207 km S of Atka, Alaska

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

At this magnitude and depth, people at rest would likely notice it out to about 57 km (35 mi) from the epicentre. 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 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.5 on 2017-01-10 — about 45 times the energy of this one.

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

1. 6.6 208 km S of Atka, Alaska · 43 km W of this epicentre Apr 30, 1913
2. 6.0 234 km SSE of Atka, Alaska · 29 km SE of this epicentre Nov 9, 1929
3. 5.6 198 km SSE of Atka, Alaska · 35 km ENE of this epicentre Mar 7, 2015
4. 5.5 232 km SSE of Atka, Alaska · 44 km ESE of this epicentre Jul 13, 1981
5. 5.4 198 km SSE of Atka, Alaska · 16 km NE of this epicentre Feb 20, 2013

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 50.3545, -173.7253. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.1 195 km S of Atka, Alaska 15:29 UTC
2. 2.8 205 km S of Atka, Alaska 19:55 UTC
3. 2.9 164 km S of Atka, Alaska 16:26 UTC
4. 3.2 205 km S of Atka, Alaska 06:54 UTC
5. 3.1 180 km SSE of Atka, Alaska 04:53 UTC
6. 3.1 185 km S of Atka, Alaska 04:37 UTC
7. 2.9 181 km S of Atka, Alaska 04:50 UTC
8. 2.9 235 km SSE of Atka, Alaska 00:22 UTC
9. 3.8 211 km SSE of Atka, Alaska 22:35 UTC
10. 3.4 192 km S of Atka, Alaska 16:24 UTC
11. 3.0 208 km S of Atka, Alaska 22:11 UTC
12. 2.9 204 km SSE of Atka, Alaska 22:38 UTC
13. 2.3 226 km SSE of Atka, Alaska 09:39 UTC
14. 3.5 209 km SSE of Atka, Alaska 06:15 UTC
15. 4.4 213 km SSE of Atka, Alaska 09:52 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:33 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.