Shallow M6.0 earthquake hits North Sumatra, Indonesia

A strong and shallow earthquake, registered by the BMKG as M6.0, hit northern Sumatra at 19:28 UTC on September 30, 2022. The agency is reporting a depth of 10 km (6.2 miles). USGS is reporting M5.9 at a depth of 13.2 km (8.2 miles); EMSC M5.8 at a depth of 40 km (25 miles).

The epicenter was located 41 km (25 miles) NNE of Sibolga (population 79 714), 63 km (39 miles) S of Tomok Bolon (population 10 000), 64 km (40 miles) S of Parapat (population 10 000) and 168 km (105 miles) S of Medan, North Sumatra, Indonesia.

According to the USGS PAGER, 11 000 people are estimated to have felt very strong shaking, 127 000 strong, and 1 023 000 moderate.

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 informal (metal, timber, GI etc.) and heavy wood frame construction.

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

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google