Reviewed by USGSAlaska6y ago
M2.7 earthquake 103 km SE of Sand Point, Alaska
Saturday, October 10, 2020, 21:04:42 UTC · 54.806°N, 159.165°W
A magnitude 2.7 earthquake struck 103 km SE of Sand Point, Alaska on Saturday, October 10, 2020, 21:04:42 UTC, at a depth of 21.1 km (shallow).
- Magnitude
- 2.7
- Minor · ml
- Depth
- 21 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
169 kg of TNT
That is about 1/88,990 of the Hiroshima bomb. A magnitude 5.0 releases about 2,818 times more energy.
Tectonic setting
97 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
21 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 342 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M7.6 on October 19, 2020. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 2.991 km SSE of Sand Point, Alaska5y ago · 43 km SW of this epicenter
- 3.287 km SSE of Sand Point, Alaska5y ago · 43 km W of this epicenter
- 2.888 km ESE of Sand Point, Alaska5y ago · 16 km NW of this epicenter
- 2.9106 km SSE of Sand Point, Alaska5y ago · 49 km SW of this epicenter
- 2.8111 km SE of Sand Point, Alaska5y ago · 29 km SW of this epicenter
- 2.689 km ESE of Sand Point, Alaska5y ago · 17 km N of this epicenter
- 2.785 km SE of Sand Point, Alaska5y ago · 36 km W of this epicenter
- 3.9108 km SSE of Sand Point, Alaska5y ago · 44 km SW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 280 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 · 280 km SW of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 75 km NE of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 47 km NE of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 51 km NW of this epicenter
- 7.190 km SE of King Cove, AlaskaMay 14, 1948 · 130 km W of this epicenter
- 7.0113 km ESE of Chignik, AlaskaMay 4, 1923 · 190 km NE of this epicenter
- 7.071 km SE of King Cove, AlaskaMay 30, 1991 · 159 km W of this epicenter
- 7.0164 km SE of Chignik, AlaskaSeptember 4, 1989 · 183 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 168 recorded deaths. The most severe:
- 1946M8.6
Unimak Island
1 Apr 1946 · 280 km away · intensity VI
168 deaths$26 million damagetsunami
- 2020M7.8
Alaska
22 Jul 2020 · 47 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 90 km away · intensity VI
tsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 119 km away
tsunami
- 2020M7.6
Alaska
19 Oct 2020 · 37 km away · intensity IX
tsunami
- 1948M7.5
Alaska Peninsula
14 May 1948 · 123 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.