Venezuela was hit with its largest tremors in more than a century on Wednesday evening, toppling buildings and claiming more than 100 lives. The event, according to the US Geological Survey, was a rare phenomenon called a “doublet” that contained not one but two major earthquakes.

Understanding Doublets

Doublets occur when two quakes of similar magnitude happen in close succession — potentially causing more damage than a single quake. In this instance, a 7.2-magnitude earthquake shook northern Venezuela and was followed by a 7.5-magnitude quake only 39 seconds later.

Some researchers speculate that additional data could reveal that the event was caused by one large earthquake instead of a duo. The difference between one long earthquake and a twinned pair may not matter in terms of human outcomes, but it could teach scientists a lot about this uncommon occurrence and predicting the severity of earthquakes.

Scientific Analysis

Earthquakes occur when two moving tectonic plates become stuck, build tension and then suddenly release the pent-up energy. Wednesday’s tremors occurred on the boundary between the Caribbean and South American plates, which have been slipping at a rate of around 20 millimeters per year.

Northern Venezuela often experiences large, damaging earthquakes, but, over the past century, the region has only experienced seven earthquakes of magnitude 6 or greater. The seismic data is ambiguous, and it may take some days for seismologists to really piece out the event.

Original reporting: El Paso News (HLL/CB) — read the source article.