Reviewed by USGSAlaska3y ago
M2.6 earthquake 51 km S of Sand Point, Alaska
Tuesday, August 15, 2023, 21:25:14 UTC · 54.873°N, 160.397°W
A magnitude 2.6 earthquake struck 51 km S of Sand Point, Alaska on Tuesday, August 15, 2023, 21:25:14 UTC, at a depth of 30.5 km (shallow).
- Magnitude
- 2.6
- Minor · ml
- Depth
- 31 km
- Shallow
- 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
120 kg of TNT
That is about 1/125,702 of the Hiroshima bomb. A magnitude 5.0 releases about 3,981 times more energy.
Tectonic setting
126 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: shallow
31 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 10 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on August 20, 2023. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 3.143 km S of Sand Point, Alaska3y ago · 10 km NW of this epicenter
- 2.684 km SE of Sand Point, Alaska3y ago · 46 km E of this epicenter
- 2.555 km SSE of Sand Point, Alaska3y ago · 5 km SE of this epicenter
- 2.840 km SSW of Sand Point, Alaska3y ago · 24 km NW of this epicenter
- 3.588 km SSE of Sand Point, Alaska3y ago · 41 km SE of this epicenter
- 4.174 km SSW of Sand Point, Alaska3y ago · 45 km W of this epicenter
- 3.577 km SE of Sand Point, Alaska3y ago · 49 km E of this epicenter
- 4.579 km SSW of Sand Point, Alaska3y ago · 49 km W of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 393 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 · 221 km SW of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 145 km E of this epicenter
- 8.22021 Chignik, Alaska EarthquakeJuly 29, 2021 · 169 km E of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 117 km E of this epicenter
- 7.62020 Sand Point, Alaska EarthquakeOctober 19, 2020 · 58 km SE of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 36 km NE of this epicenter
- 7.22023 Sand Point, Alaska EarthquakeJuly 16, 2023 · 58 km SW of this epicenter
- 7.190 km SE of King Cove, AlaskaMay 14, 1948 · 58 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 · 221 km away · intensity VI
168 deaths$26 million damagetsunami
- 2023M7.2
Alaska Peninsula
16 Jul 2023 · 52 km away · intensity VI
1 deathtsunami
- 2020M7.8
Alaska
22 Jul 2020 · 117 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 145 km away · intensity VI
tsunami
- 2021M8.2
Alaska Peninsula
29 Jul 2021 · 170 km away · intensity VIII
tsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 41 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.