Huarmey, a coastal town in Peru’s Áncash region, is the nearest named place to a magnitude 5.1 earthquake that struck the Pacific on November 2 at 15:28 UTC. The U.S. Geological Survey put the epicenter 50 km west-southwest of Huarmey and the hypocenter at a depth of 67 km.
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One felt report had reached USGS in the record as read. The record carries no PAGER alert and a tsunami flag of zero, and none of the sources consulted reported damage or injuries.
The Peruvian agency’s version of the same quake
The Instituto Geofisico del Peru reported the event as magnitude 5.0 at 10:28 a.m. local time on Monday, November 2, at a depth of 30 km and 73 km west of Huarmey, at 10.26 degrees south and 78.79 degrees west, according to Radio Nacional del Peru. The institute rated the shaking III to IV in Huarmey, and the outlet said the population felt it mildly. It reported no damage, injuries or casualties.
The two agencies differ on every number: 5.1 against 5.0, 67 km against 30 km deep, and 50 km against 73 km from town. Gaps like that are common for offshore events, where the nearest seismic stations sit on one side of the epicenter, and depth is the hardest value to pin down. Local time of 10:28 a.m. in Peru matches 15:28 UTC, so both agencies are describing the same shock.
What event us7000tuxg says
The USGS event page lists magnitude 5.1, and its catalog entry gives the position as 10.1699 degrees south, 78.5994 degrees west, at a depth of 67.239 km. The magnitude type is mb and the status is reviewed. The last update was posted at 15:51 UTC, about 23 minutes after the origin time, with a felt count of one. The mb scale is a body-wave magnitude commonly used for moderate quakes, and agencies sometimes revise it once a moment magnitude is calculated, so the 5.1 could still change.
A 67 km hypocenter inside the Nazca slab
Peru sits above the Nazca plate, which sinks beneath South America at the Peru-Chile Trench. An IRIS teaching summary written after the magnitude 7.0 Azángaro earthquake of March 1, 2019, puts that convergence at about 58 mm per year and notes that quakes within the plate get deeper from west to east as the slab dips inland. By the usual convention, quakes between about 70 and 300 km deep count as intermediate-depth, which puts a 67 km source just above that line. A source at this depth and this close to the coast sits on the shallow end of that progression, far from the 257 km depth of the Azángaro event. Convergence figures vary by location and source: the Wikipedia summary of the 2021 Mala earthquake gives roughly 78 mm per year for the same plate pair, against 58 mm in the IRIS note, so the rate depends on where along the trench it is measured.
Research on the slab farther inland tells a different story. A 1988 Geophysical Research Letters paper by J. F. Schneider and colleagues, Spatial distribution and B value of intermediate-depth earthquakes beneath central Peru, tracked 67 hypocenters at 100 to 150 km depth and found a nearly horizontal slab segment 450 to 600 km from the trench. Today’s event lies much nearer the trench and shallower than those, so it says little about that flat segment.
Intensity III to IV on the Modified Mercalli scale means weak to light shaking, the kind that rattles windows and is noticed indoors without causing damage. A bigger local case shows the other end. The 2021 Mala earthquake off Lima, at magnitude 6.0 on the Peruvian local scale, reached intensity VI, closed streets with landslides, injured 20 people and killed one. Its depth was listed variously as 32 km by the Peruvian institute and as 45 and 50.6 km elsewhere, the same kind of disagreement seen on Monday.
Huarmey’s recent offshore record
Offshore quakes near Huarmey are not unusual in 2026. On July 11 the Instituto Geofisico del Peru recorded a magnitude 5.2 at 2:58 a.m., at 13 km depth and 170 km southwest of Huarmey, with intensity III in the town, as Caretas reported. The outlet cited the institute’s president, Hernando Tavera, attributing Peru’s frequent quakes to the collision of the Nazca and South American plates. No damage had been reported at publication.
A 2018 Andina report on a magnitude 5.5 quake at 16 km depth off Huarmey shows the usual outcome for such events. Peru’s civil defense institute, Indeci, found no injuries or property damage, described the shaking as moderate in Huarmey and Huaraz, and the Navy’s hydrographic directorate said there was no tsunami threat.
The remaining gap is the Peruvian view of this event. The institute’s own local magnitude, intensity map and distance from Huarmey for the November 2 quake were not retrieved, and its July figures show how its distances and depths can differ from the USGS catalog.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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