Why the Myanmar earthquake was so destructive

Subscribe to enjoy similar stories. The powerful 7.7-magnitude earthquake that struck central Myanmar on Friday was one of the most powerful in the region in years. While the full extent of the damage remains unclear, the United States Geological Survey says it is likely that more than 10,000 people died and that economic losses could exceed the gross domestic product of Myanmar, a poor country engulfed in a bloody civil war.

It may take days or weeks before an accurate death toll is established, as many people are buried beneath rubble. Here is what to know about the science behind the earthquake and why experts fear the damage could be extensive. The earthquake in Myanmar was likely caused by “strike-slip faulting," in which tectonic plates—massive slabs of rock on the Earth’s crust that are always slowly moving—brush horizontally past each other.

It is different from so-called “subduction" earthquakes, in which one tectonic plate is thrust beneath another. Scientists believe this quake occurred in the vicinity of a long, straight fault that runs through the middle of the country known as the Sagaing Fault, which some experts have compared to the San Andreas Fault in California. While Myanmar isn’t in the so-called “Ring of Fire"—a famously seismic arc around the Pacific basin that includes Japan and Indonesia—several plates converge in the country, including the India and Eurasia plates, and earthquakes are common.

The USGS says that there have been six other magnitude-7, or larger, earthquakes in the vicinity of the latest one since 1900. In 1990, an earthquake in the area caused 32 buildings to fall, and dozens were killed by another quake in 1988. But Myanmar had not in recent times suffered a mass-casualty