Reviewed by USGSAlaska18y ago
M2.7 earthquake 151 km SSE of Atka, Alaska
Monday, August 4, 2008, 07:16:49 UTC · 50.874°N, 173.685°W
A magnitude 2.7 earthquake struck 151 km SSE of Atka, Alaska on Monday, August 4, 2008, 07:16:49 UTC, at a depth of 3.7 km (shallow).
- Magnitude
- 2.7
- Minor · ml
- Depth
- 4 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
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
6 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
4 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 M3.0 on August 21, 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 711 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 · 152 km NW of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 105 km NW of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 285 km W of this epicenter
- 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 273 km E of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 238 km NW of this epicenter
- 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 291 km W of this epicenter
- 7.346 km SSW of Adak, AlaskaJune 10, 1996 · 230 km W of this epicenter
- 7.175 km S of Adak, AlaskaMarch 14, 1957 · 216 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 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 · 152 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 105 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 197 km away
Limited damage (under $1M)tsunami
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 285 km away · intensity VI
tsunami
- 1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 259 km away · intensity V
tsunami
- 1996M7.3
Andreanof Islands
10 Jun 1996 · 230 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.