Arctic exploration involves physically exploring the Arctic region and has been occurring for over 330 years. It is undertaken by merchant explorers, geographers, and others to expand territory, study climate change, glaciers, geology, ocean chemistry, and discover natural resources like mines, fisheries, fresh water, and hydro power. Some of the first descriptions from Arctic exploration in 330 BC by Pytheas of Massalia included the midnight sun, aurora borealis, and polar ice.