87 km SE of Ugashik, Alaska

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 5 km (3 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 30 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 500,000× the energy of this one
2. Magna, Utah 2020 M 5.7 350,000× the energy of this one
3. Around the size people start to feel M 3.0 32× the energy of this one
4. This earthquake M 2.0 about 30 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 4.6 on 2022-04-10 — about 7,900 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

1. 6.8 117 km SSE of Ugashik, Alaska · 49 km SSW of this epicentre May 29, 2015
2. 5.4 115 km SSE of Ugashik, Alaska · 42 km S of this epicentre Jun 9, 1971
3. 5.4 60 km E of Ugashik, Alaska · 48 km N of this epicentre Sep 26, 1983
4. 5.4 113 km SSE of Ugashik, Alaska · 47 km SSW of this epicentre Jan 27, 2004
5. 5.0 113 km SE of Ugashik, Alaska · 32 km S of this epicentre Dec 30, 2010

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 57.0214, -156.2673. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.0 94 km ESE of Ugashik, Alaska 06:55 UTC
2. 2.1 66 km SE of Ugashik, Alaska 02:09 UTC
3. 2.3 101 km SE of Ugashik, Alaska 03:44 UTC
4. 2.1 88 km SSE of Ugashik, Alaska 12:26 UTC
5. 2.1 87 km WSW of Karluk, Alaska 23:27 UTC
6. 1.8 80 km ESE of Ugashik, Alaska 19:53 UTC
7. 2.1 72 km E of Ugashik, Alaska 20:03 UTC
8. 1.5 72 km ESE of Ugashik, Alaska 01:29 UTC
9. 1.7 62 km ESE of Ugashik, Alaska 23:02 UTC
10. 1.9 80 km SE of Ugashik, Alaska 13:17 UTC
11. 2.2 124 km SSE of Ugashik, Alaska 06:03 UTC
12. 2.0 91 km SSE of Ugashik, Alaska 00:19 UTC
13. 1.5 78 km SE of Ugashik, Alaska 20:47 UTC
14. 1.5 95 km SSE of Ugashik, Alaska 16:49 UTC
15. 1.5 100 km WSW of Karluk, Alaska 13:54 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 11:13 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.