A rare and extreme tsunami ripped across an Alaska fjord three years ago after 180 million tons of mountain rock fell into the water, driving a devastating wave that stripped shorelines of trees and reached heights over 600 feet, a large team of scientists documented Thursday.The October 2015 cataclysm in Taan Fiord in Southeast Alaska appears to have been the fourth highest tsunami recorded in the past century, and its origins - tied to the retreat of a glacier - suggest it’s the kind of event we may see more of due to a warming climate..The new study even bluntly...