The Ice of the Southern Ocean

Regular sea ice observations off the coasts of Antarctica in the Mirny Station area have been made by the Soviet Antarctic Expedition since 1956. For eight years air ice reconnaissance over the Davis Sea has been made from Mirny Station during all the seasons of the year from the shore to the ice edge. During the voyages of the d/e ship O_B special observations on sea ice and icebergs have been made in the coastal zone of Antarctica. Physical properties, formation and desintegration of sea ice have been studied. The data obtained on sea ice peculiarities may be spread over a vast water area of the Southern Ocean. For many years the author has studied sea ice in the Arctic Ocean. The paper deals with general features of sea ice existence in the Antarctic and with differences. The formation and growth of ice from sea water both in the Arctic and Antarctic depend mainly upon air temperature and heat content in the sea. Disintegration and melting of ice in the Antarctic occur differently. Solar radiation, a great amount of diatoms included in the ice thickness and currents carrying ice out to the north into more warm waters play most important part here. The amount of old ice remaining in the Antarctic waters after the summer season is considerably less than in the Arctic waters. In the coastal zone of Antarctica due to ice cooling from ice cliffs, ice shelves and icebergs a great amount of intra-water ice crystals are formed. The crystals, coming to the surface, increase ice thickness. Due to great depths the width of the fast ice at the coasts of Antarctica is 20-30 miles, the width of the fast ice in the Arctic is hundreds of miles. A characteristic peculiarity of the Antarctic waters is the existence of icebergs. The icebergs have irregular spreading over the water area of the Southern Ocean. Soviet investigators have made an attempt to calculate the volume of fresh water in icebergs. It has been established that the annual runoff of fresh water from melting of icebergs is negligible and does not play any important part in the hydrological regime of the Southern Ocean. But icebergs have great influence on water temperature at coasts, on sea ice distribution and, consequently, on the conditions of the ship navigation in the Antarctic waters

The Soviet drifting station SP-3, 1954–55

In the early years of Soviet power, expeditions to the Barents and Kara Seas were organized, and this laid the foundations of navigation between the European part of the Soviet Union and the Siberian rivers Ob' and Yenisey. In the course of these voyages great quantities of goods were carried across the Arctic seas, which were to become important in the country's economy.</jats:p

Problems of the Arctic and the Antarctic, Issues 33-35.

Translated from Russian

Application of Landsat-7 satellite data and a DEM for the quantification of thermokarst-affected terrain types in the periglacial Lena-Anabar coastal lowland

Extensive parts of Arctic permafrost-dominated lowlands were affected by large-scale permafrost degradation, mainly through Holocene thermokarst activity. The effect of thermokarst is nowadays observed in most periglacial lowlands of the Arctic. Since permafrost degradation is a consequence as well as a signifi cant factor of global climate change, it is necessary to develop effi cient methods for the quantifi cation of its past and current magnitude. We developed a procedure for the quantifi cation of periglacial lowland terrain types with a focus on degradation features and applied it to the Cape Mamontov Klyk area in the western Laptev Sea region. Our terrain classifi cation approach was based on a combination of geospatial datasets, including a supervised maximum likelihood classifi cation applied to Landsat-7 ETM+ data and digital elevation data. Thirteen fi nal terrain surface classes were extracted and subsequently characterized in terms of relevance to thermokarst and degradation of ice-rich deposits. 78 % of the investigated area was estimated to be affected by permafrost degradation. The overall classifi cation accuracy was 79 %. Thermokarst did not develop evenly on the coastal plain, as indicated by the increasingly dense coverage of thermokarst-related areas from south to north. This regionally focused procedure can be extended to other areas to provide the highly detailed periglacial terrain mapping capabilities currently lacking in global-scale permafrost datasets