Chapter Two Modern Physiography, Hydrology, Climate, and Sediment Input

Abstract

Publisher Summary This chapter presents the information on bathymetry and physiography of the Arctic Ocean. The central Arctic Ocean with its deep basins is surrounded by continental massifs and the shallow continental shelves. The only break in this ring of continental crust is the Fram Strait between northeastern Greenland and northwestern Svalbard, the only deep-water connection with the world ocean via the Atlantic Ocean. The Arctic Ocean proper is divided into two major sub-basins: (1) the Eurasian Basin bounded by the Lomonosov Ridge and the shallow shelves of the Barents, Kara, and Laptev seas and northern Greenland, and (2) the Amerasian Basin bounded by the Lomonosov Ridge and the shelves of the East Siberian, Chukchi, and Beaufort seas and the Canadian Arctic Archipelago. Based on the distribution of potential temperature, salinity, and density, the Arctic Ocean's hydrographic structure consists of three main water masses: (1) the upper waters, (2) the intermediate waters (Atlantic Layer), (3) and the deep waters. An important phenomenon of the Arctic Ocean is the permanent sea-ice cover with its strong seasonal variation in the marginal (shelf) areas. Marine bio-production in the Arctic and Subarctic is based primarily on microscopic unicellular algae (phytoplankton) in the water column and microalgae associated with ice. One of the main characteristics of the Arctic Ocean is its huge river discharge. Fine-grained particles (as well as organic matter and contaminants) may be transported by winds into the Arctic Ocean.