Past Disasters still haunt travelers “Could this whole world crack apart?” my three-year-old son asked me one day as we were walking along a beach on Coronation Island, a far-flung U.S. Forest Service designated wilderness area on the outer coast of southeast Alaska. We’d arrived here, to Egg Harbor, 90 miles south of Sitka, via our family’s small sailboat.  “Of course not,” I told him. “But right here, I mean. What if there was the biggest tsunami ever? Or an asteroid?” I raised my eyebrows at him. “What makes you ask?” Admittedly, our position looked precarious from a distance—on one side of us was an archipelago boasting some of the densest brown bear populations in the world; on the other was the North Pacific, whose fetch is intimidating even on a good day. If there ever was a part of the world that might swallow a person, this fit the…