M7.8 earthquake 196 km NW of Sola, Vanuatu

Wednesday, October 7, 2009, 22:18:51 UTC · 12.517°S, 166.382°E

A magnitude 7.8 earthquake struck 196 km NW of Sola, Vanuatu on Wednesday, October 7, 2009, 22:18:51 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.9 on July 17, 1980.

Magnitude: 7.8; Major · mwc
Depth: 35 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VI; Strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

7.6 megatons of TNT

That is about 502 times the Hiroshima bomb. It released about 15,849 times the energy of a magnitude 5.0.

Tectonic setting

58 km

from the nearest mapped plate boundary, between the Pacific and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

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 200 km

USGS lists 238 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M7.4 on October 7, 2009. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,501 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

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. The most severe:

1973M7.5
Espiritu Santo, Luganille
28 Dec 1973 · 217 km away · intensity VII
Moderate damage ($1–5M)
1910M7.2
Espiritu Santo
10 Nov 1910 · 165 km away
Moderate damage ($1–5M)tsunami
1973M7.2
Luganville, Lamap
29 Dec 1973 · 295 km away · intensity VIII
Moderate damage ($1–5M)
2002M5.9
Mere Lava Island
27 Nov 2002 · 269 km away
Moderate damage ($1–5M)
1997M7.7
Santa Cruz Islands; Vanuatu
21 Apr 1997 · 33 km away
Limited damage (under $1M)tsunami
1980M7.5
Santa Cruz Islands: Banks
8 Jul 1980 · 12 km away
Limited damage (under $1M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers