Reviewed by USGSAlaska14y ago
M4.5 earthquake 189 km E of Atka, Alaska
Friday, June 29, 2012, 18:07:13 UTC · 52.171°N, 171.432°W
A magnitude 4.5 earthquake struck 189 km E of Atka, Alaska on Friday, June 29, 2012, 18:07:13 UTC, at a depth of 25.6 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on June 18, 2012.
- Magnitude
- 4.5
- Light · mb
- Depth
- 26 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 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
102 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: shallow
26 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 M2.9 on July 16, 2012. 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 763 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 · 298 km W of this epicenter
- 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 241 km W of this epicenter
- 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 181 km SE of this epicenter
- 7.881 km E of Nikolski, AlaskaJuly 2, 1965 · 272 km E of this epicenter
- 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 150 km N of this epicenter
- 7.3Fox Islands, Aleutian Islands, AlaskaJune 24, 2011 · 31 km SW of this epicenter
- 7.158 km WNW of Atka, AlaskaFebruary 28, 1970 · 239 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 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 · 298 km away
2 deathsSevere damage ($5–24M)tsunami
- 1986M8.0
Aleutian Islands: Adak
7 May 1986 · 241 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 85 km away
Limited damage (under $1M)tsunami
- 1965M6.5
Aleutian Islands: Fox Islands
2 Jul 1965 · 279 km away
Limited damage (under $1M)tsunami
- 1902M7.8
Aleutian Islands: Fox Islands
1 Jan 1902 · 269 km away
- 1907M7.8
Aleutian Islands
2 Sep 1907 · 125 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.