Alaska Earthquake: 6.2 magnitude tremor strikes days after major quake, no damage reported

Alaska’s seismically active coast has seen two major earthquakes in less than a week, both confirmed by the National Center for Seismology (NCS).

On 21 July, an earthquake measuring 6.2 on the Richter scale struck the Alaska Peninsula. The tremor occurred at 03:58 IST at a depth of 48 kilometres. The NCS shared the update on X, stating, "EQ of M: 6.2, On: 21/07/2025 03:58:02 IST, Lat: 54.99 N, Long: 159.98 W, Depth: 48 Km, Location: Alaska Peninsula."

No injuries or damage have been reported so far.

Earlier earthquake of 7.3 magnitude triggers tsunami warning

Just four days earlier, on 17 July, a stronger quake of magnitude 7.3 had hit the same region. The NCS recorded that earthquake at a depth of 36 kilometres, again shallow enough to be considered dangerous.

The NCS posted the following details on X, "EQ of M: 7.3, On: 17/07/2025 02:07:42 IST, Lat: 54.91 N, Long: 160.56 W, Depth: 36 Km, Location: Alaska Peninsula."


This quake triggered a tsunami warning along parts of coastal Alaska. According to The New York Times, the US Tsunami Warning System issued the alert soon after the tremor in the Gulf of Alaska.

In the United States, a tsunami warning signals an immediate need to move to higher ground or inland. A tsunami advisory urges people to stay away from coastal waters. A tsunami watch, on the other hand, means experts are still assessing whether there’s a threat.

Shallow earthquakes pose a greater risk

Both of these earthquakes were shallow. That matters because when seismic activity starts close to the surface, the waves don’t have far to travel. This results in stronger ground shaking.

The impact can be more severe. Buildings, roads, and other infrastructure face greater stress. Casualties are also more likely in heavily affected zones, especially if aftershocks continue.

The recent quakes highlight this vulnerability. Though no damage has yet been reported, the shallow depths of both tremors point to a continued risk of aftershocks.

Alaska’s volatile geology

These events are not isolated. The Alaska Peninsula sits on the Alaska-Aleutian subduction system, one of the most seismically active zones on the planet.

Over the last hundred years, this region has produced more earthquakes above magnitude 8 than anywhere else in the world. The area is also prone to coastal and underwater landslides, which can trigger tsunamis.

There are more than 130 volcanoes and volcanic fields in the area. In fact, over 75 percent of all US volcanic eruptions in the last 200 years have taken place here.

With tectonic plates grinding under the surface and the ocean close by, the region remains under constant geological pressure. Scientists continue to monitor the situation closely.