109 km SE of Perryville, Alaska

Yes. A magnitude 1.9 earthquake was recorded 109 km SE of Perryville, Alaska at 00:30 UTC on 2021-08-01, 12 km deep.

2021-08-01 00:30 UTC · 12 km deep · released about 21 lb of TNT

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: 2021-08-01 00:30 UTC
Magnitude: M 1.9 (ml)
Depth: 12 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1911 days ago · we first saw it 1911 days ago

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 8 km (5 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
Magna, Utah 2020 M 5.7 500,000× the energy of this one
Around the size people start to feel M 3.0 45× the energy of this one
This earthquake M 1.9 about 21 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 8.2 on 2021-07-29 — about 2,800,000,000 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

8.2 1938 Semidi Islands, Alaska Earthquake · 15 km W of this epicentre Nov 10, 1938
6.9 105 km ESE of Perryville, Alaska · 27 km NNE of this epicentre Nov 17, 1938
6.6 104 km SSE of Perryville, Alaska · 48 km WSW of this epicentre Nov 11, 1938
6.2 143 km SE of Perryville, Alaska · 36 km SSE of this epicentre Mar 25, 1927
6.2 74 km SE of Perryville, Alaska · 35 km NW of this epicentre Aug 6, 1927

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

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

2.7 140 km SE of Perryville, Alaska 15:04 UTC
2.1 127 km SE of Perryville, Alaska 04:52 UTC
2.0 124 km SE of Perryville, Alaska 10:39 UTC
3.0 123 km SE of Perryville, Alaska 07:53 UTC
1.8 76 km SE of Perryville, Alaska 07:44 UTC
2.3 128 km SE of Perryville, Alaska 06:19 UTC
2.5 61 km SE of Perryville, Alaska 23:55 UTC
2.0 62 km SE of Perryville, Alaska 17:01 UTC
2.7 121 km SE of Perryville, Alaska 16:27 UTC
2.1 96 km SSE of Perryville, Alaska 15:33 UTC
2.3 117 km SSE of Perryville, Alaska 13:54 UTC
2.5 140 km SE of Perryville, Alaska 09:51 UTC
3.4 146 km SE of Perryville, Alaska 07:15 UTC
2.3 146 km SE of Perryville, Alaska 04:30 UTC
3.0 149 km SE of Perryville, Alaska 03:54 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 08:38 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.