Reviewed by USGS19y ago
M4.4 earthquake in Mariana Islands region
Saturday, September 29, 2007, 13:09:15 UTC · 21.905°N, 142.934°E
A magnitude 4.4 earthquake struck in Mariana Islands region on Saturday, September 29, 2007, 13:09:15 UTC, at a depth of 279.4 km (intermediate).
- Magnitude
- 4.4
- Light · mb
- Depth
- 279 km
- Intermediate
- 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
60 tons of TNT
That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.
Tectonic setting
20 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: intermediate
279 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on October 6, 2007. 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 259 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.9Volcano Islands, Japan regionNovember 24, 1914 · 58 km NW of this epicenter
- 7.6Volcano Islands, Japan regionMarch 28, 2000 · 95 km NE of this epicenter
- 7.5Volcano Islands, Japan regionFebruary 24, 1934 · 173 km NE of this epicenter
- 7.5Volcano Islands, Japan regionSeptember 28, 2007 · 30 km NW of this epicenter
- 7.2Mariana Islands regionJuly 11, 1905 · 106 km E of this epicenter
- 7.2Volcano Islands, Japan regionAugust 27, 1954 · 232 km N of this epicenter
- 7.2Mariana Islands regionJune 19, 1947 · 264 km E of this epicenter
- 7.2Volcano Islands, Japan regionMay 30, 1955 · 274 km N 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. The most severe:
- 1914M8.1
Volcano Islands
24 Nov 1914 · 13 km away
- 2000M7.6
Volcano Islands
28 Mar 2000 · 95 km away
- 2007M7.5
Volcano Islands
28 Sep 2007 · 30 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.