Reviewed by USGSAlaska18y ago
M2.6 earthquake 140 km SW of Adak, Alaska
Monday, September 15, 2008, 06:00:23 UTC · 51.102°N, 178.226°W
A magnitude 2.6 earthquake struck 140 km SW of Adak, Alaska on Monday, September 15, 2008, 06:00:23 UTC, at a depth of 15.0 km (shallow).
- Magnitude
- 2.6
- Minor · ml
- Depth
- 15 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
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
68 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
15 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M3.3 on October 3, 2008. 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 1,045 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.71965 Western Aleutian Islands (Hawadax/Rat Islands) EarthquakeFebruary 4, 1965 · 214 km W of this epicenter
- 8.61957 Atka, Alaska EarthquakeMarch 9, 1957 · 186 km E of this epicenter
- 8.31906 Western Aleutian Islands (Hawadax/Rat Islands) EarthquakeAugust 17, 1906 · 263 km W of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 244 km E of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 66 km NE of this epicenter
- 7.8Rat Islands, Aleutian Islands, AlaskaNovember 17, 2003 · 218 km W of this epicenter
- 7.6Rat Islands, Aleutian Islands, AlaskaMarch 30, 1965 · 289 km W of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 137 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 15 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 · 186 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 244 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1965M8.7
Aleutian Islands: Rat Islands
4 Feb 1965 · 214 km away · intensity VI
Under $1 million damagetsunami
- 1906M8.3
Aleutian Islands: Rat Islands
17 Aug 1906 · 263 km away
- 1905M7.9
Andreanof Islands
14 Feb 1905 · 47 km away
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 66 km away · intensity VI
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.