186 km SSE of Unalaska, Alaska

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

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.

Where

Epicentre 52.2569, -165.8236. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.2 193 km SSE of Unalaska, Alaska 04:21 UTC
2. 2.9 199 km SSE of Unalaska, Alaska 19:44 UTC
3. 3.1 179 km SSE of Unalaska, Alaska 15:15 UTC
4. 2.9 167 km SSE of Unalaska, Alaska 13:57 UTC
5. 2.7 207 km S of Unalaska, Alaska 16:10 UTC
6. 2.6 191 km S of Unalaska, Alaska 09:11 UTC
7. 3.0 189 km SSE of Unalaska, Alaska 08:48 UTC
8. 2.8 192 km SSE of Unalaska, Alaska 22:14 UTC
9. 3.3 208 km ESE of Nikolski, Alaska 02:23 UTC
10. 2.8 213 km SSE of Unalaska, Alaska 19:35 UTC
11. 3.2 196 km ESE of Nikolski, Alaska 01:27 UTC
12. 2.6 185 km SSE of Unalaska, Alaska 23:18 UTC
13. 2.9 south of the Aleutian Islands 03:46 UTC
14. 2.9 south of the Aleutian Islands 15:37 UTC
15. 2.6 south of the Aleutian Islands 07:44 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 18:27 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 63 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.