140 km ESE of Atka, Alaska

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

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
2. Magna, Utah 2020 M 5.7 89,000× the energy of this one
3. Around the size people start to feel M 3.0 7.9× the energy of this one
4. This earthquake M 2.4 about 120 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 2023-11-03 — about 7,900 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

1. 7.3 Fox Islands, Aleutian Islands, Alaska · 28 km ENE of this epicentre Jun 24, 2011
2. 6.9 170 km E of Atka, Alaska · 42 km NE of this epicentre Sep 2, 2011
3. 6.5 143 km ESE of Atka, Alaska · 20 km S of this epicentre Oct 14, 1960
4. 6.3 143 km E of Atka, Alaska · 10 km NNE of this epicentre Apr 5, 1957
5. 6.1 185 km ESE of Atka, Alaska · 44 km E of this epicentre Dec 6, 1930

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 51.9327, -172.1922. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.1 120 km ESE of Atka, Alaska 03:12 UTC
2. 3.0 117 km ESE of Atka, Alaska 10:49 UTC
3. 3.4 106 km E of Atka, Alaska 05:05 UTC
4. 2.9 119 km ESE of Atka, Alaska 07:43 UTC
5. 3.1 118 km ESE of Atka, Alaska 07:22 UTC
6. 3.6 130 km E of Atka, Alaska 07:54 UTC
7. 2.6 150 km E of Atka, Alaska 20:46 UTC
8. 3.3 136 km ESE of Atka, Alaska 18:08 UTC
9. 3.8 138 km E of Atka, Alaska 14:35 UTC
10. 3.2 114 km ESE of Atka, Alaska 02:31 UTC
11. 3.4 169 km E of Atka, Alaska 15:37 UTC
12. 2.8 104 km E of Atka, Alaska 09:38 UTC
13. 3.2 116 km E of Atka, Alaska 05:33 UTC
14. 3.2 130 km ESE of Atka, Alaska 06:42 UTC
15. 3.7 127 km E of Atka, Alaska 16:45 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 10:17 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.