QuakeIndex

Earthquake · reviewed by a seismologist

M 4.6mb

194 km SE of Attu Station, Alaska

Yes. A magnitude 4.6 earthquake was recorded 194 km SE of Attu Station, Alaska at 14:29 UTC on 2026-10-12, 10 km deep. No felt reports to USGS yet.

· 10 km deep · released about 120 tons of TNT

10 km30 km60 km120 km N
Distance rings around the epicentre, with the nearest towns at their true direction. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 4.6 (mb)
Depth
10 km below the surface
Felt
no reports yet
Measured shaking
intensity II (ShakeMap)
Nearest mapped fault
Alaska-Aleutian subduction zone, 23 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2 hours ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 149 km (93 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 120 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 1,400× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 63× the energy of this one
  3. Magna, Utah 2020 M 5.7 45× the energy of this one
  4. This earthquake M 4.6 about 120 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 250× more

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.

Before 2016, the USGS record lists 37 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 238 km SSE of Attu Station, Alaska · 48 km S of this epicentre
  2. 6.6 201 km SE of Attu Station, Alaska · 8 km S of this epicentre
  3. 6.3 196 km SE of Attu Station, Alaska · 36 km NE of this epicentre
  4. 6.0 185 km SE of Attu Station, Alaska · 28 km NNE of this epicentre
  5. 6.0 152 km SE of Attu Station, Alaska · 42 km NNW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 51.4264, 174.8342. Map © OpenStreetMap contributors.

Aftershocks so far

No further earthquakes have been recorded within 50 km since this one.

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

What changedFromToWhen
measured intensity2.222.27
measured intensity2.232.22

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.