240 km SSE of Old Harbor, Alaska

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 89,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
4. This earthquake M 3.4 about 1.9 tons of TNT
5. Around the size people start to feel M 3.0 this one released 4× 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.

Where

Epicentre 55.2579, -151.6359. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.5 229 km SSE of Old Harbor, Alaska 05:26 UTC
2. 2.5 194 km SSE of Old Harbor, Alaska 07:52 UTC
3. 2.8 228 km SSE of Old Harbor, Alaska 11:18 UTC
4. 2.7 282 km SSE of Akhiok, Alaska 17:29 UTC
5. 3.2 203 km SSE of Old Harbor, Alaska 04:02 UTC
6. 2.8 205 km SSE of Old Harbor, Alaska 00:20 UTC
7. 2.4 203 km SSE of Old Harbor, Alaska 02:30 UTC
8. 2.4 218 km SSE of Old Harbor, Alaska 22:32 UTC
9. 3.0 202 km SSE of Old Harbor, Alaska 10:46 UTC
10. 3.5 206 km SSE of Old Harbor, Alaska 04:11 UTC
11. 2.5 218 km SSE of Old Harbor, Alaska 01:36 UTC
12. 2.8 265 km SSE of Akhiok, Alaska 13:07 UTC
13. 2.3 217 km SSE of Old Harbor, Alaska 08:01 UTC
14. 2.2 225 km SSE of Old Harbor, Alaska 05:12 UTC
15. 2.3 253 km SSE of Old Harbor, Alaska 13:02 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:55 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 5.0 on 2020-01-02 — it released about 250 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.