101 km ESE of Sand Point, Alaska

This was a strong earthquake. Damage is likely near the epicentre and it is felt over a wide area. 5 people have reported feeling it to USGS.

How big was it?

This earthquake released about 21 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 7.1 would have released about 32 times as much.

1. Ridgecrest, California 2019 M 7.1 32× the energy of this one
2. Loma Prieta, California 1989 M 6.9 16× the energy of this one
3. Northridge, California 1994 M 6.7 7.9× the energy of this one
4. This earthquake M 6.1 about 21 kilotons of TNT
5. Mineral, Virginia 2011 M 5.8 this one released 2.8× more
6. Magna, Utah 2020 M 5.7 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 54.9690, -159.0413. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.2 120 km ESE of Sand Point, Alaska 23:48 UTC
2. 1.8 62 km ESE of Sand Point, Alaska 22:11 UTC
3. 2.1 92 km SSE of Perryville, Alaska 22:04 UTC
4. 5.5 73 km S of Ivanof Bay, Alaska 21:39 UTC
5. 1.6 63 km ESE of Sand Point, Alaska 20:51 UTC
6. 2.0 63 km S of Perryville, Alaska 19:45 UTC
7. 4.0 94 km SSE of Perryville, Alaska 19:37 UTC
8. 1.9 64 km ESE of Sand Point, Alaska 19:10 UTC
9. 2.2 64 km ESE of Sand Point, Alaska 18:12 UTC
10. 1.8 66 km ESE of Sand Point, Alaska 17:36 UTC
11. 2.2 80 km ESE of Sand Point, Alaska 17:19 UTC
12. 2.0 74 km S of Perryville, Alaska 17:07 UTC
13. 2.5 138 km SSE of Perryville, Alaska 16:52 UTC
14. 2.0 77 km S of Perryville, Alaska 16:37 UTC
15. 1.6 75 km ESE of Sand Point, Alaska 15:57 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:15 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 7.8 on 2020-07-22 — it released about 350 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.