223 km S of Sand Point, Alaska

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

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
3. Around the size people start to feel M 3.0 4× the energy of this one
4. This earthquake M 2.6 about 240 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 5.5 on 2020-07-05 — about 22,000 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

1. 5.7 208 km SSE of Sand Point, Alaska · 24 km NE of this epicentre May 17, 1964
2. 5.5 241 km S of Sand Point, Alaska · 29 km SW of this epicentre May 23, 1969
3. 5.5 233 km S of Sand Point, Alaska · 10 km SSE of this epicentre May 20, 1972
4. 5.3 232 km SSE of King Cove, Alaska · 43 km WSW of this epicentre Jun 18, 2006
5. 5.0 188 km SSE of Sand Point, Alaska · 38 km NNE of this epicentre Oct 16, 2001

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 53.3492, -160.0215. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.3 218 km S of Sand Point, Alaska 06:57 UTC
2. 3.6 193 km S of Sand Point, Alaska 21:15 UTC
3. 2.8 south of Alaska 13:30 UTC
4. 2.3 220 km S of Sand Point, Alaska 18:53 UTC
5. 2.7 227 km S of Sand Point, Alaska 06:00 UTC
6. 2.1 219 km S of Sand Point, Alaska 13:34 UTC
7. 2.5 236 km S of Sand Point, Alaska 20:20 UTC
8. 3.8 237 km S of Sand Point, Alaska 13:53 UTC
9. 3.1 234 km S of Sand Point, Alaska 11:11 UTC
10. 5.4 219 km S of Sand Point, Alaska 10:02 UTC
11. 5.0 214 km SSE of Sand Point, Alaska 10:41 UTC
12. 2.5 south of Alaska 02:37 UTC
13. 2.4 194 km SSE of Sand Point, Alaska 22:33 UTC
14. 3.0 230 km S of Sand Point, Alaska 01:00 UTC
15. 3.0 220 km SSE of Sand Point, Alaska 05:08 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 19:38 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.