Reviewed by USGSAlaska18y ago
M2.9 earthquake 48 km SSE of Atka, Alaska
Saturday, June 21, 2008, 14:41:44 UTC · 51.785°N, 173.947°W
A magnitude 2.9 earthquake struck 48 km SSE of Atka, Alaska on Saturday, June 21, 2008, 14:41:44 UTC, at a depth of 14.8 km (shallow).
- Magnitude
- 2.9
- 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
338 kg of TNT
That is about 1/44,601 of the Hiroshima bomb. A magnitude 5.0 releases about 1,413 times more energy.
Tectonic setting
96 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 M2.8 on June 29, 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 783 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 · 120 km W of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 64 km SW of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 255 km W of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 190 km W of this epicenter
- 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 288 km NE of this epicenter
- 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 264 km W of this epicenter
- 7.346 km SSW of Adak, AlaskaJune 10, 1996 · 203 km W of this epicenter
- 7.175 km S of Adak, AlaskaMarch 14, 1957 · 204 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 · 120 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 64 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 205 km away
Limited damage (under $1M)tsunami
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 255 km away · intensity VI
tsunami
- 1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 287 km away · intensity V
tsunami
- 1996M7.3
Andreanof Islands
10 Jun 1996 · 203 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.