Reviewed by USGSNorthern Mariana Islands21y ago
M4.2 earthquake in Anatahan region, Northern Mariana Islands
Saturday, March 5, 2005, 20:01:23 UTC · 16.326°N, 145.572°E
A magnitude 4.2 earthquake struck in Anatahan region, Northern Mariana Islands on Saturday, March 5, 2005, 20:01:23 UTC, at a depth of 540.3 km (deep).
- Magnitude
- 4.2
- Light · mb
- Depth
- 540 km
- Deep
- 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
80 km
from the nearest mapped plate boundary, between the Philippine Sea and Mariana plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: deep
540 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 457 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.7Mariana Islands regionDecember 28, 1940 · 290 km NE of this epicenter
- 7.6198 km E of Saipan, Northern Mariana IslandsApril 5, 1990 · 254 km SE of this epicenter
- 7.5Mariana Islands regionJanuary 17, 1940 · 280 km E of this epicenter
- 7.2Pagan region, Northern Mariana IslandsOctober 24, 1930 · 264 km NE of this epicenter
- 7.1233 km NE of Saipan, Northern Mariana IslandsJuly 2, 1949 · 203 km E of this epicenter
- 7.1Pagan region, Northern Mariana IslandsAugust 23, 1995 · 284 km N of this epicenter
- 7.0176 km ESE of San Jose Village, Northern Mariana IslandsMay 18, 1913 · 282 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1902M8.1
Agana
22 Sep 1902 · 192 km away · intensity IX
Severe damage ($5–24M)
- 1997M6.5
Guam
23 Apr 1997 · 270 km away · intensity VII
Limited damage (under $1M)
- 2002M6.5
Saipan
14 Aug 2002 · 256 km away
Limited damage (under $1M)
- 1975M6.1
Guam
1 Nov 1975 · 290 km away · intensity VII
Limited damage (under $1M)
- 1990M7.5
Saipan; Guam
5 Apr 1990 · 254 km away · intensity IV
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.