45 km E of Port Alsworth, Alaska

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes 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 7.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 22,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 1,000× the energy of this one
3. Magna, Utah 2020 M 5.7 710× the energy of this one
4. This earthquake M 3.8 about 7.6 tons of TNT
5. Around the size people start to feel M 3.0 this one released 16× 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 since 2016 was M 4.7 on 2016-05-01 — about 22 times the energy of this one.

Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 75 km WNW of Ninilchik, Alaska · 31 km E of this epicentre Feb 7, 1988
2. 6.4 52 km ENE of Pedro Bay, Alaska · 46 km SSE of this epicentre Jul 29, 2015
3. 6.2 70 km E of Port Alsworth, Alaska · 29 km ESE of this epicentre Dec 17, 1968
4. 6.1 73 km WNW of Ninilchik, Alaska · 40 km ENE of this epicentre Jul 9, 1998
5. 5.9 66 km ENE of Pedro Bay, Alaska · 39 km SE of this epicentre Nov 20, 1993

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 60.2765, -153.5092. Map © OpenStreetMap contributors.

Nearby places

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

1. 1.8 49 km ENE of Pedro Bay, Alaska 12:43 UTC
2. 2.3 50 km ESE of Port Alsworth, Alaska 21:56 UTC
3. 3.1 64 km E of Port Alsworth, Alaska 01:47 UTC
4. 1.7 53 km ENE of Pedro Bay, Alaska 22:19 UTC
5. 1.8 38 km NE of Pedro Bay, Alaska 21:30 UTC
6. 2.1 60 km E of Port Alsworth, Alaska 10:56 UTC
7. 2.9 65 km ENE of Pedro Bay, Alaska 10:05 UTC
8. 2.2 51 km E of Port Alsworth, Alaska 08:52 UTC
9. 2.1 60 km ENE of Pedro Bay, Alaska 03:04 UTC
10. 2.0 58 km E of Port Alsworth, Alaska 22:06 UTC
11. 3.6 43 km ESE of Port Alsworth, Alaska 05:37 UTC
12. 2.2 38 km NE of Pedro Bay, Alaska 17:11 UTC
13. 2.0 56 km ENE of Pedro Bay, Alaska 13:07 UTC
14. 2.1 50 km NE of Pedro Bay, Alaska 10:00 UTC
15. 1.9 68 km E of Port Alsworth, Alaska 06:31 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:17 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.