Alaska Peninsula

Yes. A magnitude 4.5 earthquake was recorded in the Alaska Peninsula at 20:59 UTC on 2017-03-28, 46 km deep. 1 person has reported feeling it to USGS.

2017-03-28 20:59 UTC · 46 km deep · released about 85 tons of TNT

Felt it? Tell USGS Check my area

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: 2017-03-28 20:59 UTC
Magnitude: M 4.5 (mw)
Depth: 46 km below the surface
Felt: 1 report · strongest reported intensity I
Measured shaking: intensity III (ShakeMap)
USGS impact alert: green
Status: Reviewed by a seismologist

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

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 132 km (82 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 85 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.

Northridge, California 1994 M 6.7 2,000× the energy of this one
Mineral, Virginia 2011 M 5.8 89× the energy of this one
Magna, Utah 2020 M 5.7 63× the energy of this one
This earthquake M 4.5 about 85 tons of TNT
Around the size people start to feel M 3.0 this one released 180× 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 in our catalogue was M 4.5 on 2016-02-14.

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

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

2.5 120 km SSE of Ugashik, Alaska 16:08 UTC
2.1 116 km E of Chignik, Alaska 14:38 UTC
2.0 135 km E of Chignik, Alaska 04:14 UTC
1.9 123 km SSE of Ugashik, Alaska 12:26 UTC
2.3 120 km ENE of Chignik, Alaska 00:14 UTC
2.3 120 km ESE of Chignik, Alaska 07:13 UTC
2.1 111 km SSE of Ugashik, Alaska 12:39 UTC
2.5 129 km ESE of Chignik, Alaska 09:56 UTC
2.6 120 km SSE of Ugashik, Alaska 23:00 UTC
2.5 107 km E of Chignik, Alaska 19:46 UTC
2.5 114 km SSE of Ugashik, Alaska 16:09 UTC
2.1 120 km SE of Ugashik, Alaska 20:06 UTC
2.1 132 km ESE of Chignik, Alaska 17:58 UTC
2.0 119 km SE of Ugashik, Alaska 21:20 UTC
2.0 122 km WSW of Akhiok, Alaska 11:39 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 21:51 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.