Reviewed by USGSAlaska10y ago
M2.6 earthquake 131 km ESE of Atka, Alaska
Wednesday, February 24, 2016, 13:19:01 UTC · 51.925°N, 172.340°W
A magnitude 2.6 earthquake struck 131 km ESE of Atka, Alaska on Wednesday, February 24, 2016, 13:19:01 UTC, at a depth of 4.9 km (shallow).
- Magnitude
- 2.6
- Minor · ml
- Depth
- 5 km
- Shallow
- Felt reports
- 0
- Max intensity I
- 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
120 kg of TNT
That is about 1/125,702 of the Hiroshima bomb. A magnitude 5.0 releases about 3,981 times more energy.
Tectonic setting
91 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
5 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M3.7 on February 26, 2016. 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 937 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 · 231 km W of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 174 km W of this epicenter
- 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 210 km SE of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 299 km W of this epicenter
- 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 203 km NE of this epicenter
- 7.3Fox Islands, Aleutian Islands, AlaskaJune 24, 2011 · 37 km E of this epicenter
- 7.158 km WNW of Atka, AlaskaFebruary 28, 1970 · 186 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 · 231 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 174 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 105 km away
Limited damage (under $1M)tsunami
- 1907M7.8
Aleutian Islands
2 Sep 1907 · 192 km away
- 1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 192 km away · intensity V
tsunami
- 1916M7.5
Aleutian Islands: Fox Islands
18 Apr 1916 · 220 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.