Alaska Hit by 7.3-Magnitude Earthquake: A Look at the Region’s Most Powerful Quakes

A 7.3-magnitude earthquake struck the U.S. state of Alaska at 12:37 p.m. local time, prompting a tsunami warning for parts of the region. The quake’s epicentre was located approximately 54 miles (87 km) south of Sand Point, near Popof Island in the central Alaska Peninsula. With a depth of 20.1 km, the earthquake is categorized as shallow, increasing the risk of surface-level impact.

The National Oceanic and Atmospheric Administration (NOAA) issued a tsunami warning for much of the Alaska Peninsula, extending into the southernmost portion of mainland Alaska and approaching the Anchorage region.

Authorities ordered the immediate evacuation of low-lying coastal areas as a precaution.

Why Alaska Is Prone to Earthquakes

Alaska lies along the boundary between the Pacific and North American tectonic plates, where intense seismic activity is generated by subduction zones. As a result, Alaska experiences some of the strongest earthquakes in the world. Below are a few major events:

1. 1964 Great Alaska Earthquake (Prince William Sound)

Date: March 27, 1964 Magnitude: 9.2 (second strongest globally) Depth: ~25 km

Impact:

Devastated Anchorage and several coastal towns Triggered massive tsunamis reaching as far as California and Hawaii 131 fatalities (mostly tsunami-related) Caused widespread uplift and subsidence Estimated damage: $300+ million (1964 USD)

2. 1957 Andreanof Islands Earthquake

Date: March 9, 1957 Magnitude: 8.6 Location: Aleutian Islands

Impact:

Generated a Pacific-wide tsunami Reached Hawaii, causing coastal flooding Damage was limited due to the remote location

3. 1965 Rat Islands Earthquake

Date: February 4, 1965 Magnitude: 8.7 Location: Western Aleutian Islands

Impact:

Triggered a tsunami with waves over 10 meters Few casualties due to the isolation of the region

4. 2018 Anchorage Earthquake

Date: November 30, 2018 Magnitude: 7.1 Depth: ~46 km Location: Just north of Anchorage

Impact:

Major infrastructure damage (roads, airport, buildings) No fatalities, thanks to updated building codes Followed by thousands of aftershocks

5. 2021 Chignik Earthquake

Date: July 28, 2021 Magnitude: 8.2 Depth: ~32 km Location: Near Chignik, South Alaska Peninsula

Impact:

Strong shaking felt across the region Tsunami warnings issued, but no major damage No injuries reported due to remote location and timely alerts