The summer of 2014 was a strange one in the Chukchi Sea. The Arctic waters, historically icebound much of the year, were oddly free of ice. There was so little ice that 35,000 walruses had beached themselves on a northwest Alaska shoreline after failing to find floes to feed from. One morning in September, oceanographer Jim Thomson was on a research trip onboard the vessel Norseman II, hundreds of miles from land, when he noticed something else that was strange: some of his shipmates were seasick.