Two very strong earthquakes – M6.8 and M6.9 – hit off the coast of southern Sumatra, Indonesia

Two very strong earthquakes registered by the USGS as M6.8 and M6.9 hit off the coast of southern Sumatra, Indonesia on August 18, 2020, at 22:23 and 22:29 UTC, respectively. The quakes hit at depths of 22 and 26 km (13.6 and 16.1 miles), according to the USGS. EMSC is reporting M6.8 at 10 km (6.2 miles) and M6.9 at 39 km (24.2 miles); BMKG registered them as M6.9 and M6.8 at 10 and 11 km.

The epicenters of both quakes were located about 140 km (87 miles) WSW of Bengkulu (population 309 712), Indonesia.

There are no people living within 100 km (62 miles).

No tsunami warning was issued and there were no immediate reports of casualties or major damage.

1 753 000 people are estimated to have felt light shaking.

The USGS issued a green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.

Overall, the population in this region resides in structures that are vulnerable to earthquake shaking, though resistant structures exist. The predominant vulnerable building types are unreinforced brick with concrete floor and precast concrete frame with wall construction.

Recent earthquakes in this area have caused secondary hazards such as landslides that might have contributed to losses.

"The first earthquake was quick…but another one hit shortly after and it was just as strong," one resident of Bengkulu told AFP.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google