Reviewed by USGSAlaska1mo ago
M3.7 earthquake 7 km SW of Sand Point, Alaska
Thursday, August 20, 2026, 14:46:39 UTC · 55.291°N, 160.599°W
A magnitude 3.7 earthquake struck 7 km SW of Sand Point, Alaska on Thursday, August 20, 2026, 14:46:39 UTC, at a depth of 10.0 km (shallow). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of II (weak).
- Magnitude
- 3.7
- Minor · ml
- Depth
- 10 km
- Shallow
- Felt reports
- 1
- Max intensity II
- Est. shaking
- III
- Weak (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
5 tons of TNT
That is about 1/2,814 of the Hiroshima bomb. A magnitude 5.0 releases about 89 times more energy.
Tectonic setting
173 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
10 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
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| 99661<br>0.330 | II · Weak | 1 | 10 km |
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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 405 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 · 247 km SW of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 154 km E of this epicenter
- 8.22021 Chignik, Alaska EarthquakeJuly 29, 2021 · 172 km E of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 129 km E of this epicenter
- 7.62020 Sand Point, Alaska EarthquakeOctober 19, 2020 · 99 km SE of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 56 km SE of this epicenter
- 7.32025 Sand Point, Alaska EarthquakeJuly 16, 2025 · 81 km S of this epicenter
- 7.22023 Sand Point, Alaska EarthquakeJuly 16, 2023 · 100 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 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 · 247 km away · intensity VI
168 deaths$26 million damagetsunami
- 2023M7.2
Alaska Peninsula
16 Jul 2023 · 93 km away · intensity VI
1 deathtsunami
- 2020M7.8
Alaska
22 Jul 2020 · 129 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 142 km away · intensity VI
tsunami
- 2021M8.2
Alaska Peninsula
29 Jul 2021 · 175 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.