Reviewed by USGSAlaska23y ago
M3.4 earthquake in Rat Islands, Aleutian Islands, Alaska
Thursday, December 18, 2003, 21:52:42 UTC · 50.120°N, 179.096°E
A magnitude 3.4 earthquake struck in Rat Islands, Aleutian Islands, Alaska on Thursday, December 18, 2003, 21:52:42 UTC, at a depth of 8.0 km (shallow).
- Magnitude
- 3.4
- Minor · ml
- Depth
- 8 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
2 tons of TNT
That is about 1/7,931 of the Hiroshima bomb. A magnitude 5.0 releases about 251 times more energy.
Tectonic setting
49 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
8 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 16 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.7 on December 19, 2003. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 3.1Rat Islands, Aleutian Islands, Alaska23y ago · 44 km W of this epicenter
- 3.2Rat Islands, Aleutian Islands, Alaska23y ago · 37 km W of this epicenter
- 3.6Rat Islands, Aleutian Islands, Alaska23y ago · 33 km NW of this epicenter
- 3.4Rat Islands, Aleutian Islands, Alaska23y ago · 26 km NW of this epicenter
- 3.9Rat Islands, Aleutian Islands, Alaska23y ago · 45 km E of this epicenter
- 3.2Rat Islands, Aleutian Islands, Alaska23y ago · 41 km E of this epicenter
- 4.5south of the Aleutian Islands23y ago · 41 km SE of this epicenter
- 3.3south of the Aleutian Islands23y ago · 35 km SE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 648 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 · 129 km N of this epicenter
- 8.31906 Western Aleutian Islands (Hawadax/Rat Islands) EarthquakeAugust 17, 1906 · 203 km N of this epicenter
- 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 280 km NE of this epicenter
- 7.8Rat Islands, Aleutian Islands, AlaskaNovember 17, 2003 · 118 km N of this epicenter
- 7.6Rat Islands, Aleutian Islands, AlaskaMarch 30, 1965 · 89 km W of this epicenter
- 7.4265 km WSW of Adak, AlaskaFebruary 4, 1965 · 150 km N of this epicenter
- 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 268 km NE of this epicenter
- 7.2238 km WSW of Adak, AlaskaMarch 22, 1905 · 136 km NE 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. The most severe:
- 1965M8.7
Aleutian Islands: Rat Islands
4 Feb 1965 · 129 km away · intensity VI
Under $1 million damagetsunami
- 1906M8.3
Aleutian Islands: Rat Islands
17 Aug 1906 · 203 km away
- 1905M7.9
Andreanof Islands
14 Feb 1905 · 180 km away
- 1996M7.9
Andreanof Islands
10 Jun 1996 · 280 km away · intensity VI
tsunami
- 2003M7.8
Aleutian Islands: Rat Islands
17 Nov 2003 · 118 km away
tsunami
- 1916M7.7
Aleutian Islands
6 Feb 1916 · 185 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.