Reviewed by USGS102y ago
M6.3 earthquake southeast of the Loyalty Islands
Wednesday, April 1, 1925, 17:20:05 UTC · 21.687°S, 171.661°E
A magnitude 6.3 earthquake struck southeast of the Loyalty Islands on Wednesday, April 1, 1925, 17:20:05 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on February 9, 1925.
- Magnitude
- 6.3
- Strong · mw
- 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 earthquake
In context
How big was it, and why here?
Energy released
46 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 95 times the energy of a magnitude 5.0.
Tectonic setting
157 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 21 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2southeast of the Loyalty IslandsNovember 14, 1906 · 95 km S of this epicenter
- 7.1southeast of the Loyalty IslandsApril 14, 1906 · 76 km SW of this epicenter
- 7.1175 km SE of Isangel, VanuatuMarch 30, 1910 · 169 km NW of this epicenter
- 7.0204 km E of Tadine, New CaledoniaFebruary 1, 1923 · 187 km W of this epicenter
- 6.893 km S of Isangel, VanuatuJune 1, 1910 · 281 km NW of this epicenter
- 6.8southeast of the Loyalty IslandsFebruary 9, 1925 · 128 km SW of this epicenter
- 6.8southeast of the Loyalty IslandsMarch 10, 1906 · 20 km S 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:
- 1901M7.9
Loyalty Islands
9 Aug 1901 · 175 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.