"It is strongly believed the quake was caused by the Mamuju thrust. This is apparent from the result of the source mechanism analysis, which shows that the quake has a thrust fault," coordinator of the earthquake and tsunami mitigation section at the Meteorology, Climatology, and Geophysics Agency (BMKG), Daryono, said on Thursday.
The result of the BMKG’s analysis shows the epicenter of the quake was located on land, four kilometers northwest of Majene, West Sulawesi, at a depth of 10 kilometers, he informed.
Judging by its epicenter and hypocenter depth, the quake, which struck at 1:35 p.m. WIB (West Indonesia Standard Time), was a shallow quake caused by an active fault, he said.
The tremor was felt in Polewali at V-VI MMI, Mamuju and Majene at IV MMI, North Mamuju and Central Mamuju at III-IV MMI, Toraja and Mamasa at III MMI, and Pinrang, Poso, Pare-pare, and Wajo at II-III MMI.
According to field reports, Daryono said, the sudden and strong tremor prompted local residents to stay outdoors.
"Looking at the shake-map based on the BMKG's analysis, the quake appeared to potentially cause damage," he noted.
As of 2 p.m. WIB, the quake had been followed by two aftershocks of magnitude 4.9 on the Richter scale. (INE)
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EDITED BY INE