126 km SSW of Unalaska, Alaska

Yes. A magnitude 1.8 earthquake was recorded 126 km SSW of Unalaska, Alaska, at 2:37 am AKDT on 15 August 2017 (10:37 UTC), 66 km deep.

2017-08-15 10:37 UTC · 66 km deep · released about 15 lb of TNT

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Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.

When: 2017-08-15 10:37 UTC
Magnitude: M 1.8 (ml)
Depth: 66 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1193 days ago · we first saw it 1193 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
Magna, Utah 2020 M 5.7 710,000× the energy of this one
Around the size people start to feel M 3.0 63× the energy of this one
This earthquake M 1.8 about 15 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 5.4 on 2016-07-26 — about 250,000 times the energy of this one.

Before 2016, the USGS record lists 52 earthquakes of M5 or more within 50 km; the five largest:

6.5 127 km E of Nikolski, Alaska · 6 km W of this epicentre Oct 13, 2009
6.4 118 km E of Nikolski, Alaska · 15 km W of this epicentre Mar 15, 1957
6.4 123 km ESE of Nikolski, Alaska · 22 km SW of this epicentre Oct 13, 2009
6.3 136 km ESE of Nikolski, Alaska · 14 km S of this epicentre Jan 12, 1952
6.3 Fox Islands, Aleutian Islands, Alaska · 26 km SW of this epicentre Jun 4, 1958

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

Map loads when it scrolls into view

Aftershocks so far

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

2.1 150 km ESE of Nikolski, Alaska 21:20 UTC
2.1 85 km SSW of Unalaska, Alaska 12:26 UTC
2.1 87 km SSW of Unalaska, Alaska 05:43 UTC
2.2 87 km SSW of Unalaska, Alaska 01:59 UTC
3.3 90 km S of Unalaska, Alaska 17:03 UTC
2.2 84 km SSW of Unalaska, Alaska 23:32 UTC
2.1 92 km S of Unalaska, Alaska 20:10 UTC
3.7 90 km SSW of Unalaska, Alaska 20:06 UTC
2.3 87 km SSW of Unalaska, Alaska 20:04 UTC
3.1 84 km S of Unalaska, Alaska 06:17 UTC
2.2 132 km S of Unalaska, Alaska 20:45 UTC
1.8 Fox Islands, Aleutian Islands, Alaska 18:50 UTC
2.4 80 km S of Unalaska, Alaska 23:25 UTC
2.1 85 km S of Unalaska, Alaska 17:42 UTC
2.5 102 km E of Nikolski, Alaska 07:58 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 11:23 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.