The first Russian expedition was carried out in 1901, when the icebreaker "Yermak" traveled to the islands. The next expedition, led by hydrologist Georgy Sedov, embarked in 1912 but did not reach the archipelago until the following year because of ice. Among its scientific contributions were the first snow measurements of the archipelago, and the determination that changes of the magnetic field occur in cycles of fifteen years. It also conducted topographical surveys of the surrounding area. Scurvy set in during the second winter, killing a machinist. Despite lacking prior experience or sufficient provisions, Sedov insisted on pressing forward with a march to the pole. His condition deteriorated and he died on 6 March.