Very strong M7.1 earthquake hits near the coast of Southern Sumatra, Indonesia

A very strong and shallow earthquake registered by the USGS as M7.1 hit near the coast of Southern Sumatra, Indonesia at 20:00 UTC on April 24, 2023 (03:00 LT, April 25). The agency is reporting a depth of 15.5 km (9.63 miles). BMKG is reporting M6.9 (down from M7.3) at a depth of 84 km (52.1 miles). EMSC is reporting M6.8 at a depth of 16 km (9.9 miles).

The epicenter was located 171.2 km (106.4 miles) SSE of Teluk Dalam, North Sumatra, and 177.5 km (110.3 miles) W of Pariaman, West Sumatra, Indonesia.

Based on pre-run model scenarios, there is no tsunami threat to countries in the Indian Ocean, InaTEWS-BMKG said in their PUBLIC TSUNAMI BULLETIN NUMBER 2 (THREAT ASSESSMENT BULLETIN). No further bulletins will be issued unless the situation changes.

9 000 people are estimated to have felt very strong shaking, 21 000 strong, 37 000 moderate and 2 357 000 light.

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 tsunamis and landslides that might have contributed to losses.

Liquefaction triggered by this earthquake is estimated to be significant in severity and (or) spatial extent, according to the USGS. However, the number of people living near areas that could have produced liquefaction in this earthquake is limited.

Estimated population exposure to earthquake shaking

Selected cities exposed

Featured image credit: TW/SAM, Google