148 km SSE of King Cove, 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 19 km (12 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 5.7 on 2017-05-28 — about 89,000 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 109 km SSE of King Cove, Alaska · 38 km NNW of this epicentre Nov 6, 1941
2. 6.4 159 km SSE of King Cove, Alaska · 13 km S of this epicentre May 25, 2002
3. 6.2 141 km SSE of King Cove, Alaska · 7 km NNW of this epicentre Nov 8, 1951
4. 6.1 166 km SSE of King Cove, Alaska · 41 km SW of this epicentre Apr 22, 1956
5. 5.9 146 km SSE of King Cove, Alaska · 35 km WSW of this epicentre Apr 21, 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 53.9339, -161.0959. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.5 112 km S of Sand Point, Alaska 01:55 UTC
2. 2.2 149 km SSE of King Cove, Alaska 21:30 UTC
3. 2.4 100 km SSE of King Cove, Alaska 12:33 UTC
4. 2.4 133 km S of Sand Point, Alaska 21:46 UTC
5. 3.0 127 km SSW of Sand Point, Alaska 12:13 UTC
6. 2.0 162 km SSE of King Cove, Alaska 13:17 UTC
7. 2.4 109 km SE of King Cove, Alaska 20:55 UTC
8. 2.9 98 km SE of King Cove, Alaska 08:45 UTC
9. 2.0 128 km S of Sand Point, Alaska 17:04 UTC
10. 1.8 115 km S of Sand Point, Alaska 21:20 UTC
11. 2.9 183 km SSE of King Cove, Alaska 12:19 UTC
12. 2.2 127 km S of Sand Point, Alaska 08:07 UTC
13. 2.4 169 km SSE of King Cove, Alaska 20:56 UTC
14. 1.7 101 km SE of King Cove, Alaska 20:31 UTC
15. 4.5 140 km SSE of King Cove, Alaska 01:09 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 02:14 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.