Earthquakes can help forests grow

October 22, 2021

Earthquakes can tear down buildings, but they can also build up forests—at least for a little while. New research shows strong quakes can help trees grow by driving extra water into the soil surrounding their roots. These fleeting growth spurts leave signatures in wood cells that could also be used to better detect and date ancient earthquakes.

“This is really, really a new frontier in [timing earthquakes] on a more precise scale than a year,” says Irina Panyushkina, a tree ring expert at the University of Arizona who was not involved in the study.

University of Potsdam hydrologist Christian Mohr didn’t set out to find a link between seismicity and tree growth. But his research took a turn after the magnitude 8.8 Maule earthquake in Chile in 2010. It shook the river valleys where he was studying sediment transport—and it shook him.

“I was there during the earthquake, which was pretty scary,” says Mohr, who sheltered in a doorframe as the waves rocked his wooden cabin in the middle of the night. The earthquake and ensuing tsunami devastated parts of coastal Chile, killed hundreds, and directly affected more than 2 million people.

The method could help scientists peer into the past, Panyushkina says. She anticipates the method might one day help researchers identify short-term disturbances like earthquakes that occurred thousands of years ago.