62 km SSE of Adak, Alaska

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 7 km (4 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 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
3. Around the size people start to feel M 3.0 89× the energy of this one
4. This earthquake M 1.7 about 11 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 2017-04-04 — about 710,000 times the energy of this one.

Before 2016, the USGS record lists 140 earthquakes of M5 or more within 50 km; the five largest:

1. 7.3 46 km SSW of Adak, Alaska · 38 km WNW of this epicentre Jun 10, 1996
2. 7.1 75 km S of Adak, Alaska · 32 km WSW of this epicentre Mar 14, 1957
3. 7.0 101 km S of Adak, Alaska · 41 km S of this epicentre Sep 9, 1910
4. 6.9 61 km SSW of Adak, Alaska · 35 km W of this epicentre Feb 7, 1971
5. 6.7 76 km SSE of Adak, Alaska · 15 km SE of this epicentre Dec 10, 1905

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 51.3453, -176.3425. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 1.9 60 km S of Adak, Alaska 05:50 UTC
2. 1.8 64 km S of Adak, Alaska 05:42 UTC
3. 2.6 69 km SE of Adak, Alaska 23:46 UTC
4. 2.6 70 km SE of Adak, Alaska 09:56 UTC
5. 2.9 33 km S of Adak, Alaska 11:15 UTC
6. 1.9 45 km S of Adak, Alaska 02:24 UTC
7. 1.7 20 km SSE of Adak, Alaska 23:06 UTC
8. 2.1 48 km SSE of Adak, Alaska 11:19 UTC
9. 2.5 52 km SSE of Adak, Alaska 09:37 UTC
10. 1.9 35 km SSW of Adak, Alaska 07:13 UTC
11. 3.5 51 km S of Adak, Alaska 02:36 UTC
12. 2.5 36 km S of Adak, Alaska 07:24 UTC
13. 1.6 37 km S of Adak, Alaska 02:22 UTC
14. 1.8 47 km SE of Adak, Alaska 23:19 UTC
15. 1.9 64 km S of Adak, Alaska 01:51 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 02:45 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.