Boundaries between the continents of Earth Zemlya extend northward from the northern end of the Ural Mountains and are a continuation of that chain into the Arctic Ocean. While Novaya Zemlya was variously grouped with Europe or with Asia in 19th-century maps it is now usually grouped with Europe, the continental boundary considered to join the Arctic Ocean along the southern shore of the Kara Sea. The Russian Arctic archipelago of Franz Josef Land farther north is also associated with Europe. Europe ends in the west at the Atlantic Ocean, although Iceland and the Azores archipelago (in the Atlantic, between Europe and North America) are usually
North Asia Urals, covering the northern two thirds of the Ob Basin and extending onto the Angara Shield between the Yenisei River and the Lena River. There are legacies of mountain glaciation to be found on the east Siberian mountains, on the mountains of the Kamchatka Peninsula, on the Altai, on Tian Shan, and on other small areas of mountains, ice caps remain on the islands of Severnaya Zemlya and Novaya Zemlya, and several Central Asian mountains still have individual glaciers. North Asia itself has permafrost, ranging in depths from 30 to 600 metres and covering an area of 9.6 million km².