5.5

M5.5 Earthquake 126 km N of Ba, Fiji — March 11, 2023

2023-03-11 13:29:45 UTC (2023-03-11) · approx. 1:29 AM UTC+12 local

Maximum shaking intensity MMI 4.6 (moderate).

MagnitudeM5.5(mww)
Time13:29 UTC≈ 1:29 AM UTC+12
Depth10.0 kmshallow crustal
Coordinates-16.399°, 177.506°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On March 11, 2023 at 13:29 UTC, a magnitude 5.5 shallow crustal earthquake struck 126 km N of Ba, Fiji, at a depth of 10.0 km and coordinates -16.3993°, 177.5056°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 58 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 465, placing it among routine seismic activity. The nearest populated place is Levuka (population 8,360).

Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 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

Nearest Populated Places

Levukapop. 8,360
MMI 2.3 (weak)
Bapop. 14,596
MMI 3.2 (light)
Nadipop. 42,284
MMI 3.3 (light)
Lautokapop. 52,500
MMI 3.2 (light)
Suvapop. 77,366
MMI 2.7 (weak)
Map showing earthquake epicenter at -16.40°, 177.51°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M5.5 earthquake near 126 km N of Ba, Fiji

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak814,159
MMI 4light5,533

Earthquake Details

Magnitude
5.5 mww
Depth
10.0 km
shallow crustal
Location
-16.3993°N
177.5056°E
Intensity (MMI)
4.6
moderate

Technical Information

Event ID
us7000jj4s
Event Type
earthquake
Status
✓ Reviewed
Significance
465
Stations Used
58
Azimuthal Gap
61.0°
Min Station Distance
4.703°
RMS Residual
0.59 sec
Last Updated
2023-05-15 02:49:11 UTC

Common Questions

How strong was the magnitude 5.5 earthquake near Ba, Fiji?

The magnitude 5.5 earthquake that struck 126 km N of Ba, Fiji on March 11, 2023 at 13:29 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at -16.3993°, 177.5056°, which is 126 km N of Ba, Fiji. The nearest populated place is Levuka (population 8,360). View all earthquakes in Fiji.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks and gradually diminish over time.

Actions

View on USGSDid You Feel It?

Location

Fiji
View all Fiji earthquakes

Authoritative source: USGS event page (event ID: us7000jj4s). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, March 11, 2023). M5.5 Earthquake 126 km N of Ba, Fiji — March 11, 2023. Retrieved May 15, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000jj4s/