Earthquake near Seward, AK

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 4 km (2 mi) from the epicentre. In Seward, 15 km away, the estimate is intensity II (weak). 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.

Earthquakes near other towns within 30 km: Bear Creek.

How big was it?

This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
3. Around the size people start to feel M 3.0 180× the energy of this one
4. This earthquake M 1.5 about 5.4 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 4.4 on 2022-07-12 — about 22,000 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

1. 6.6 3 km SW of Bear Creek, Alaska · 18 km NNW of this epicentre Sep 27, 1949
2. 6.3 37 km SSE of Lowell Point, Alaska · 29 km S of this epicentre Mar 28, 1964
3. 6.1 25 km WSW of Chenega, Alaska · 46 km E of this epicentre Mar 28, 1964
4. 6.0 54 km SE of Lowell Point, Alaska · 43 km SSE of this epicentre Mar 28, 1964
5. 5.9 33 km SSE of Lowell Point, Alaska · 24 km SSE of this epicentre Mar 29, 1964

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 60.0090, -149.2645. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.0 22 km SSE of Lowell Point, Alaska 22:21 UTC
2. 2.0 23 km SSE of Lowell Point, Alaska 06:13 UTC
3. 2.5 28 km E of Primrose, Alaska 05:36 UTC
4. 1.6 35 km ESE of Lowell Point, Alaska 02:37 UTC
5. 2.0 20 km SSE of Lowell Point, Alaska 12:52 UTC
6. 2.6 13 km W of Primrose, Alaska 14:33 UTC
7. 2.2 11 km W of Crown Point, Alaska 11:42 UTC
8. 1.8 11 km E of Crown Point, Alaska 23:40 UTC
9. 1.7 14 km W of Lowell Point, Alaska 19:33 UTC
10. 2.2 32 km ESE of Lowell Point, Alaska 07:52 UTC
11. 1.7 31 km SE of Lowell Point, Alaska 18:13 UTC
12. 2.2 14 km SSE of Lowell Point, Alaska 14:20 UTC
13. 2.0 23 km S of Cooper Landing, Alaska 15:08 UTC
14. 1.9 21 km WNW of Bear Creek, Alaska 19:40 UTC
15. 2.0 9 km W of Crown Point, Alaska 06:41 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:11 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.