Earthquake near Sand Point, AK

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. In Sand Point, 18 km away, the estimate is intensity II (weak). 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 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
3. Around the size people start to feel M 3.0 1.4× the energy of this one
4. This earthquake M 2.9 about 680 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 5.6 on 2020-07-29 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

1. 6.9 17 km S of Sand Point, Alaska · 10 km E of this epicentre May 13, 1993
2. 6.2 35 km S of Sand Point, Alaska · 19 km SSE of this epicentre May 25, 1993
3. 6.1 39 km SW of Sand Point, Alaska · 26 km WSW of this epicentre May 17, 1948
4. 6.0 58 km SW of Sand Point, Alaska · 41 km SW of this epicentre Feb 12, 1940
5. 6.0 15 km SSE of Sand Point, Alaska · 12 km E of this epicentre Aug 28, 1952

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 55.1827, -160.6129. Map © OpenStreetMap contributors.

Nearby places

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

1. 1.7 64 km SW of Sand Point, Alaska 11:53 UTC
2. 1.7 38 km SW of Sand Point, Alaska 04:01 UTC
3. 3.0 38 km WSW of Sand Point, Alaska 22:17 UTC
4. 1.7 25 km N of Sand Point, Alaska 11:55 UTC
5. 1.9 66 km S of Sand Point, Alaska 11:31 UTC
6. 1.7 17 km S of Sand Point, Alaska 15:11 UTC
7. 1.5 61 km S of Sand Point, Alaska 06:27 UTC
8. 2.0 5 km NNE of Sand Point, Alaska 08:04 UTC
9. 2.1 4 km NE of Sand Point, Alaska 07:11 UTC
10. 2.1 9 km NNE of Sand Point, Alaska 06:41 UTC
11. 2.3 5 km NE of Sand Point, Alaska 15:32 UTC
12. 1.6 58 km SSW of Sand Point, Alaska 09:15 UTC
13. 2.8 7 km E of Sand Point, Alaska 03:06 UTC
14. 1.7 4 km NE of Sand Point, Alaska 01:29 UTC
15. 2.0 10 km NE of Sand Point, Alaska 23:40 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:28 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.