Nordenskiöld was a Finnish-born Swedish geologist, mineralogist, geographer, and explorer who wrote several valuable books on geography, cartography, and travel. In 1858, he settled in Stockholm and became professor and curator of mineralogy at the Swedish State Museum. He led several expeditions to the Arctic island of Spitsbergen between 1864 and 1873 and later became the first to sail from Norway to Alaska through the Northeast Passage. He was also the first to break through what ice barrier? Discuss