Reviewed by USGS19y ago
M4.5 earthquake south of the Mariana Islands
Wednesday, October 3, 2007, 18:00:58 UTC · 10.500°N, 145.195°E
A magnitude 4.5 earthquake struck south of the Mariana Islands on Wednesday, October 3, 2007, 18:00:58 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M5.0 on October 2, 2007.
- Magnitude
- 4.5
- Light · mb
- Depth
- 10 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
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
178 km
from the nearest mapped plate boundary, between the Mariana and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
10 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on October 4, 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 263 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.832 km S of Inarajan Village, GuamAugust 8, 1993 · 279 km N of this epicenter
- 7.2265 km S of Merizo Village, GuamJanuary 28, 1931 · 90 km NW of this epicenter
- 7.1261 km S of Merizo Village, GuamMay 9, 1917 · 97 km NW of this epicenter
- 7.120 km SSW of Merizo Village, GuamApril 26, 2002 · 295 km N of this epicenter
- 7.098 km SSE of Inarajan Village, GuamDecember 9, 1909 · 214 km N of this epicenter
- 7.069 km SSE of Inarajan Village, GuamOctober 12, 2001 · 244 km N of this epicenter
- 6.9south of the Mariana IslandsSeptember 30, 2007 · 57 km E of this epicenter
- 6.4279 km S of Merizo Village, GuamMay 6, 1917 · 113 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1993M7.8
Tuman Bay, Apra Harbor
8 Aug 1993 · 279 km away · intensity IX
$250 million damagetsunami
- 1909M8.0
Guam
9 Dec 1909 · 223 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 2001M7.0
Guam
12 Oct 2001 · 244 km away · intensity VIII
Moderate damage ($1–5M)
- 2002M7.1
Guam
26 Apr 2002 · 295 km away · intensity VII
Limited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.