Scientists at Woods Hole Oceanographic Institution and the University of Minnesota have found that California’s drought of 2012 to 2014 is the worst seen there in 1,200 years, according to a release. Their investigation relied on tree-ring samples.
Trees under study — California old blue oaks — are particularly sensitive to moisture changes, scientists say. Because they can grow in some of the state’s driest areas, they make excellent gauges of rainfall abundance or scarcity over time.
Investigators used the tree-ring data, as well as climate data from the National Oceanic and Atmospheric Administration, to reconstruct rainfall patterns going back to the 13th century. By throwing in analyses on temperature changes and water shortages, they were able to conclude that the two-year drought period has been one of the worst for the region.
Top image: Samples from logs can be used to trace drought levels back through time. (Credit: Daniel Griffin)