159 km E of McCarthy, 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, people at rest would likely notice it out to about 97 km (60 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 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 11,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
3. Magna, Utah 2020 M 5.7 350× the energy of this one
4. This earthquake M 4.0 about 15 tons of TNT
5. Around the size people start to feel M 3.0 this one released 32× 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 4.8 on 2023-08-06 — about 16 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

1. 5.7 152 km E of McCarthy, Alaska · 7 km WSW of this epicentre Jun 26, 2001
2. 5.4 140 km SSE of Alcan Border, Alaska · 23 km NW of this epicentre Jun 10, 1972
3. 5.4 136 km SSE of Alcan Border, Alaska · 23 km NNW of this epicentre Mar 30, 1983
4. 5.3 136 km E of McCarthy, Alaska · 25 km WNW of this epicentre Apr 29, 2004
5. 5.2 130 km SSE of Alcan Border, Alaska · 29 km NNW of this epicentre Dec 22, 1969

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 61.3525, -139.9439. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 1.7 135 km ESE of McCarthy, Alaska 22:35 UTC
2. 3.2 152 km SSE of Alcan Border, Alaska 21:46 UTC
3. 3.6 154 km E of McCarthy, Alaska 21:44 UTC
4. 1.7 159 km ESE of McCarthy, Alaska 11:05 UTC
5. 1.6 139 km E of McCarthy, Alaska 04:54 UTC
6. 1.9 140 km E of McCarthy, Alaska 04:26 UTC
7. 1.5 157 km ESE of McCarthy, Alaska 16:48 UTC
8. 2.5 149 km SSE of Alcan Border, Alaska 09:05 UTC
9. 1.6 155 km ESE of McCarthy, Alaska 05:53 UTC
10. 2.5 130 km E of McCarthy, Alaska 22:05 UTC
11. 1.6 142 km E of McCarthy, Alaska 00:26 UTC
12. 1.8 173 km N of Yakutat, Alaska 15:21 UTC
13. 1.6 134 km E of McCarthy, Alaska 09:46 UTC
14. 2.1 134 km ESE of McCarthy, Alaska 16:25 UTC
15. 2.6 159 km N of Yakutat, Alaska 11:58 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:06 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.