M6.6 Earthquake south of the Fiji Islands — July 29, 2025
2025-07-29 17:53:40 UTC (2025-07-29) · approx. 5:53 AM UTC+12 local
On July 29, 2025 at 17:53 UTC, a magnitude 6.6 deep-focus earthquake struck south of the Fiji Islands, at a depth of 553.0 km and coordinates -23.4497°, 178.8580°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 156 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 670, making it a moderate-impact event.
Physical scale: An earthquake of magnitude 6.6 releases seismic energy equivalent to roughly 120 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 22 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
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.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
178.8580°E
Technical Information
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Common Questions
How strong was the magnitude 6.6 earthquake south of the Fiji Islands?
The magnitude 6.6 earthquake that struck south of the Fiji Islands on July 29, 2025 at 17:53 UTC had a depth of 553.0 km. For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at -23.4497°, 178.8580°, 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 6.6 earthquakes can continue for weeks to months and gradually diminish over time.
Actions
Location
Authoritative source: USGS event page (event ID: us6000qw1a). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, July 29, 2025). M6.6 Earthquake south of the Fiji Islands — July 29, 2025. Retrieved October 11, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000qw1a/