White Death by Clive Cussler

Hailed as a hero for the new millennium, Austin is the leader of NUMA(r)'s Special Assignments Team-and the threat before him now is definitely special. A confrontation between a radical environmentalist group and a Danish cruiser has forced Austin and colleague Joe Zavala to come to the rescue of a shipful of trapped men; but when the two of them investigate further, they discover that something far more sinister is at work.