National Geographic : 1976 Nov
MAGNIFIED1,800 TIMES MAGNIFIED3,000 TIMES Tiny pieces in a global puzzle: Dust particles seen by a scanning electron microscope can tell of climate that existed when they fell on the West Antarctic ice sheet near Byrd Station. Iron in a grayish speck (top) indicates it probably blew from the nearby Transantarctic Mountains 5,000 years ago during a warm period of low ice cover. The spherical particle may be part of an iron meteorite that entered the atmosphere 10,000 to 14,000 years ago. Two glassy particles (bottom) mark volcanic periods some 15,000 and 18,000 years ago, dated by counting seasonal layers. LONNIEG. ANDELLENM . THOMPSON,INSTITUTEOF POLARSTUDIES, OHIOSTATEUNIVERSITY(ALL AT LEFT);WILLIAMR. CURTSINGER(ABOVE) Opening a diary written in ice, a volcano in 1969 and 1970 split deep rifts in a glacier on Deception Island near the Antarctic Peninsula. By reading alternate layers of winter snow and summer wind blown ash, scientists can compare the region's climatic change with Northern Hemisphere data.