Complex sentence: It was discovered by a party under J. Gunnar Andersson, of the Swedish Antarctic Expedition, 1901--04, and was named by Otto Nordenskiöld, the leader of that expedition, for Lieutenant S.A. Duse.
Split into simpler sentences: It was discovered by a party under J. Gunnar Andersson, of the Swedish Antarctic Expedition, 1901-04. Duse Bay was named by Nordenskjold, leader of the Swedish Antarctic Expedition, for Lieutenant S.A. Duse.