M5.4 earthquake 260 km SE of Perryville, Alaska

Monday, April 25, 2022, 16:31:27 UTC · 54.363°N, 156.075°W

A magnitude 5.4 earthquake struck 260 km SE of Perryville, Alaska on Monday, April 25, 2022, 16:31:27 UTC, at a depth of 12.2 km (shallow). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M5.6 on October 31, 2021.

Tsunami flagUSGS sets this flag for large events in oceanic regions so tsunami warning centers review them. It does not by itself mean a tsunami occurred. Check tsunami.gov and local authorities for official messages.

Magnitude: 5.4; Moderate · mww
Depth: 12 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: I; Not felt (ShakeMap)
PAGER alert: Green; Impact estimate
Tsunami: Flag; Check tsunami.gov

Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

2 kilotons of TNT

That is about 1/8 of the Hiroshima bomb. It released about 4 times the energy of a magnitude 5.0.

Tectonic setting

19 km

from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

12 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

Did You Feel It?

Where it was felt

No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No populated area was estimated to feel noticeable shaking.

After the main event

Aftershocks within 75 km

USGS lists 19 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.4 on April 29, 2022. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 255 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

2020M7.8
Alaska
22 Jul 2020 · 180 km away · intensity VII
Limited damage (under $1M)tsunami
1938M8.2
Alaska
10 Nov 1938 · 192 km away · intensity VI
tsunami
2021M8.2
Alaska Peninsula
29 Jul 2021 · 156 km away · intensity VIII
tsunami
2020M7.6
Alaska
19 Oct 2020 · 231 km away · intensity IX
tsunami
1989M6.9
Alaska
4 Sep 1989 · 140 km away
tsunami
1880
Alaska Peninsula
29 Sep 1880 · 163 km away
tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers