4.9

M4.9 Earthquake southeast of the Loyalty IslandsSeptember 30, 2023

2023-09-30 06:10:41 UTC (2023-09-30) · approx. 5:10 PM UTC+11 local

MagnitudeM4.9(mb)
Time06:10 UTC5:10 PM UTC+11
Depth86.8 kmintermediate depth
Coordinates-22.501°, 171.651°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 30, 2023 at 06:10 UTC, a magnitude 4.9 intermediate depth earthquake struck southeast of the Loyalty Islands, at a depth of 86.8 km and coordinates -22.5012°, 171.6511°. This earthquake was detected by 31 seismic stations with good location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -22.50°, 171.65°

Earthquake Details

Magnitude
4.9 mb
Depth
86.8 km
intermediate depth
Location
-22.5012°N
171.6511°E

Technical Information

Event ID
us6000lbvg
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Stations Used
31
Azimuthal Gap
125.0°
Min Station Distance
3.888°
RMS Residual
0.79 sec
Last Updated
2023-12-09 22:00:42 UTC

Common Questions

How strong was the magnitude 4.9 earthquake southeast of the Loyalty Islands?

The magnitude 4.9 earthquake that struck southeast of the Loyalty Islands on September 30, 2023 at 06:10 UTC had a depth of 86.8 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -22.5012°, 171.6511°, which is southeast of the Loyalty Islands.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.

Authoritative source: USGS event page (event ID: us6000lbvg). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, September 30, 2023). M4.9 Earthquake southeast of the Loyalty IslandsSeptember 30, 2023. Retrieved December 9, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lbvg/