Reviewed by USGSAlaska11y ago
M2.7 earthquake 178 km W of Adak, Alaska
Friday, October 9, 2015, 16:56:51 UTC · 51.812°N, 179.226°W
A magnitude 2.7 earthquake struck 178 km W of Adak, Alaska on Friday, October 9, 2015, 16:56:51 UTC, at a depth of 84.0 km (intermediate).
- Magnitude
- 2.7
- Minor · ml
- Depth
- 84 km
- Intermediate
- Felt reports
- 0
- Max intensity I
- 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
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
145 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
84 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 1,105 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 · 155 km SW of this epicenter
- 8.61957 Atka, Alaska EarthquakeMarch 9, 1957 · 251 km E of this epicenter
- 8.31906 Western Aleutian Islands (Hawadax/Rat Islands) EarthquakeAugust 17, 1906 · 178 km W of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 113 km E of this epicenter
- 7.9Rat Islands, Aleutian Islands, AlaskaJune 23, 2014 · 140 km W of this epicenter
- 7.8Rat Islands, Aleutian Islands, AlaskaNovember 17, 2003 · 165 km SW of this epicenter
- 7.6Rat Islands, Aleutian Islands, AlaskaMarch 30, 1965 · 264 km SW of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 174 km E 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 · 251 km away
2 deathsSevere damage ($5–24M)tsunami
- 1965M8.7
Aleutian Islands: Rat Islands
4 Feb 1965 · 155 km away · intensity VI
Under $1 million damagetsunami
- 1906M8.3
Aleutian Islands: Rat Islands
17 Aug 1906 · 178 km away
- 1905M7.9
Andreanof Islands
14 Feb 1905 · 129 km away
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 113 km away · intensity VI
tsunami
- 2014M7.9
Aleutian Islands
23 Jun 2014 · 140 km away · intensity VI
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.