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