183 km S of Adak, 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 10 km (6 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 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
3. Around the size people start to feel M 3.0 130× the energy of this one
4. This earthquake M 1.6 about 7.6 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 5.4 on 2019-09-09 — about 500,000 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 146 km S of Adak, Alaska · 38 km N of this epicentre Mar 10, 1957
2. 6.2 204 km S of Adak, Alaska · 21 km S of this epicentre Dec 9, 1918
3. 6.1 198 km S of Adak, Alaska · 18 km SW of this epicentre May 22, 1957
4. 6.1 189 km S of Adak, Alaska · 20 km WSW of this epicentre Jul 3, 1960
5. 6.0 194 km SSW of Adak, Alaska · 50 km W of this epicentre Nov 11, 1993

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 50.2284, -176.7507. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.1 222 km S of Adak, Alaska 17:30 UTC
2. 2.6 165 km S of Adak, Alaska 08:14 UTC
3. 2.6 162 km S of Adak, Alaska 01:56 UTC
4. 1.7 166 km SSW of Adak, Alaska 04:49 UTC
5. 2.6 134 km S of Adak, Alaska 09:48 UTC
6. 2.2 184 km S of Adak, Alaska 04:58 UTC
7. 3.6 212 km S of Adak, Alaska 05:03 UTC
8. 2.1 162 km S of Adak, Alaska 11:02 UTC
9. 2.2 199 km S of Adak, Alaska 15:09 UTC
10. 2.7 218 km S of Adak, Alaska 22:55 UTC
11. 4.0 170 km SSW of Adak, Alaska 08:23 UTC
12. 2.6 Andreanof Islands, Aleutian Islands, Alaska 09:05 UTC
13. 2.8 177 km SSW of Adak, Alaska 18:12 UTC
14. 2.5 171 km S of Adak, Alaska 02:23 UTC
15. 2.1 154 km S of Adak, Alaska 02:21 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 08:41 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.