Powerful back-to-back quakes hit Venezuela: What is 'doublet earthquake'
What's the story
Venezuela declared a state of emergency after two powerful earthquakes struck the country on Wednesday night. The United States Geological Survey (USGS) recorded the first quake at a magnitude of 7.2, centered about 160km west of Caracas. Less than a minute later, a second quake with a magnitude of 7.5 followed suit. The tremors caused widespread panic in the capital and were also felt in Colombia. As many as 34 people have died so far, with casualties expected to rise.
Seismic event
What are 'doublet' earthquakes?
The twin earthquakes were classified as a "doublet" by the USGS. This rare seismic phenomenon involves two major shocks of similar magnitude occurring close together in time from the same fault system or region. Unlike aftershocks, which are usually weaker than the main quake, doublets have multiple major shocks of similar strength. Such events are exceptionally uncommon because once a fault ruptures, they usually relieve enough stress to prevent another equally powerful rupture immediately afterward.
Venezuela
Why do earthquakes occur in northern Venezuela
Venezuela lies on one of South America's most active tectonic boundaries, where the Caribbean Plate slides eastward relative to the South American Plate. Northern Venezuela is crisscrossed by several major strike-slip fault systems, including the Bocono Fault, San Sebastin Fault, El Pilar Fault, and Moron Fault Zone. These interconnected fractures accumulate stress as the Caribbean Plate moves roughly two centimeters per year relative to South America.
Aftershocks
Aftershocks expected to gradually decline over coming weeks
The United States Geological Survey predicts continued seismic activity after the magnitude 7.5 earthquake. Experts expect around 26 aftershocks of magnitude four or greater in the first 24 hours, with an 89% probability of at least one reaching magnitude five or higher. This activity is expected to gradually decline over the coming weeks and months. The strongest earthquakes in Venezuela's recent history occurred in 1997 and 1967, killing 73 and 236 people, respectively.
Safety measures
US issues advisory for its citizens
Colombia's National Seismological Network received over 200 reports of tremors nationwide after the quake was felt as far away as Bogota. However, the Colombian disaster management agency UNGRD ruled out the possibility of a tsunami taking place. "NO tsunami, NO danger from a recent earthquake," the US National Tsunami Warning Center said in an X post.