Reviewed by USGSAlaska14y ago
M3.0 earthquake 107 km ESE of Atka, Alaska
Saturday, April 28, 2012, 11:27:30 UTC · 51.851°N, 172.739°W
A magnitude 3.0 earthquake struck 107 km ESE of Atka, Alaska on Saturday, April 28, 2012, 11:27:30 UTC, at a depth of 36.5 km (shallow).
- Magnitude
- 3.0
- Minor · ml
- Depth
- 37 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
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
88 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
37 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M2.5 on April 28, 2012. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 862 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 · 145 km W of this epicenter
- 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 230 km SE of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 272 km W of this epicenter
- 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 225 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 · 66 km E of this epicenter
- 7.175 km S of Adak, AlaskaMarch 14, 1957 · 286 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 · 145 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 127 km away
Limited damage (under $1M)tsunami
- 1907M7.8
Aleutian Islands
2 Sep 1907 · 221 km away
- 1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 212 km away · intensity V
tsunami
- 1916M7.5
Aleutian Islands: Fox Islands
18 Apr 1916 · 245 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.