Reviewed by USGSAlaska2y ago
M2.5 earthquake 32 km ENE of Sand Point, Alaska
Saturday, February 3, 2024, 23:07:47 UTC · 55.432°N, 160.012°W
A magnitude 2.5 earthquake struck 32 km ENE of Sand Point, Alaska on Saturday, February 3, 2024, 23:07:47 UTC, at a depth of 79.4 km (intermediate).
- Magnitude
- 2.5
- Minor · ml
- Depth
- 79 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
85 kg of TNT
That is about 1/177,558 of the Hiroshima bomb. A magnitude 5.0 releases about 5,623 times more energy.
Tectonic setting
179 km
from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
79 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M2.5 on February 9, 2024. 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 343 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 · 282 km SW of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 119 km E of this epicenter
- 8.22021 Chignik, Alaska EarthquakeJuly 29, 2021 · 134 km E of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 98 km SE of this epicenter
- 7.62020 Sand Point, Alaska EarthquakeOctober 19, 2020 · 95 km S of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 49 km S of this epicenter
- 7.22023 Sand Point, Alaska EarthquakeJuly 16, 2023 · 125 km SW of this epicenter
- 7.190 km SE of King Cove, AlaskaMay 14, 1948 · 119 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 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 · 282 km away · intensity VI
168 deaths$26 million damagetsunami
- 2023M7.2
Alaska Peninsula
16 Jul 2023 · 118 km away · intensity VI
1 deathtsunami
- 2020M7.8
Alaska
22 Jul 2020 · 98 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 104 km away · intensity VI
tsunami
- 2021M8.2
Alaska Peninsula
29 Jul 2021 · 138 km away · intensity VIII
tsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 79 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.