Reviewed by USGSVanuatu53y ago
M4.8 earthquake 23 km W of Port-Olry, Vanuatu
Monday, January 28, 1974, 01:59:36 UTC · 15.009°S, 166.858°E
A magnitude 4.8 earthquake struck 23 km W of Port-Olry, Vanuatu on Monday, January 28, 1974, 01:59:36 UTC, at a depth of 23.0 km (shallow). It is the strongest earthquake within 300 km since an M5.0 on January 27, 1974.
- Magnitude
- 4.8
- Light · mb
- Depth
- 23 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
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
66 km
from the nearest mapped plate boundary, between the New Hebrides and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
23 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 M5.4 on January 28, 1974. 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 302 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8186 km NNW of Sola, VanuatuDecember 17, 1957 · 289 km N of this epicenter
- 7.745 km NNE of Port-Olry, VanuatuMay 20, 1965 · 54 km NE of this epicenter
- 7.631 km S of Luganville, VanuatuAugust 11, 1965 · 95 km S of this epicenter
- 7.581 km NW of Port-Olry, VanuatuDecember 28, 1973 · 67 km NW of this epicenter
- 7.447 km WSW of Norsup, VanuatuNovember 9, 1910 · 142 km S of this epicenter
- 7.443 km W of Norsup, VanuatuAugust 13, 1965 · 125 km S of this epicenter
- 7.3207 km E of Sola, VanuatuFebruary 19, 1905 · 297 km E of this epicenter
- 7.344 km SSW of Sola, VanuatuJanuary 5, 1915 · 102 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1 recorded deaths. The most severe:
- 1971M7.1
Espiritu Santo, Port Vila
27 Oct 1971 · 66 km away · intensity VII
1 deathSevere damage ($5–24M)
- 1965M7.6
Vanuatu Islands
11 Aug 1965 · 95 km away
Moderate damage ($1–5M)tsunami
- 1973M7.5
Espiritu Santo, Luganille
28 Dec 1973 · 67 km away · intensity VII
Moderate damage ($1–5M)
- 1910M7.2
Espiritu Santo
10 Nov 1910 · 119 km away
Moderate damage ($1–5M)tsunami
- 1973M7.2
Luganville, Lamap
29 Dec 1973 · 13 km away · intensity VIII
Moderate damage ($1–5M)
- 1909
Espiritu Santo
8 Jul 1909 · 66 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.