EARTHQUAKEM4.6

M4.6 earthquake near Adak, Alaska

Map: the earthquake near Adak, Alaska, with plate boundaries

A magnitude 4.6 earthquake struck 95 mi (153 km) west-northwest of Adak, Alaska on Sunday, October 25, 2026 at 17:49 UTC, at a depth of 95 mi (153 km), according to the U.S. Geological Survey. At this intermediate depth, shaking spreads out before it reaches the surface.

MagnitudeM4.6
Depth95 mi (153 km)
Time (UTC)Oct 25 17:49
Location52.19°N 178.81°W
Nearest townAdak · 153 km
Energy120 tons TNT
Aftershocks M2.5+0
Tsunami flagNo
See it on the live 3D globe →Watch live on YouTube🔔 Get alerts near you

Why here?

This earthquake struck about 126 mi (203 km) from the boundary between the North American and Pacific plates. Most earthquakes happen along plate boundaries like this one, where the pieces of Earth’s outer shell collide, pull apart or grind past each other. Stress builds up over years until the rock suddenly slips. At 153 km down, it most likely broke inside a plate that is sinking into the mantle beneath its neighbor, in what geologists call a subduction zone.

The red lines on the map are plate boundaries.

How strong was it?

Magnitude is logarithmic: each whole step releases about 32 times more energy. This magnitude 4.6 released roughly the energy of 120 tons of TNT. That is about 7.9 times the energy of a magnitude 4.0, a quake people nearby feel but that rarely causes damage. The strongest earthquake ever recorded, magnitude 9.5 in Chile in 1960, released about 22,000,000 times more than this one.

Aftershocks

In the first 11 hours after it, USGS recorded no smaller earthquakes of magnitude 2.5 or more within 62 mi (100 km).

Earthquake history here

Before this earthquake, USGS had recorded 242 earthquakes of magnitude 6 or larger within 300 km (186 mi) since 1900. The strongest:

Official details, updates and the shaking map: USGS event page.

See every earthquake on October 25, 2026 or earthquakes by day.

More from around the world