Contagious Quakes

Subduction zones can "infect" other tectonic plates

- Evan Howell

SUBDUCTION ZONES, where one tectonic plate dives underneath another, drive the world's most devastating earthquakes and tsunamis. How do these danger zones come to be? A study in Geology presents evidence that subduction can spread like a contagion, jumping from one oceanic plate to another-ahypothesis previously difficult to prove.

This result "is not just speculation," says University of Lisbon geologist João Duarte, who was not involved in the research. "This study builds an argument based on the geological record."