35 km W of Susitna, Alaska

76 km (47 mi) WNW of Anchorage, AK

2026-09-28 08:02 UTC · 19 km deep · released about 1.9 lb of TNT

Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.

When: 2026-09-28 08:02 UTC
Magnitude: M 1.2 (ml)
Depth: 19 km below the surface
Felt: no reports yet
Nearest: Anchorage Municipality, 108 km ESE
Nearest mapped fault: Castle Mountain fault, 22 km from its surface trace — near is not the same as on
Status: Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS 5 days ago · we first saw it 5 days ago

A magnitude 1.2 earthquake was recorded 35 km W of Susitna, Alaska at 08:02 UTC on 2026-09-28. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 1.9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.2 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 7,900,000× the energy of this one
Magna, Utah 2020 M 5.7 5,600,000× the energy of this one
Around the size people start to feel M 3.0 500× the energy of this one
This earthquake M 1.2 about 1.9 lb of TNT

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 since 2016 was M 6.0 on 2025-11-27 — about 16,000,000 times the energy of this one.

Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:

6.9 27 km SE of Skwentna, Alaska · 33 km NNE of this epicentre Nov 3, 1943
6.8 Southern Alaska · 48 km S of this epicentre Apr 27, 1933
6.8 4 km NE of Beluga, Alaska · 40 km SSE of this epicentre Oct 23, 1936
6.0 Southern Alaska · 43 km SW of this epicentre Jun 13, 1933
5.8 17 km NW of Beluga, Alaska · 34 km SSW of this epicentre Jun 12, 1933

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

Map loads when it scrolls into view

Epicentre 61.5220, -151.1730. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction from the epicentre
Anchorage Municipality, AK	108 km (67 mi)	ESE	earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK	120 km (75 mi)	NE	earthquakes near Matanuska-Susitna Borough

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

6 earthquakes have been recorded within 50 km since this one.

2.4 24 km ENE of Beluga, Alaska 17:25 UTC
0.7 44 km NNW of Beluga, Alaska 08:08 UTC
0.6 43 km NNW of Beluga, Alaska 10:37 UTC
2.7 23 km SSW of Susitna, Alaska 21:22 UTC
1.9 42 km W of Susitna, Alaska 16:39 UTC
2.5 23 km SSW of Susitna, Alaska 09:29 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 01:40 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

The official USGS event page — the source of record for every value above
Did you feel it? Report it to USGS — reports go to USGS, not to us
ShakeMap for this event, when USGS has produced one

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