25 km SSW of Nanwalek, Alaska

A magnitude 1.8 earthquake was recorded 25 km SSW of Nanwalek, Alaska at 07:39 UTC on 2026-09-29. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
3. Around the size people start to feel M 3.0 63× the energy of this one
4. This earthquake M 1.8 about 15 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 5.8 on 2019-05-27 — about 1,000,000 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 25 km NW of Nanwalek, Alaska · 42 km NNW of this epicentre Jun 24, 1963
2. 6.0 61 km WSW of Nanwalek, Alaska · 49 km W of this epicentre Dec 5, 1942
3. 5.8 63 km WSW of Nanwalek, Alaska · 48 km W of this epicentre May 19, 2000
4. 5.7 30 km ESE of Port Graham, Alaska · 42 km ENE of this epicentre May 5, 1999
5. 5.5 6 km WNW of Nanwalek, Alaska · 27 km N of this epicentre Feb 10, 2004

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 59.1350, -152.0550. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 1.8 17 km SSW of Nanwalek, Alaska 08:16 UTC
2. 1.9 33 km WSW of Nanwalek, Alaska 18:30 UTC
3. 3.4 23 km NW of Nanwalek, Alaska 03:29 UTC
4. 1.9 42 km WSW of Nanwalek, Alaska 09:37 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 01:39 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.