Reviewed by USGSAlaska70y ago
M6.0 earthquake 61 km SSW of Adak, Alaska
Tuesday, March 19, 1957, 11:28:56 UTC · 51.336°N, 176.852°W
A magnitude 6.0 earthquake struck 61 km SSW of Adak, Alaska on Tuesday, March 19, 1957, 11:28:56 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.0 on March 17, 1957.
- Magnitude
- 6.0
- Moderate · mw
- Depth
- 35 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 earthquake
In context
How big was it, and why here?
Energy released
13 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 28 times the energy of a magnitude 5.0.
Tectonic setting
89 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
35 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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 133 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 · 87 km E of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 62 km N of this epicenter
- 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 64 km W of this epicenter
- 7.2238 km WSW of Adak, AlaskaMarch 22, 1905 · 210 km W of this epicenter
- 7.2162 km WSW of Adak, AlaskaMarch 16, 1957 · 140 km W of this epicenter
- 7.175 km S of Adak, AlaskaMarch 14, 1957 · 18 km SE of this epicenter
- 7.160 km SW of Adak, AlaskaMarch 12, 1957 · 32 km NW of this epicenter
- 7.0Rat Islands, Aleutian Islands, AlaskaFebruary 6, 1916 · 294 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 3 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 · 87 km away
2 deathsSevere damage ($5–24M)tsunami
- 1905M7.9
Andreanof Islands
14 Feb 1905 · 137 km away
- 1946
East Aleutian Islands
1 Nov 1946 · 164 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.