AYACUCHO, Peru — A magnitude 6.7 earthquake shook the southern Peruvian Andes on Thursday afternoon, and while the country's Civil Defense chief initially told local radio that "no damage of any kind has been reported so far," the Washington Post is reporting at least two people injured and cracks running through homes, schools and health posts. Real damage but nothing close to the ruin that has now hit South America three separate times in under two months.
A Third Quake, By Far the Gentlest
U.S. Geological Survey data placed the quake's center about 38 kilometers northwest of the small town of Upahuacho, in Ayacucho's Parinacochas province, striking just after 1 p.m. local time at a depth of roughly 66 kilometers. Peru's own Instituto Geofísico del Perú measured it larger, at magnitude 7.2, with an epicenter closer to Coracora and a depth near 108 kilometers. The U.S. Embassy in Lima reported at least 6,000 households losing power, and Peru's Navy ruled out any tsunami risk.
Thursday's tremor is the third major earthquake to rattle South America since late June — and the least destructive by a wide margin. On June 24, a rare seismic doublet — magnitude 7.2 followed roughly 39 seconds later by magnitude 7.5 — tore through north-central Venezuela, collapsing buildings across Caracas and flattening large sections of La Guaira. Venezuela's National Assembly president, Jorge Rodríguez, put the confirmed death toll at 6,438 as of Aug. 17, a number that has climbed for nearly two months and could still rise further.
Then on Aug. 10, a magnitude 7.4 earthquake struck Colombia's western Chocó department near San José del Palmar, tearing through Cali, Pereira and Manizales. Colombia's disaster-risk agency, UNGRD, has updated the toll as recently as Aug. 20 to 319 dead, 4,506 injured and 260 still missing, with 364 people rescued and damage reported across 476 municipalities in 15 of the country's 32 departments. Colombia's own Geological Service has called it one of the country's most powerful earthquakes in decades.
Same Ring of Fire, Two Very Different Kinds of Earthquake
Geologists point to two variables to explain why Peru's shaking stayed mild while Venezuela's and Colombia's turned deadly: how far below the surface an earthquake begins, and how much energy it releases once it gets there. All three sit somewhere along the Pacific Ring of Fire, but geologically they are not close cousins.
Venezuela's twin quakes began only around 19 kilometers underground, inside a fracture system where the Caribbean and South American plates scrape past one another along the country's northern coast. Pressure along those faults can build for a century before releasing all at once close to the surface — which is exactly where shaking does the most damage, geologist Reynaldo Charrier of Chile's Andrés Bello University explained.
Colombia's Aug. 10 quake and Thursday's event in Peru, by contrast, both began far deeper — inside the Nazca plate as it bends and slides beneath the continent. USGS put Colombia's depth at roughly 107 kilometers, squarely in what seismologists call an intermediate-depth event; other Colombian government bulletins have placed it anywhere from 96 to 110 kilometers depending on the report. Independent seismologist Amilcar Carrera-Cevallos told Scientific American that at that depth, "the shaking traveled so far but hit more moderately," though Colombia's stronger 7.4 magnitude, combined with soft, sediment-heavy ground around Cali and Pereira that amplifies shaking, still added up to hundreds of deaths.
Thursday's Peru quake shared that same deep, intraplate origin, but its overall energy release came in lower than Colombia's, and it struck a comparatively sparse stretch of the Andes rather than a dense valley city — a likely explanation for why it left cracked walls rather than collapsed ones.
Watched Closely From South Florida
The run of disasters has registered well beyond South America's borders. Large Venezuelan and Colombian communities across South Florida — concentrated in Doral, Miami and Weston — have spent weeks tracking recovery efforts and, in many cases, sending remittances toward rebuilding in La Guaira, Caracas, Cali and Pereira. Peruvian communities elsewhere in the U.S. described a similar instinct Thursday, reaching out to relatives back home even after officials said the damage looked limited.
An Overdue Mega-Quake Still Looms
The cluster of tremors has revived warnings about a far larger earthquake scientists believe is overdue off Peru's central coast. Seismologist César Jiménez Tintaya of Peru's National University of San Marcos said that only about 20% of the energy that has built up along that stretch of coast since a devastating 1746 megathrust earthquake has actually been released — meaning roughly four-fifths of it is still stored underground. That, he said, is why a magnitude of "8.5 to 8.8" remains possible in central Peru. Fabiola Barrenechea of Peru's Intergeographic Foundation named southern Peru itself, alongside northern Chile, Ecuador and southern Colombia, as the areas of greatest concern — while cautioning that scientists still have no way to forecast timing.
Experts stressed there is no evidence linking the three earthquakes directly, even though a major quake can subtly shift stress within the crust over long distances. What's clear, seismologists say, is that a region long primed for seismic violence has just been reminded, three times in two months, how differently the same restless fault system can behave.
