What links tree rings and avalanches? Molly Tankersley explains, for Scientific American (@sciam). In Alaska, researchers are studying the rings to learn about the snowslides to protect Juneau, which has the country’s highest urban avalanche potential. Molly is a communications specialist at the University of Alaska Climate Adaptation Science Center. Follow @mollytankersley and Molly’s blog. image: Andrei Terenchenko Flickr (CC BY 2.0)