58 km E of Port Alsworth, Alaska

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

At this magnitude and depth, people at rest would likely notice it out to about 291 km (181 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 11 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.9 would have released about 32 times as much.

1. Ridgecrest, California 2019 M 7.1 63× the energy of this one
2. Loma Prieta, California 1989 M 6.9 32× the energy of this one
3. Northridge, California 1994 M 6.7 16× the energy of this one
4. This earthquake M 5.9 about 11 kilotons of TNT
5. Mineral, Virginia 2011 M 5.8 this one released 1.4× more
6. Magna, Utah 2020 M 5.7 this one released 2× 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. The previous largest was M 5.6 on 2018-11-21.

Before 2016, the USGS record lists 27 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 75 km WNW of Ninilchik, Alaska · 25 km NE of this epicentre Feb 7, 1988
2. 6.4 52 km ENE of Pedro Bay, Alaska · 26 km S of this epicentre Jul 29, 2015
3. 6.2 70 km E of Port Alsworth, Alaska · 12 km ENE of this epicentre Dec 17, 1968
4. 6.1 73 km WNW of Ninilchik, Alaska · 38 km NE of this epicentre Jul 9, 1998
5. 6.0 53 km W of Anchor Point, Alaska · 45 km SE of this epicentre Apr 18, 1970

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 60.1237, -153.2742. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.3 59 km E of Pedro Bay, Alaska 14:49 UTC
2. 1.5 57 km E of Pedro Bay, Alaska 11:39 UTC
3. 1.8 58 km WNW of Anchor Point, Alaska 22:49 UTC
4. 1.9 73 km WNW of Happy Valley, Alaska 08:54 UTC
5. 2.4 36 km NE of Pedro Bay, Alaska 04:57 UTC
6. 2.1 34 km ENE of Pedro Bay, Alaska 23:42 UTC
7. 2.4 49 km E of Port Alsworth, Alaska 09:07 UTC
8. 1.8 66 km ENE of Pedro Bay, Alaska 06:36 UTC
9. 2.1 56 km NE of Pedro Bay, Alaska 17:30 UTC
10. 1.9 33 km E of Pedro Bay, Alaska 02:02 UTC
11. 2.5 30 km E of Pedro Bay, Alaska 23:47 UTC
12. 2.2 43 km ENE of Pedro Bay, Alaska 21:45 UTC
13. 1.7 32 km E of Pedro Bay, Alaska 15:45 UTC
14. 1.8 41 km ENE of Pedro Bay, Alaska 09:52 UTC
15. 1.7 61 km WNW of Happy Valley, Alaska 09:22 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:51 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.