67 km E of Chignik, Alaska

Yes. A magnitude 1.8 earthquake was recorded 67 km E of Chignik, Alaska at 08:18 UTC on 2023-03-20, 13 km deep.

2023-03-20 08:18 UTC · 13 km deep · released about 15 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: 2023-03-20 08:18 UTC
Magnitude: M 1.8 (ml)
Depth: 13 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1326 days ago · we first saw it 1326 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 3 km (2 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 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 4.0 on 2016-12-16 — about 2,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

6.5 60 km ENE of Chignik, Alaska · 21 km NNW of this epicentre Sep 28, 1941
6.4 61 km ENE of Chignik, Alaska · 30 km NNW of this epicentre Jan 1, 1963
6.4 77 km ESE of Chignik, Alaska · 24 km SSE of this epicentre Mar 24, 1972
6.4 104 km SSE of Ugashik, Alaska · 50 km NE of this epicentre May 20, 1979
6.3 112 km E of Chignik, Alaska · 47 km ESE of this epicentre Feb 25, 1953

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.

2.1 103 km ESE of Chignik, Alaska 01:51 UTC
2.3 92 km E of Chignik, Alaska 05:25 UTC
2.3 87 km S of Ugashik, Alaska 02:40 UTC
3.3 Alaska Peninsula 09:34 UTC
2.1 Alaska Peninsula 13:41 UTC
1.7 56 km ESE of Chignik, Alaska 18:34 UTC
2.1 46 km SE of Chignik, Alaska 05:22 UTC
2.0 67 km E of Chignik, Alaska 08:02 UTC
2.2 101 km E of Chignik, Alaska 00:08 UTC
2.1 101 km ENE of Chignik, Alaska 13:21 UTC
2.3 76 km E of Chignik, Alaska 10:22 UTC
2.4 Alaska Peninsula 06:33 UTC
1.9 54 km ESE of Chignik, Alaska 15:45 UTC
1.6 Alaska Peninsula 18:22 UTC
1.7 54 km E of Chignik, Alaska 05:14 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 22:20 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.