The 15 dogs in his team move carefully. Despite freezing temperatures in late March, the ice has broken up, making travel dangerous. "The sea ice used to be three feet thick here," Danielsen says. "Now it's only four inches thick."The 15 dogs in his team move carefully. Despite freezing temperatures in late March, the ice has broken up, making travel dangerous. "The sea ice used to be three feet thick here," Danielsen says. "Now it's only four inches thick.