Reviewed by USGSAlaska6mo ago
M3.9 earthquake 147 km SSE of False Pass, Alaska
Monday, March 30, 2026, 05:06:15 UTC · 53.570°N, 162.868°W
A magnitude 3.9 earthquake struck 147 km SSE of False Pass, Alaska on Monday, March 30, 2026, 05:06:15 UTC, at a depth of 23.7 km (shallow).
- Magnitude
- 3.9
- Minor · mb
- Depth
- 24 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- II
- Weak (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 50 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
11 tons of TNT
That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.
Tectonic setting
32 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
24 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 PAGER estimate is available for this event.
After the main event
Aftershocks within 50 km
USGS lists 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M2.7 on April 5, 2026. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 462 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.6The 1946 Unimak Island, Alaska EarthquakeApril 1, 1946 · 9 km S of this epicenter
- 7.62020 Sand Point, Alaska EarthquakeOctober 19, 2020 · 241 km NE of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 250 km NE of this epicenter
- 7.32025 Sand Point, Alaska EarthquakeJuly 16, 2025 · 192 km NE of this epicenter
- 7.22023 Sand Point, Alaska EarthquakeJuly 16, 2023 · 165 km NE of this epicenter
- 7.190 km SE of King Cove, AlaskaMay 14, 1948 · 159 km NE of this epicenter
- 7.139 km S of Akutan, AlaskaMarch 22, 1957 · 193 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 169 recorded deaths. The most severe:
- 1946M8.6
Unimak Island
1 Apr 1946 · 9 km away · intensity VI
168 deaths$26 million damagetsunami
- 2023M7.2
Alaska Peninsula
16 Jul 2023 · 170 km away · intensity VI
1 deathtsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 200 km away
tsunami
- 2020M7.6
Alaska
19 Oct 2020 · 241 km away · intensity IX
tsunami
- 1948M7.5
Alaska Peninsula
14 May 1948 · 160 km away
- 1957M7.5
Aleutian Islands: Fox Islands
22 Mar 1957 · 220 km away · intensity V
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.