Reviewed by USGSVanuatu19y ago
M4.0 earthquake 103 km SSE of Isangel, Vanuatu
Thursday, April 12, 2007, 03:32:56 UTC · 20.334°S, 169.806°E
A magnitude 4.0 earthquake struck 103 km SSE of Isangel, Vanuatu on Thursday, April 12, 2007, 03:32:56 UTC, at a depth of 35.0 km (shallow).
- Magnitude
- 4.0
- Light · mb
- Depth
- 35 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
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
135 km
from the nearest mapped plate boundary, between the New Hebrides and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
35 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M5.1 on April 23, 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 1,130 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11920 Vanuatu EarthquakeSeptember 20, 1920 · 144 km W of this epicenter
- 7.828 km ESE of Isangel, VanuatuJune 16, 1910 · 86 km N of this epicenter
- 7.7249 km E of Vao, New CaledoniaMay 16, 1995 · 297 km S of this epicenter
- 7.663 km NW of Isangel, VanuatuOctober 14, 1913 · 167 km NW of this epicenter
- 7.6274 km ESE of Tadine, New CaledoniaMarch 16, 1928 · 233 km S of this epicenter
- 7.5southeast of the Loyalty IslandsJanuary 4, 1998 · 247 km SE of this epicenter
- 7.447 km NW of Isangel, VanuatuOctober 11, 1992 · 151 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 26 recorded deaths. The most severe:
- 1875M8.1
Loyalty Islands: Lifou Island
28 Mar 1875 · 141 km away
26 deathsSevere damage ($5–24M)tsunami
- 1901M7.9
Loyalty Islands
9 Aug 1901 · 186 km away
Moderate damage ($1–5M)tsunami
- 1920M8.1
Loyalty Islands
20 Sep 1920 · 144 km away
Limited damage (under $1M)tsunami
- 1878M7.5
Tanna Island
10 Jan 1878 · 202 km away
Limited damage (under $1M)tsunami
- 1961M7.3
Vanuatu Islands
23 Jul 1961 · 258 km away · intensity VI
Limited damage (under $1M)tsunami
- 1913M8.1
Vanuatu Islands
14 Oct 1913 · 125 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.