M4.9 Earthquake 9 km N of Delta, B.C., MX — November 3, 2026

On November 3, 2026 at 18:27 UTC, a magnitude 4.9 shallow crustal earthquake struck 9 km N of Delta, B.C., MX, at a depth of 15.6 km and coordinates 32.4308°, -115.1797°. The earthquake was reported felt by 291 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 5.0 (moderate). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 57 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 525, placing it among routine seismic activity. The nearest populated place is Ejido Michoacan de Ocampo (population 3,086).

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 323 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.

Active aftershock sequence: This earthquake is the mainshock of an ongoing aftershock sequence. In the 3 hours since the mainshock, the USGS has recorded 8 aftershocks within 20 km of the epicenter, including 0 of magnitude 3.0 or greater. The strongest aftershock was a magnitude 3.0 event 1 hour ago. Aftershock sequences from mainshocks of magnitude 4.9 typically continue for several days and gradually diminish over time, though occasional larger aftershocks remain possible.