The epicenter of the earthquake — which broke out at 4.38 p.m. local time — was located in the sea, 49 kilometers north of the Simeulue district capital of Sinabang and at a depth of 10 km, chief of the Aceh Besar Geophysics Station, Djati Cipto Kuncoro, informed.
Kuncoro said he was awaiting the report on the damage caused by the earthquake.
Based on its epicenter and hypocenter depth, the earthquake was a shallow earthquake caused by subduction beneath Sumatra Island, according to the Meteorology, Climatology, and Geophysics Agency (BMKG).
"The result of source mechanism analysis shows the earthquake had flat movement mechanism. By 5.30 p.m. on Monday (October 19, 2020), there has been an aftershock of magnitude 3.2," Kuncoro said.
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Earlier on October 15, 2020, an earthquake of magnitude 5.2 had hit Meulaboh district in Aceh.
A quake of magnitude 5.4 can cause substantial damage to land.
Aceh had borne the brunt of a 9.1-magnitude quake and subsequent tsunami on December 26, 2004, which had led to hundreds of thousands of people losing their lives or going missing.
Indonesia is located on the geographically active Pacific Ring of Fire and holds some 40 percent of the world's geothermal reserves.
According to Live Science, the Ring of Fire, or the Circum-Pacific belt, is the world's greatest earthquake belt owing to the presence of fault lines running from Chile to Japan and Southeast Asia
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