate Motions
The subductions of Eurasia and indo-australia plate are the main source of the seismic activities in this area. Subduction angle in this area is smaller than subduction angle in West of Sumatera. Subduction angle is not too steep at the boundary, but becomes steeper beneath the Sumba Island.
Discussion
6.3 Mw earthquake occurred in February 12th, 2016 at 10:02:23 UTC. BMKG reported depth of the earthquake is 10 km. USGS reported deeper hypocenter location that resulted more reliable loss estimation compared with reported damage we received. According to USGS, the earthquake focus was 9.744S and 119.451E at the 28 km distance from the surface. Epicenter was located in the South beach of Sumba Island.
Due to small degree of the subduction angle, it is doesn?t need much energy to generate tsunami in this area, not as much as in Sumatera that has steeper subduction angle in the plate boundary. M 7.8 Flores earthquake was able to generate devastating tsunami wave in the beach. It is much smaller energy compare to M9+ Sumatera tsunamigenic earthquake in 2004.
Exposure and loss
The most affected area are Sumba Barat, Sumba Barat Daya and Sumba Tengah. Based on GMPE, these areas felt around V-VII MMI. On risk of sum insured on these areas is IDR 230 billion.
Our loss estimation modeling resulted IDR 1-5 billion losses of economic losses due to ground shaking and we expect very small or no insurance losses.
For full report detail, click here.