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
Severnaya Zemlya as Arctic lemming, which is present on all of the large islands and, in some places has been recorded to reach a density of 500 per km (1,300 per sq mi). The Arctic fox ("Alopex lagopus") has been known to den on the islands, with several hundred observed in the 1980s. Other mammals occasionally observed include the wolf ("Canis lupus"), the polar bear ("Ursus maritimus"), ermine ("Mustela erminea"), Arctic hare ("Lepus timidus"), and reindeer ("Rangifer tarandus"). The discovery of Severnaya Zemlya is the subject of Veniamin Kaverin's novel "The Two Captains" as well as its stage adaptation, "Nord-Ost". Severnaya Zemlya