US: A magnitude-5.4 offshore earthquake occurs near the Andreanof Islands, Alaska, at around 07:21 Sept. 21

A magnitude-5.4 earthquake occurred near Andreanof Islands, Alaska, at around 07:21 Sept. 21 The epicenter was about 150 km (92 miles) west-southwest of Adak. The tremor occurred at a depth of about 43 km (26 miles), and light shaking was probably felt throughout the Andreanof Islands. There have been no initial reports of damage or casualties as a result of the earthquake; however, significant damage is unlikely. It could take several hours until authorities can conduct comprehensive damage assessments, especially in remote areas. Light-to-moderate aftershocks are likely over the coming days. The event has not prompted any tsunami advisories.

Officials may temporarily shut down transportation infrastructure in the tremor zone to check for damage. Minor disruptions could occur during shutdowns, but service will likely resume quickly if no damage is found. Utility outages are possible, particularly near the earthquake's epicenter.