132 km S of Sand Point, Alaska

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

At this magnitude and depth, people at rest would likely notice it out to about 218 km (135 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 950 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.2 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 180× the energy of this one
2. Mineral, Virginia 2011 M 5.8 7.9× the energy of this one
3. Magna, Utah 2020 M 5.7 5.6× the energy of this one
4. This earthquake M 5.2 about 950 tons of TNT
5. Around the size people start to feel M 3.0 this one released 2,000× more

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 (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.

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 · 16 km W of this epicentre Dec 3, 1933
2. 5.5 137 km S of Sand Point, Alaska · 48 km W of this epicentre Jul 24, 1979

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 54.1646, -160.1539. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 4.3 102 km S of Sand Point, Alaska 05:42 UTC
2. 1.6 105 km SSE of Sand Point, Alaska 23:26 UTC
3. 2.4 154 km SSE of Sand Point, Alaska 20:11 UTC
4. 2.2 112 km S of Sand Point, Alaska 21:26 UTC
5. 2.1 137 km SSE of Sand Point, Alaska 07:47 UTC
6. 2.2 106 km SSE of Sand Point, Alaska 23:41 UTC
7. 2.0 131 km S of Sand Point, Alaska 20:35 UTC
8. 2.2 140 km S of Sand Point, Alaska 10:00 UTC
9. 2.1 92 km S of Sand Point, Alaska 13:36 UTC
10. 2.4 137 km S of Sand Point, Alaska 15:41 UTC
11. 2.4 152 km S of Sand Point, Alaska 11:08 UTC
12. 2.0 143 km S of Sand Point, Alaska 09:30 UTC
13. 2.4 155 km S of Sand Point, Alaska 05:09 UTC
14. 2.7 137 km S of Sand Point, Alaska 18:26 UTC
15. 2.8 155 km S of Sand Point, Alaska 01:21 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 21:46 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.