26 km N of Atka, 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 8 km (5 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 6.6 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 2,300,000× the energy of this one
2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
3. Around the size people start to feel M 3.0 140× the energy of this one
4. This earthquake M 1.6 about 6.6 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 5.0 on 2016-11-23 — about 140,000 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

1. 7.1 58 km WNW of Atka, Alaska · 47 km W of this epicentre Feb 28, 1970
2. 6.5 25 km NW of Atka, Alaska · 22 km WSW of this epicentre May 17, 1986
3. 6.4 37 km WNW of Atka, Alaska · 37 km WSW of this epicentre May 15, 1986
4. 5.9 42 km NNW of Atka, Alaska · 22 km WNW of this epicentre Mar 27, 1971
5. 5.6 22 km W of Atka, Alaska · 31 km SW of this epicentre May 15, 1986

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 52.4292, -174.2295. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.6 6 km NNW of Atka, Alaska 18:14 UTC
2. 2.2 31 km ESE of Atka, Alaska 14:25 UTC
3. 3.6 72 km N of Atka, Alaska 07:57 UTC
4. 2.3 31 km WSW of Atka, Alaska 10:14 UTC
5. 3.6 20 km SSE of Atka, Alaska 10:14 UTC
6. 1.9 28 km NNW of Atka, Alaska 14:04 UTC
7. 2.8 51 km NW of Atka, Alaska 02:53 UTC
8. 2.5 12 km ENE of Atka, Alaska 09:12 UTC
9. 2.1 22 km SW of Atka, Alaska 07:23 UTC
10. 1.5 31 km W of Atka, Alaska 06:36 UTC
11. 2.4 15 km SE of Atka, Alaska 11:00 UTC
12. 1.5 18 km NE of Atka, Alaska 00:26 UTC
13. 1.5 28 km W of Atka, Alaska 21:43 UTC
14. 2.1 29 km W of Atka, Alaska 09:56 UTC
15. 2.8 22 km NNW of Atka, Alaska 09:06 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 05:20 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.