110 km NW of False Pass, Alaska

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

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 43 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 4,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 180× the energy of this one
3. Magna, Utah 2020 M 5.7 130× the energy of this one
4. This earthquake M 4.3 about 43 tons of TNT
5. Around the size people start to feel M 3.0 this one released 89× 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. 5.5 66 km NNW of False Pass, Alaska · 48 km SE of this epicentre Jul 14, 1994
2. 5.3 133 km NW of False Pass, Alaska · 40 km W of this epicentre Aug 5, 1971

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 55.6700, -164.4083. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.6 117 km NW of False Pass, Alaska 17:19 UTC
2. 3.1 105 km NW of Cold Bay, Alaska 03:31 UTC
3. 4.0 77 km NNW of False Pass, Alaska 18:43 UTC
4. 2.6 91 km NW of False Pass, Alaska 09:14 UTC
5. 2.6 100 km NNW of False Pass, Alaska 01:23 UTC
6. 2.8 79 km WNW of False Pass, Alaska 19:34 UTC
7. 3.5 88 km NW of False Pass, Alaska 14:40 UTC
8. 2.9 106 km NW of False Pass, Alaska 04:35 UTC
9. 3.0 96 km NW of Cold Bay, Alaska 00:35 UTC
10. 2.8 64 km NW of False Pass, Alaska 20:48 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 06:14 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.