Reviewed by USGSAlaska70y ago
M6.4 earthquake 118 km E of Nikolski, Alaska
Friday, March 15, 1957, 02:52:14 UTC · 52.762°N, 167.129°W
A magnitude 6.4 earthquake struck 118 km E of Nikolski, Alaska on Friday, March 15, 1957, 02:52:14 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on March 11, 1957.
- Magnitude
- 6.4
- Strong · mw
- Depth
- 25 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: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
62 kilotons of TNT
That is about 4 times the Hiroshima bomb. It released about 130 times the energy of a magnitude 5.0.
Tectonic setting
59 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
25 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 100 km
USGS lists 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.8 on March 29, 1957. 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 86 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.6The 1946 Unimak Island, Alaska EarthquakeApril 1, 1946 · 298 km E of this epicenter
- 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 276 km SW of this epicenter
- 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 248 km W of this epicenter
- 7.135 km SW of Nikolski, AlaskaMarch 11, 1957 · 139 km W of this epicenter
- 7.0203 km SSE of Unalaska, AlaskaAugust 22, 1940 · 129 km SE of this epicenter
- 6.980 km SW of Nikolski, AlaskaMarch 9, 1957 · 170 km W of this epicenter
- 6.977 km SSW of Nikolski, AlaskaJanuary 23, 1935 · 162 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 168 recorded deaths. The most severe:
- 1946M8.6
Unimak Island
1 Apr 1946 · 298 km away · intensity VI
168 deaths$26 million damagetsunami
- 1917M7.9
Alaska Peninsula
31 May 1917 · 261 km away · intensity V
- 1902M7.8
Aleutian Islands: Fox Islands
1 Jan 1902 · 47 km away
- 1907M7.8
Aleutian Islands
2 Sep 1907 · 176 km away
- 1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 278 km away · intensity V
tsunami
- 1916M7.5
Aleutian Islands: Fox Islands
18 Apr 1916 · 201 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.