Tree rings reveal a new kind of earthquake threat to the Pacific Northwest

Tucson AZ (SPX) Sep 28, 2023

In February, a 7.8-magnitude earthquake shook the Turkey-Syria border, followed by one nearly as large nine hours later. Shallow faults less than 18 miles beneath the surface buckled and ruptured, causing violent focused quakes that leveled thousands of buildings and killed tens of thousands. Similar shallow faults ruptured about 1,000 years ago in the Puget Lowlands in western Washington,