Reviewed by USGSAlaska11y ago
M2.5 earthquake 70 km ESE of Adak, Alaska
Monday, June 29, 2015, 07:12:56 UTC · 51.559°N, 175.755°W
A magnitude 2.5 earthquake struck 70 km ESE of Adak, Alaska on Monday, June 29, 2015, 07:12:56 UTC, at a depth of 33.4 km (shallow).
- Magnitude
- 2.5
- Minor · ml
- Depth
- 33 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
85 kg of TNT
That is about 1/177,558 of the Hiroshima bomb. A magnitude 5.0 releases about 5,623 times more energy.
Tectonic setting
90 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
33 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 M4.2 on July 26, 2015. 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 1,105 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 · 11 km SE of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 68 km E of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 130 km W of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 75 km NW of this epicenter
- 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 138 km W of this epicenter
- 7.346 km SSW of Adak, AlaskaJune 10, 1996 · 76 km W of this epicenter
- 7.3Fox Islands, Aleutian Islands, AlaskaJune 24, 2011 · 275 km E of this epicenter
- 7.2207 km WSW of Adak, AlaskaDecember 19, 2007 · 261 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 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 · 11 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 68 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1905M7.9
Andreanof Islands
14 Feb 1905 · 216 km away
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 130 km away · intensity VI
tsunami
- 1996M7.3
Andreanof Islands
10 Jun 1996 · 76 km away
tsunami
- 2011M7.3
Aleutian Islands: Fox Islands
24 Jun 2011 · 275 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.