Venezuela and its capital, Caracas, were rocked by two massive earthquake pulses on June 24, 2026, just seconds apart. The shaking from the magnitude 7.2 and 7.5 events caused buildings to collapse in cities across the northern part of the country, killing more than 1,400 people and trapping many more, government officials reported.University of Southern California geophysicist Sylvain Barbot explained what’s known about the earthquake pulses so far, what risks are still ahead and why Californians should pay attention.How many earthquakes hit Venezuela, and why did it see so much damage?Earthquakes are natural phenomena that typically happen at the boundaries of Earth’s tectonic plates. These plates, which make up the Earth’s crust, are tens of miles thick and carry the oceans and continents. They are slowly moving, but not in a smooth, consistent way.AdvertisementAdvertisementVenezuela sits along the boundary between two of these plates: The South American plate and the Caribbean plate. As they slide past each other, these plates can stick, building up resistance before eventually having a catastrophic failure that generates an earthquake.Venezuela sits on the South American plate, adjacent to the Caribbean plate, which underlies the Caribbean Sea. The circles indicate large earthquakes of magnitude 5.5 and higher from 1900 to 2019. Most are on or near the plate margins. U.S. Geological SurveyThere were two big pulses of seismic activity within 39 seconds of each other on June 24, 2026, both over magnitude 7. They could have been separate events or a single earthquake with two pulses. Scientists don’t yet know because we’re still analyzing the data.Two separate earthquakes is plausible. In 2023 there was an earthquake “doublet” in Turkey, where two magnitude 7-plus earthquakes happened within eight hours of each other. In that case, it was clearly two events.In Venezuela the pulses were just a few seconds apart. There have been earthquakes of this magnitude in the past that ruptured different segments of very long faults, creating the appearance of two different earthquakes but that were actually ruptures from the same event.What triggers destructive earthquakes like this?Earthquakes are controlled by how rocks resist shear and stress. The stress can build up over years or decades until it overcomes the strength of the rocks, making them break. When that happens, the stress propagates and the rupture grows.AdvertisementAdvertisementThat’s not a gradual motion. Within seconds, the plates quickly move, causing an earthquake. This happens several miles underground, where the temperature and pressure are both very high.That action is difficult to reproduce in a laboratory and involves many processes, from mechanics to chemistry to the motion of fluids. But the outcome is simple: There is a rupture that involves the sliding of rocks past one other that creates a surface rupture that breaks everything in its path, causing damage.Are there similarities between the fault system in Venezuela and California’s San Andreas?The faults involved in Venezuela’s earthquake and California’s San Andreas are very similar. They are known as transform faults, where this strike-slip motion happens as plates slide horizontally past each other.Even the rates of motion are quite similar. In Venezuela the boundaries move past each other at about 0.8 inches (20 millimeters) per year on average. Along the San Andreas Fault it’s slightly faster, about 1.2 inches (30 millimeters) per year.How strike-slip movement happens during a large earthquake in a transform fault, similar to the San Andreas in California. U.S. Geological SurveyThey also create large magnitude earthquakes at similar frequencies. On the San Andreas Fault, scientists expect on average a large earthquake of magnitude 7 or above every 170 years or so, with the timing varying along the fault. However, this is not clockwork – it can be much more frequent or much less.AdvertisementAdvertisementSouthern California’s last “big one” was the Fort Tejon earthquake of 1857, a powerful magnitude 7.9. A recent study suggested the stress along the southern San Andreas is stronger now than it has been in at least 1,000 years. If the assumptions of the work are correct, it ma …
