Reviewed by USGS37y ago
M4.9 earthquake south of the Fiji Islands
Sunday, March 4, 1990, 19:40:28 UTC · 21.267°S, 175.939°E
A magnitude 4.9 earthquake struck south of the Fiji Islands on Sunday, March 4, 1990, 19:40:28 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.9 on March 4, 1990.
- Magnitude
- 4.9
- 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
338 tons of TNT
That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.
Tectonic setting
2 km
from the nearest mapped plate boundary, between the Australian and Conway Reef plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.1 on March 6, 1990. 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 87 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6south of the Fiji IslandsMarch 3, 1990 · 124 km SW of this epicenter
- 6.8south of the Fiji IslandsNovember 7, 1988 · 144 km SW of this epicenter
- 6.6southeast of the Loyalty IslandsMarch 3, 1990 · 223 km SW of this epicenter
- 6.6southeast of the Loyalty IslandsJuly 23, 1988 · 144 km SW of this epicenter
- 6.6Vanuatu regionNovember 4, 1934 · 156 km SW of this epicenter
- 6.5266 km S of Nadi, FijiMarch 15, 1920 · 171 km NE of this epicenter
- 6.5southeast of the Loyalty IslandsNovember 4, 1934 · 176 km SW of this epicenter
- 6.5Vanuatu regionMarch 10, 1948 · 237 km W 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:
- 1990M7.6
Fiji Islands
3 Mar 1990 · 124 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.