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
12th Chief Directorate Another task of the 12th GU MO is to prevent so-called "nuclear terrorism," but this is a relatively modern task, which did not exist formerly. Besides these nuclear arsenal bases, the 12th Chief Directorate maintains several nuclear weapons research institutes in Moscow and in Sergiev Posad, near Moscow, with their subsidiaries located at nuclear testing grounds in Semipalatinsk-21 and on Novaya Zemlya Archipelago, and in several other cities (Saint Petersburg, for example). It also maintains a separate research institute tasked with developing nuclear explosions detection technology. Another function of the 12th GU MO is to serve as a link between