Complex sentence: The glacier was photographed from the air in 1940 by the United States Antarctic Service, and was charted in 1947 by the Falkland Islands Dependencies Survey, who named it for Professor Hans Wilhelmsson Ahlmann, a Swedish glaciologist and geographer.
Split into simpler sentences: The glacier was photographed from the air in 1940 by the United States Antarctic Service. Charted in 1947 by the Falkland Islands Dependencies Survey, who named it for Professor Hans Wilhelmsson Ahlmann, a Swedish glaciologist and geographer.