Reviewed by USGSFiji28y ago
M4.0 earthquake 195 km ESE of Labasa, Fiji
Thursday, July 23, 1998, 03:17:07 UTC · 17.149°S, 178.954°W
A magnitude 4.0 earthquake struck 195 km ESE of Labasa, Fiji on Thursday, July 23, 1998, 03:17:07 UTC, at a depth of 550.0 km (deep).
- Magnitude
- 4.0
- Light · mb
- Depth
- 550 km
- Deep
- 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
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
173 km
from the nearest mapped plate boundary, between the Niuafo'ou and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: deep
550 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on August 18, 1998. 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 717 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8Fiji regionJanuary 1, 1919 · 258 km S of this epicenter
- 7.6178 km E of Levuka, FijiFebruary 22, 1909 · 116 km S of this epicenter
- 7.6144 km SSW of Leava, Wallis and FutunaMay 23, 1956 · 191 km N of this epicenter
- 7.6240 km E of Levuka, FijiMarch 9, 1994 · 114 km SE of this epicenter
- 7.4227 km E of Levuka, FijiAugust 21, 1910 · 86 km SE of this epicenter
- 7.2Fiji regionMarch 31, 1907 · 236 km SE of this epicenter
- 7.2178 km ENE of Levuka, FijiMarch 29, 1998 · 47 km S of this epicenter
- 7.1217 km E of Levuka, FijiJuly 8, 1916 · 104 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 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 · 139 km away · intensity VIII
Moderate damage ($1–5M)
- 1979M6.9
Fiji Islands
16 Nov 1979 · 118 km away
Moderate damage ($1–5M)tsunami
- 1932M6.4
Koro,Mudu,Suvasavu
8 Mar 1932 · 180 km away · intensity VII
Moderate damage ($1–5M)
- 1884
Macuata
Jan 1884 · 253 km away · intensity VII
Limited damage (under $1M)tsunami
- 1909M7.8
Fiji Islands
22 Feb 1909 · 95 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 258 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.