124 km E of McCarthy, 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 4 km (2 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
3. Around the size people start to feel M 3.0 45× the energy of this one
4. This earthquake M 1.9 about 21 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 4.9 on 2021-05-09 — about 32,000 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. 6.1 109 km E of McCarthy, Alaska · 31 km SSW of this epicentre Jul 7, 1920
2. 5.7 152 km E of McCarthy, Alaska · 33 km ESE of this epicentre Jun 26, 2001
3. 5.5 87 km ENE of McCarthy, Alaska · 41 km WNW of this epicentre Nov 23, 1987
4. 5.4 140 km SSE of Alcan Border, Alaska · 17 km E of this epicentre Jun 10, 1972
5. 5.4 136 km SSE of Alcan Border, Alaska · 27 km E of this epicentre Mar 30, 1983

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 61.5040, -140.5930. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.1 121 km ESE of McCarthy, Alaska 19:13 UTC
2. 2.1 124 km ESE of McCarthy, Alaska 18:39 UTC
3. 1.5 124 km ESE of McCarthy, Alaska 11:54 UTC
4. 1.7 127 km ESE of McCarthy, Alaska 02:27 UTC
5. 1.7 105 km E of McCarthy, Alaska 06:17 UTC
6. 3.8 137 km E of McCarthy, Alaska 13:26 UTC
7. 1.6 100 km E of McCarthy, Alaska 06:11 UTC
8. 2.0 107 km E of McCarthy, Alaska 15:14 UTC
9. 1.5 98 km E of McCarthy, Alaska 08:38 UTC
10. 1.5 135 km ESE of McCarthy, Alaska 12:47 UTC
11. 1.5 134 km ESE of McCarthy, Alaska 04:22 UTC
12. 1.6 134 km ESE of McCarthy, Alaska 17:24 UTC
13. 1.7 153 km ESE of McCarthy, Alaska 00:05 UTC
14. 1.7 124 km E of McCarthy, Alaska 06:18 UTC
15. 1.6 153 km ESE of McCarthy, Alaska 15:08 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 09:17 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.