Sources and mechanisms of seawater freshening at the Tsivol’ki and Sedov’ bays (Novaya Zemlya): isotope (δD, δ18О) data

Three-year monitoring of isotope (δD, δ 18 О) parameters in the waters of the Sedov’ and Tsivol’ki bays (Novaya Zemlya) was carried out. The fresh waters of the bays are originated from several sources (continental runoff, precipitations, and waters going from the archipelago). The freshening extent and sources of fresh waters are different at the different depth. The δD and δ 18 О values varies only in the surface waters which contains more than 30% of fresh component. In 2015 the surface waters of Sedov’ bay were represented by Ob’ river waters, and the surface waters of Tsivol’ki bay were enriched by the runoff from Novaya Zemlya. Deep waters in both bays show signs of desalination by high latitude atmospheric precipitations. These waters can be transferred to the southeast coast of Novaya Zemlya through the trenches of St. Anne and Voronin. The difference in the freshening mechanisms of the waters of Sedov and Tsivolka bays is determined by different bottom morphologies and different degrees of free water exchange with the Kara Sea.