Reviewed by USGS42y ago
M4.1 earthquake in Vanuatu region
Friday, September 7, 1984, 23:48:16 UTC · 18.373°S, 172.242°E
A magnitude 4.1 earthquake struck in Vanuatu region on Friday, September 7, 1984, 23:48:16 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 4.1
- Light · mb
- Depth
- 33 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 earthquake
In context
How big was it, and why here?
Energy released
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
108 km
from the nearest mapped plate boundary, between the Conway Reef and New Hebrides plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
33 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 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 67 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.262 km NE of Isangel, VanuatuJuly 2, 1953 · 286 km W of this epicenter
- 6.986 km NE of Isangel, VanuatuMarch 25, 1912 · 255 km W of this epicenter
- 6.946 km NE of Isangel, VanuatuJune 30, 1905 · 294 km W of this epicenter
- 6.6Fiji regionJuly 3, 1959 · 249 km N of this epicenter
- 6.5286 km E of Port-Vila, VanuatuNovember 3, 1907 · 162 km NW of this epicenter
- 6.5VanuatuJuly 24, 1947 · 257 km W of this epicenter
- 6.5Vanuatu regionJanuary 10, 1948 · 254 km SE of this epicenter
- 6.5Vanuatu regionJuly 3, 1959 · 253 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 1 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1910M7.9
Vanuatu Islands
16 Jun 1910 · 297 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.