Russian Empire Bolsheviks followed in 1918. The administrative boundaries of European Russia, apart from Finland and its portion of Poland, coincided approximately with the natural limits of the East-European plains. In the North it met the Arctic Ocean. Novaya Zemlya and the Kolguyev and Vaygach Islands also belonged to it, but the Kara Sea was referred to Siberia. To the East it had the Asiatic territories of the Empire, Siberia and the Kyrgyz steppes, from both of which it was separated by the Ural Mountains, the Ural River and the Caspian Sea — the administrative boundary, however, partly extending into Asia on
Severnaya Zemlya USSR some features of the geography of Severnaya Zemlya that had been previously named in solidarity with German Communism saw their names altered to Russian or neutral-sounding names – e.g. Cape Unslicht becoming "Mys Peschanyy" and "Proliv Yungshturm" Yuny Strait. During the Cold War, the islands of Severnaya Zemlya continued to be studied by a team of geologists from NIIGA (the Scientific Research Institute of Arctic Geology) in St. Petersburg. Between 1948 and 1954 a comprehensive geological map was compiled under B. Kh. Egiazarov. Also more accurate maps were drawn by means of cartographic data gathered from aerial photography surveys.