4.9

M4.9 Earthquake south of the Fiji IslandsMarch 29, 2023

2023-03-29 07:38:53 UTC (2023-03-29) · approx. 7:38 PM UTC+12 local

MagnitudeM4.9(mb)
Time07:38 UTC7:38 PM UTC+12
Depth621.5 kmdeep-focus
Coordinates-26.262°, 178.518°
Felt byNo felt reports
Status✓ Reviewed by USGS

On March 29, 2023 at 07:38 UTC, a magnitude 4.9 deep-focus earthquake struck south of the Fiji Islands, at a depth of 621.5 km and coordinates -26.2623°, 178.5177°. This earthquake was detected by 51 seismic stations with excellent 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.

The epicenter is located in Fiji, a region characterized by the Fiji Fracture Zone at the junction of the Pacific and Australian plates, with deep-focus seismicity from the subducted slab. View all earthquakes in Fiji.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at -26.26°, 178.52°

Earthquake Details

Magnitude
4.9 mb
Depth
621.5 km
deep-focus
Location
-26.2623°N
178.5177°E

Technical Information

Event ID
us6000k0i7
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Stations Used
51
Azimuthal Gap
75.0°
Min Station Distance
4.329°
RMS Residual
0.98 sec
Last Updated
2023-06-03 22:06:04 UTC

Common Questions

How strong was the magnitude 4.9 earthquake south of the Fiji Islands?

The magnitude 4.9 earthquake that struck south of the Fiji Islands on March 29, 2023 at 07:38 UTC had a depth of 621.5 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -26.2623°, 178.5177°, which is south of the Fiji Islands. View all earthquakes in Fiji.

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: us6000k0i7). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, March 29, 2023). M4.9 Earthquake south of the Fiji IslandsMarch 29, 2023. Retrieved June 3, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000k0i7/