Deep M7.1 earthquake hits Bali Sea, Indonesia

A very strong earthquake registered by the USGS as M7.1 hit the Bali Sea, Indonesia at 19:55 UTC on August 28, 2023. The agency is reporting a depth of 516 km (320 miles). EMSC is reporting the same magnitude and depth.

The epicenter was located 184 km (114 miles) NNE of Gili Air (population 1 800) and 207 km (129 miles) NNE of Mataram (population 429 651), West Nusa Tenggara, Indonesia.

3 750 000 people are estimated to have felt weak shaking.

There is no tsunami threat from this earthquake.

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 that might have contributed to losses.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google