Shallow M5.8 and M5.9 earthquakes hit southern Iran

Shallow earthquakes registered by GSRAS as M5.8 and M5.9 hit southern Iran at 04:59 UTC (08:29 LT) and 05:10 UTC (08:40 LT) on October 17, 2023. The agency is reporting a depth of 10 km (6.2 miles). USGS registered them as M5.1 and M5.5.

The epicenters were located 62.8 km (39 miles) NNW of Bandar Abbas (population 352 173) and 67.8 km (42.1 miles) SSE of Ḩājjīābād (population 23 309), Hormozgan Province, Iran.

According to the USGS PAGER, 1 000 people are estimated to have felt very strong shaking during the M5.5 (M5.9) earthquake, 4 000 strong, and 25 000 moderate.

The USGS issued a Yellow alert for shaking-related fatalities and a Green alert for economic losses. Some casualties are possible and the impact should be relatively localized. Past events with this alert level have required a local or regional level response.

Overall, the population in this region resides in structures that are vulnerable to earthquake shaking, though resistant structures exist. The predominant vulnerable building type is a low-rise nonductile concrete frame with infill 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