202 km SSE of Unalaska, 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 52.2542, -165.1611. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.6 189 km SSE of Unalaska, Alaska 23:18 UTC
2. 2.8 172 km SSE of Unalaska, Alaska 15:08 UTC
3. 2.7 182 km SSE of Unalaska, Alaska 19:43 UTC
4. 2.8 189 km SSE of Unalaska, Alaska 11:42 UTC
5. 3.5 175 km SE of Unalaska, Alaska 14:10 UTC
6. 2.6 189 km SSE of Unalaska, Alaska 07:16 UTC
7. 2.4 184 km SSE of Unalaska, Alaska 08:45 UTC
8. 2.9 207 km SSE of Unalaska, Alaska 13:34 UTC
9. 2.4 200 km SSE of Unalaska, Alaska 08:34 UTC
10. 2.2 208 km SSE of Unalaska, Alaska 16:48 UTC
11. 2.2 230 km SSE of Unalaska, Alaska 06:52 UTC
12. 2.2 219 km SSE of Unalaska, Alaska 11:40 UTC
13. 2.8 193 km SSE of Unalaska, Alaska 20:13 UTC
14. 2.5 181 km SSE of Unalaska, Alaska 09:38 UTC
15. 2.2 197 km SSE of Unalaska, Alaska 13:42 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 15:41 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 5.2 on 2019-08-03 — it released about 500 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.