Reviewed by USGSAlaska30y ago
M4.5 earthquake 197 km WSW of Adak, Alaska
Friday, July 26, 1996, 18:15:08 UTC · 51.120°N, 179.212°W
A magnitude 4.5 earthquake struck 197 km WSW of Adak, Alaska on Friday, July 26, 1996, 18:15:08 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.1 on July 24, 1996.
- Magnitude
- 4.5
- Light · mb
- 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 earthquake
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
69 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 723 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.71965 Western Aleutian Islands (Hawadax/Rat Islands) EarthquakeFebruary 4, 1965 · 145 km W of this epicenter
- 8.61957 Atka, Alaska EarthquakeMarch 9, 1957 · 253 km E of this epicenter
- 8.31906 Western Aleutian Islands (Hawadax/Rat Islands) EarthquakeAugust 17, 1906 · 198 km NW of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 120 km NE of this epicenter
- 7.6Rat Islands, Aleutian Islands, AlaskaMarch 30, 1965 · 225 km SW of this epicenter
- 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 194 km NE of this epicenter
- 7.4265 km WSW of Adak, AlaskaFebruary 4, 1965 · 90 km NW of this epicenter
- 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 109 km E 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 2 recorded deaths. The most severe:
- 1957M8.6
Alaska
9 Mar 1957 · 253 km away
2 deathsSevere damage ($5–24M)tsunami
- 1965M8.7
Aleutian Islands: Rat Islands
4 Feb 1965 · 145 km away · intensity VI
Under $1 million damagetsunami
- 1906M8.3
Aleutian Islands: Rat Islands
17 Aug 1906 · 198 km away
- 1905M7.9
Andreanof Islands
14 Feb 1905 · 64 km away
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 120 km away · intensity VI
tsunami
- 1965M7.6
Aleutian Islands: Rat Islands
30 Mar 1965 · 220 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.