Earthquake near Fishhook, AK

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 28 km (17 mi) from the epicentre. In Fishhook, 16 km away, the estimate is intensity II (weak). 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.

Likely felt in: Fishhook 16 km, intensity II · Tanaina 25 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
3. Around the size people start to feel M 3.0 1.4× the energy of this one
4. This earthquake M 2.9 about 680 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 5.1 on 2020-11-07 — about 2,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

1. 5.9 23 km NE of Willow, Alaska · 17 km WNW of this epicentre Jan 1, 1975
2. 5.8 14 km NNE of Fishhook, Alaska · 17 km E of this epicentre Aug 14, 1984
3. 5.6 11 km NW of Big Lake, Alaska · 47 km SW of this epicentre Oct 7, 1966
4. 5.4 25 km NNW of Willow, Alaska · 39 km WNW of this epicentre May 10, 1962
5. 5.3 3 km NNE of Houston, Alaska · 28 km SW of this epicentre Sep 1, 1966

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 61.8540, -149.4360. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.1 12 km S of Susitna North, Alaska 08:20 UTC
2. 2.1 4 km NNE of Big Lake, Alaska 08:47 UTC
3. 2.2 12 km W of Fishhook, Alaska 09:29 UTC
4. 1.9 16 km WNW of Fishhook, Alaska 22:08 UTC
5. 1.6 10 km E of Willow, Alaska 15:03 UTC
6. 1.3 20 km NNE of Fishhook, Alaska 11:51 UTC
7. 2.0 24 km NW of Fishhook, Alaska 01:14 UTC
8. 1.7 15 km N of Meadow Lakes, Alaska 15:17 UTC
9. 2.0 29 km ESE of Susitna North, Alaska 13:58 UTC
10. 1.8 26 km NW of Fishhook, Alaska 12:34 UTC
11. 1.9 4 km NNE of Susitna North, Alaska 08:59 UTC
12. 1.5 26 km ENE of Susitna North, Alaska 20:31 UTC
13. 1.7 3 km ENE of Big Lake, Alaska 16:15 UTC
14. 3.6 2 km NW of Knik, Alaska 14:49 UTC
15. 1.7 7 km SE of Houston, Alaska 13:51 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 15:45 UTC. 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.

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.