Walter Clark of the National Ice Center delivers an ice condition report during a weather briefing aboard the Coast Guard Cutter Polar Star on Thursday, Jan. 4, 2018. The crew of the Seattle-based Polar Star is on its way to Antarctica in support of Operation Deep Freeze 2018, the U.S. military’s contribution to the National Science Foundation-managed U.S. Antarctic Program. U.S. Coast Guard photo by Chief Petty Officer Nick Ameen.