M4.7 Earthquake 80 km ENE of Tadine, New Caledonia — September 26, 2026

On September 26, 2026 at 01:17 UTC, a magnitude 4.7 shallow crustal earthquake struck 80 km ENE of Tadine, New Caledonia, at a depth of 10.0 km and coordinates -21.2949°, 168.6129°. This earthquake was detected by 18 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — a useful intuition for the size of the slip patch on the fault.

Active aftershock sequence: This earthquake is the mainshock of an ongoing aftershock sequence. In the 28 hours since the mainshock, the USGS has recorded 10 aftershocks within 20 km of the epicenter, including 10 of magnitude 3.0 or greater. The strongest aftershock was a magnitude 5.1 event 2 hours ago. Aftershock sequences from mainshocks of magnitude 4.7 typically continue for several days and gradually diminish over time, though occasional larger aftershocks remain possible.