124 km SSE of Perryville, 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 30 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 500,000× the energy of this one
2. Magna, Utah 2020 M 5.7 350,000× the energy of this one
3. Around the size people start to feel M 3.0 32× the energy of this one
4. This earthquake M 2.0 about 30 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 7.8 on 2020-07-22 — about 500,000,000 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

1. 6.6 104 km SSE of Perryville, Alaska · 23 km NNE of this epicentre Nov 11, 1938
2. 6.5 94 km ESE of Sand Point, Alaska · 32 km WNW of this epicentre Feb 14, 1983
3. 5.9 113 km SE of Sand Point, Alaska · 39 km WSW of this epicentre Jun 7, 1917
4. 5.9 90 km ESE of Sand Point, Alaska · 37 km WNW of this epicentre Feb 14, 1983
5. 5.5 83 km ESE of Sand Point, Alaska · 44 km WNW of this epicentre Jun 23, 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 54.8151, -158.7277. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.7 102 km SSE of Perryville, Alaska 16:28 UTC
2. 2.2 92 km S of Perryville, Alaska 18:05 UTC
3. 2.4 118 km SSE of Perryville, Alaska 16:27 UTC
4. 2.7 103 km SE of Sand Point, Alaska 06:43 UTC
5. 2.1 124 km SE of Sand Point, Alaska 22:11 UTC
6. 2.6 141 km SSE of Perryville, Alaska 22:00 UTC
7. 2.0 122 km ESE of Sand Point, Alaska 20:51 UTC
8. 2.0 121 km SSE of Perryville, Alaska 10:36 UTC
9. 2.7 113 km SSE of Perryville, Alaska 02:22 UTC
10. 2.8 127 km SSE of Perryville, Alaska 01:34 UTC
11. 2.4 106 km SSE of Perryville, Alaska 19:35 UTC
12. 1.8 88 km SSE of Perryville, Alaska 12:20 UTC
13. 3.2 104 km SSE of Perryville, Alaska 12:16 UTC
14. 1.6 100 km SSE of Perryville, Alaska 12:13 UTC
15. 2.4 Alaska Peninsula 11:14 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 14:51 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.