On the Air: April 12, 2015
The Cascadia Subduction Zone is a 1,000-kilometer-long subduction zone stretching from California to British Columbia. Credit: National Oceanic and Atmospheric Administration

When most people talk about the “next big earthquake,” they usually mean a major temblor along the San Andreas Fault in southern California. But research over the last few decades suggests that the next big one might strike a little farther north — from northern California to southern British Columbia.

In Print: April 1, 2015
Almost one million years ago, North Atlantic currents and northern hemisphere ice sheets underwent changes. Credit: NASA

Just under a million years ago, a major pattern in Earth’s climate suddenly changed. Instead of having an ice age about every 41,000 years, the cycle switched to about every 100,000 years – and the cold periods had even lower average temperatures than the previous ones. What caused the interval between ice ages to double?