Reviewed by USGSFiji104y ago
M6.5 earthquake 98 km NE of Labasa, Fiji
Thursday, July 12, 1923, 03:15:39 UTC · 15.778°S, 179.983°E
A magnitude 6.5 earthquake struck 98 km NE of Labasa, Fiji on Thursday, July 12, 1923, 03:15:39 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.7 on January 1, 1922.
- Magnitude
- 6.5
- Strong · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
91 kilotons of TNT
That is about 6 times the Hiroshima bomb. It released about 191 times the energy of a magnitude 5.0.
Tectonic setting
16 km
from the nearest mapped plate boundary, between the Balmoral Reef and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
15 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 8 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6178 km E of Levuka, FijiFebruary 22, 1909 · 289 km S of this epicenter
- 7.4227 km E of Levuka, FijiAugust 21, 1910 · 275 km SE of this epicenter
- 7.1217 km E of Levuka, FijiJuly 8, 1916 · 291 km SE of this epicenter
- 6.7139 km S of Alo, Wallis and FutunaJanuary 1, 1922 · 183 km E of this epicenter
- 6.584 km S of Alo, Wallis and FutunaMay 31, 1907 · 206 km E of this epicenter
- 6.5102 km ESE of Labasa, FijiOctober 3, 1919 · 121 km S of this epicenter
- 6.4225 km S of Alo, Wallis and FutunaJune 4, 1918 · 172 km E of this epicenter
- 6.3292 km S of Alo, Wallis and FutunaMay 8, 1919 · 284 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1919M6.9
Rabi,Tunuloa Mission,Suvasavu
3 Oct 1919 · 69 km away · intensity VIII
Moderate damage ($1–5M)
- 1884
Macuata
Jan 1884 · 108 km away · intensity VII
Limited damage (under $1M)tsunami
- 1909M7.8
Fiji Islands
22 Feb 1909 · 270 km away
- 1881
Fiji Islands
12 Jul 1881 · 108 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.