Reviewed by USGS37y ago
M5.1 earthquake southeast of the Loyalty Islands
Tuesday, April 3, 1990, 20:04:37 UTC · 22.243°S, 174.265°E
A magnitude 5.1 earthquake struck southeast of the Loyalty Islands on Tuesday, April 3, 1990, 20:04:37 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.4 on March 28, 1990.
- Magnitude
- 5.1
- Moderate · mw
- 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 earthquake
In context
How big was it, and why here?
Energy released
674 tons of TNT
That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.
Tectonic setting
10 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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 144 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 · 93 km E of this epicenter
- 7.2southeast of the Loyalty IslandsNovember 14, 1906 · 275 km W of this epicenter
- 7.1southeast of the Loyalty IslandsAugust 17, 1935 · 288 km W of this epicenter
- 7.0southeast of the Loyalty IslandsAugust 25, 1926 · 230 km SW of this epicenter
- 7.0southeast of the Loyalty IslandsOctober 5, 1944 · 257 km W of this epicenter
- 7.0southeast of the Loyalty IslandsJuly 6, 1981 · 260 km W of this epicenter
- 6.8south of the Fiji IslandsNovember 7, 1988 · 78 km E of this epicenter
- 6.8southeast of the Loyalty IslandsMarch 10, 1906 · 269 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 2 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1990M7.6
Fiji Islands
3 Mar 1990 · 93 km away
- 1944M7.5
Loyalty Islands
5 Oct 1944 · 235 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.