Reviewed by USGSAlaska14y ago
M3.0 earthquake 99 km ESE of Atka, Alaska
Friday, February 3, 2012, 08:05:10 UTC · 51.992°N, 172.783°W
A magnitude 3.0 earthquake struck 99 km ESE of Atka, Alaska on Friday, February 3, 2012, 08:05:10 UTC, at a depth of 73.1 km (intermediate).
- Magnitude
- 3.0
- Minor · ml
- Depth
- 73 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 earthquake
In context
How big was it, and why here?
Energy released
477 kg of TNT
That is about 1/31,575 of the Hiroshima bomb. A magnitude 5.0 releases about 1,000 times more energy.
Tectonic setting
104 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
73 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 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 865 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.61957 Atka, Alaska EarthquakeMarch 9, 1957 · 203 km W of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 147 km W of this epicenter
- 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 240 km SE of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 269 km W of this epicenter
- 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 215 km NE of this epicenter
- 7.346 km SSW of Adak, AlaskaJune 10, 1996 · 286 km W of this epicenter
- 7.3Fox Islands, Aleutian Islands, AlaskaJune 24, 2011 · 65 km E of this epicenter
- 7.175 km S of Adak, AlaskaMarch 14, 1957 · 287 km W 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 2 recorded deaths. The most severe:
- 1957M8.6
Alaska
9 Mar 1957 · 203 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 147 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 136 km away
Limited damage (under $1M)tsunami
- 1907M7.8
Aleutian Islands
2 Sep 1907 · 218 km away
- 1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 222 km away · intensity V
tsunami
- 1916M7.5
Aleutian Islands: Fox Islands
18 Apr 1916 · 237 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.