147 km SSE of Sand Point, 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 2 km (1 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 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 5.9 on 2020-10-19 — about 180,000 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

1. 5.9 131 km S of Sand Point, Alaska · 34 km WNW of this epicentre Dec 3, 1933
2. 5.0 188 km SSE of Sand Point, Alaska · 42 km S of this epicentre Oct 16, 2001

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 54.0585, -159.9038. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.2 120 km SSE of Sand Point, Alaska 01:52 UTC
2. 2.2 129 km SSE of Sand Point, Alaska 00:51 UTC
3. 2.1 110 km SSE of Sand Point, Alaska 22:05 UTC
4. 2.1 121 km SSE of Sand Point, Alaska 20:36 UTC
5. 2.1 129 km SSE of Sand Point, Alaska 19:44 UTC
6. 2.1 120 km SSE of Sand Point, Alaska 18:02 UTC
7. 2.5 116 km SSE of Sand Point, Alaska 17:45 UTC
8. 3.3 124 km SSE of Sand Point, Alaska 12:58 UTC
9. 2.1 122 km SSE of Sand Point, Alaska 11:05 UTC
10. 2.7 122 km SSE of Sand Point, Alaska 10:22 UTC
11. 2.2 122 km SSE of Sand Point, Alaska 09:20 UTC
12. 2.1 128 km SSE of Sand Point, Alaska 09:13 UTC
13. 3.2 147 km SSE of Sand Point, Alaska 08:40 UTC
14. 2.2 123 km SSE of Sand Point, Alaska 08:25 UTC
15. 2.8 107 km SSE of Sand Point, Alaska 07:23 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:54 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.