Topline
A tsunami advisory was lifted Wednesday afternoon for a portion of the Alaskan Peninsula coastline following a 7.3 magnitude earthquake that shook 50 miles off its coast, after the National Weather Service initially issued a tsunami warning, saying there was an “imminent” threat.
Key Facts
The tsunami alerts applied to the Alaska Peninsula areas from the Kennedy Entrance to Unimak Pass and included the cities of Cold Bay, Sand Point and Kodiak, though most of the region is remote with an extremely small population.
The NWS noted “with reasonable confidence” the Kenai Peninsula Borough locations will not see tsunami impacts.
It appeared residents in Anchorage, Alaska, the most populated city in the state, were given mobile phone warnings about the tsunami warning, though the NWS and the Anchorage Office of Emergency Management said the tsunami warning did not apply to the Anchorage area.
The 7.3 magnitude earthquake struck at a depth of 12.4 miles, with reports of shaking being made as far as Anchorage, which is some 800 miles away from Sand Point.
Get Forbes Breaking News Text Alerts: We’re launching text message alerts so you’ll always know the biggest stories shaping the day’s headlines. Text “Alerts” to (201) 335-0739 or sign up here.
Surprising Fact
Wednesday’s quake is one of the largest Alaska has seen in recent years, according to Earthquake Track, which uses data from the United States Geological Survey. The most recent major quakes in Alaska occurred in 2023 and 2021, with 7.2 magnitude and 7.6 magnitude tremors, respectively. Both of those quakes also occurred off the coast of Sand Point, a scarcely populated commercial fishing hub.
Key Background
Alaska is home to multiple active fault lines and the Alaska-Aleutian Megathrust, a major subduction zone, which all contribute to high quake activity in the region. The subduction zone has produced some of the largest earthquakes ever recorded, such as the 1964 Alaska earthquake that measured as a 9.2 magnitude, according to the Alaska Earthquake Center. Local tsunamis triggered by the quake resulted in 122 fatalities. The state’s geography and subduction zone makes it particularly susceptible to tsunamis that can strike within minutes as opposed to hours.
Further Reading
Maps: Tracking a Tsunami Alert on the Alaska Coast After a 7.3-Magnitude Earthquake (The New York Times)
