A new core drilled through an ice field on the Antarctic Peninsula should contain ice dating back into the last ice age. If so, that will give new insight into past global climate changes. The expedition in early winter to the Bruce Plateau, an ice field straddling a narrow ridge on the northernmost tongue of the southernmost continent, yielded a core that was 1,462 feet long, the longest yet recovered from that region of Antarctica. Old ice can contain bubbles of trapped air from long ago. That air represents, unchanged, what the air composition was like thousands of years ago. There may be other frozen clues in the water itself