Studies on the permafrost occurrence related to the past climatic changes in Antarctic regions

本文作者在末次冰期和现今气候条件下对南极马兰比奥岛进行了多年冻土的联合野外考察，利用各种气象要素测定了当地的气候条件，并根据实测资料将当地的典型气候条件定义为极地沙漠气候。年平均气温估计为-9.5摄氏度。多年冻土深度定义为多年冻土表，通过地震测深和测量多年冻土地面上的地面电介电常数来估算。多年冻土层的深度在上层（Meseta +200 m）为128 m，在中层（Sub-Meseta +60 m）为44 m，在下层（Larsen +5 m）为28 m。活动层深度估计为80厘米或更少的上层。冰楔形成的观察和苔原多边形的模式进行了测量，并绘制在地形图上。用岩石破碎机检查了冰楔的剖面。对冰楔中的冰进行了化学分析，发现冰中含有高浓度的盐，分析了马兰比奥岛多年冻土的成因和分布，讨论了末次冰期气候变化的影响。长期的实地测量仍在岛上不同地点进行。

Present authors conducted the joint field expedition in Marambio island, Antarctica related to the peramfrost occurrence during last glaciation and under present climatic condition.The local weather conditions were measured by various elements and typical climatic condition was defined as polar desert climate based upon measured data. The mean annual temperature is estimated as -9.5 degrees in Cesius. Permafrost depths defined as permafrost table were estimated by the seismic sounding and the measurements of electrical resistivility of the grounds on the surface of the permafrost ground.General topography is characterized as marine terraces in different levels. The depths of permafrost are 128m deep at the upper level (Meseta +200m), 44m deep at middle level (Sub-Meseta +60m) and 28m deep at lowest level (Larsen +5m). The active layer depth is estimated as 80cm or less at the upper level.Ice-wedge formations are observed and the patterns of tundra-polygons were measured and plotted on the topographic maps. The profiles of ice-wedge were examined by means of rock breakers. The chemical analysis of the ice from ice-wedge were conducted and very high concentrations of salts into ice were reported.The genesis and occurrences of permafrost in Marambio island are under analysis and effects of climatic changes during last glaciation is discussed by present authors. Long term field measurements are still undergoing on-the-spot at various locations in the island.