183 km SSE of False Pass, Alaska

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

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
3. Around the size people start to feel M 3.0 22× the energy of this one
4. This earthquake M 2.1 about 43 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.

Where

Epicentre 53.3268, -162.3629. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.1 196 km SSE of False Pass, Alaska 01:13 UTC
2. 2.6 206 km SSE of False Pass, Alaska 02:10 UTC
3. 3.6 148 km SSE of False Pass, Alaska 08:10 UTC
4. 3.5 156 km SSE of False Pass, Alaska 09:34 UTC
5. 2.8 208 km SSE of False Pass, Alaska 04:23 UTC
6. 3.1 215 km SSE of False Pass, Alaska 16:12 UTC
7. 2.7 201 km SSE of False Pass, Alaska 04:59 UTC
8. 2.8 212 km SSE of False Pass, Alaska 09:21 UTC
9. 2.3 139 km SSE of False Pass, Alaska 01:56 UTC
10. 2.8 227 km SSE of False Pass, Alaska 18:36 UTC
11. 2.6 226 km SSE of False Pass, Alaska 09:57 UTC
12. 2.6 186 km SSE of False Pass, Alaska 03:46 UTC
13. 3.0 201 km SSE of False Pass, Alaska 04:01 UTC
14. 2.3 212 km SSE of False Pass, Alaska 12:06 UTC
15. 2.5 194 km SSE of False Pass, Alaska 10:57 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:26 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 4.1 on 2017-09-05 — it released about 1,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.