Reviewed by USGSAlaska3mo ago
M4.0 earthquake 46 km S of Sand Point, Alaska
Tuesday, June 23, 2026, 00:34:33 UTC · 54.927°N, 160.382°W
A magnitude 4.0 earthquake struck 46 km S of Sand Point, Alaska on Tuesday, June 23, 2026, 00:34:33 UTC, at a depth of 56.5 km (shallow). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of II (weak).
- Magnitude
- 4.0
- Light · mb
- Depth
- 57 km
- Shallow
- Felt reports
- 1
- Max intensity II
- Est. shaking
- IV
- Light (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
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
131 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
57 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 | 70 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 lists 8 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M2.8 on July 20, 2026. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 2.593 km S of Sand Point, Alaska2mo ago · 48 km S of this epicenter
- 2.832 km SW of Sand Point, Alaska2mo ago · 43 km NW of this epicenter
- 2.659 km SSE of Sand Point, Alaska2mo ago · 14 km S of this epicenter
- 2.594 km SSE of Sand Point, Alaska2mo ago · 49 km SE of this epicenter
- 2.592 km SSE of Sand Point, Alaska2mo ago · 48 km SE of this epicenter
- 2.882 km S of Sand Point, Alaska2mo ago · 38 km S of this epicenter
- 2.594 km S of Sand Point, Alaska3mo ago · 48 km S of this epicenter
- 2.589 km SSE of Sand Point, Alaska3mo ago · 45 km SE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 412 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 · 225 km SW of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 143 km E of this epicenter
- 8.22021 Chignik, Alaska EarthquakeJuly 29, 2021 · 166 km E of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 115 km E of this epicenter
- 7.62020 Sand Point, Alaska EarthquakeOctober 19, 2020 · 60 km SE of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 33 km E of this epicenter
- 7.32025 Sand Point, Alaska EarthquakeJuly 16, 2025 · 41 km S of this epicenter
- 7.22023 Sand Point, Alaska EarthquakeJuly 16, 2023 · 64 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 12 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 · 225 km away · intensity VI
168 deaths$26 million damagetsunami
- 2023M7.2
Alaska Peninsula
16 Jul 2023 · 57 km away · intensity VI
1 deathtsunami
- 2020M7.8
Alaska
22 Jul 2020 · 115 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 · 167 km away · intensity VIII
tsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 40 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.