EARTHQUAKEM4.3

M4.3 earthquake near Kasilof, Alaska

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

A magnitude 4.3 earthquake struck 24 km (15 mi) southeast of Kasilof, Alaska on Sunday, November 1, 2026 at 11:30 UTC, at a depth of 70 km (44 mi), according to the U.S. Geological Survey. At this intermediate depth, shaking spreads out before it reaches the surface.

USGS set its tsunami flag for this earthquake. The flag is set automatically for large earthquakes at sea and is not a warning. For official tsunami information, see tsunami.gov and your national warning center.

USGS’s PAGER impact estimate is GREEN: little or no damage expected.

87 people reported feeling it to USGS “Did You Feel It?”.

MagnitudeM4.3
Depth70 km (44 mi)
Time (UTC)Nov 1 11:30
Location60.20°N 150.93°W
Nearest townKasilof · 24 km
Energy43 tons TNT
Tsunami flagSet (not a warning)
PAGER alertGREEN
Felt reports87
See it on the live 3D globe →Watch live on YouTube🔔 Get alerts near you

Why here?

This earthquake struck 70 km (44 mi) down, about 303 km (188 mi) from the nearest plate boundary on the surface. Quakes this deep happen inside old ocean plate that has sunk far into the mantle at a subduction zone, long after it dove beneath its neighbor. Their great depth spreads the shaking over a wide area but usually keeps it gentle at the surface.

The red lines on the map are plate boundaries.

What kind of fault?

USGS’s analysis of the seismic waves shows it was an oblique earthquake: the fault slipped partly sideways and partly as one block pushed up over the other.

Shaking and impact

The strongest shaking USGS estimates was intensity 3 on the Modified Mercalli scale: weak. USGS’s PAGER system estimates it most likely caused no deaths (95 percent probability). Early estimates are revised as reports come in.

How strong was it?

Magnitude is logarithmic: each whole step releases about 32 times more energy. This magnitude 4.3 released roughly the energy of 43 tons of TNT. That is about 2.8 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 63,000,000 times more than this one.

Earthquake history here

Before this earthquake, USGS had recorded 60 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 November 1, 2026 or earthquakes by day.

More from around the world