Thanks to 20 years of seismic data processed through one of the world’s most powerful supercomputers, scientists have created the first complete, 3D visualization of a mountain-size rock called the Kumano Pluton buried miles beneath the coast of southern Japan. They can now see that the rock could be acting like a lightning rod for the region’s megaquakes, diverting tectonic energy into points along its sides where several of the region’s largest earthquakes have happened.

Scientists have known about the pluton for years but were aware of only small portions of it. Thanks to new research by an international team of scientists led by the University of Texas at Austin, researchers now have a view of the entire subterranean formation and its effect on the region’s tectonics.

The findings will provide critical information for a major new Japanese government-funded project to find out whether another major earthquake is building in the Nankai subduction zone, where the pluton is located, said Shuichi Kodaira, director of the Japan Agency for Marine-Earth Science and Technology.

“We cannot predict exactly when, where, or how large future earthquakes will be, but by combining our model with monitoring data, we can begin estimating near-future processes,” said Kodaira, who was among the scientists who first spotted signs of the Kumano Pluton in 2006. “That will provide very important data for the Japanese public to prepare for the next big earthquake.”

The full extent of the Kumano Pluton was revealed using the LoneStar5 supercomputer at UT’s Texas Advanced Computing Center to piece together 20 years of seismic data into a single high-definition 3D model. Seismic imaging uses sound waves to create pictures of the Earth’s subsurface. Over the years, Japan’s vast network of sensors has collected millions of seismic recordings from thousands of locations along the Nankai subduction zone. The massive amounts of information was compiled into a single data set and turned it into a 3D model with the help of LoneStar5.