The Earth is tearing itself apart near Vancouver Island in the Pacific Northwest
Subduction zones can look permanent on a map. They run for hundreds or thousands of miles, haul oceanic crust into the mantle, feed volcanoes, and store the strain that drives some of Earth’s most dangerous earthquakes. But they do not last. That basic fact has left geologists with a stubborn question. If subduction keeps pulling plates downward with such force, what actually stops it? A new study points to an answer off Vancouver Island, where part of the Cascadia subduction system appears to be coming apart in real time. Instead of shutting down in one dramatic break, the research suggests, a subduction zone can fail by tearing itself into smaller pieces, losing strength segment by segment until the larger system grinds toward a halt. “Getting a subduction zone started is like trying to push a train uphill, it takes a huge effort,” said Brandon Shuck, lead author of the study and an assistant professor at Louisiana State University, who conducted the research while he was a postdoctoral fellow at Columbia University’s Lamont-Doherty Earth Observatory. “But …
