| 摘要: |
| 拉斯曼丘陵区的湖泊均为淡水湖,总数近150个,湖泊总面积6.3km2,占陆地总面积的3.15%。东部地区湖泊数量少但多深大湖,西部地区数量多但多浅小湖。湖泊地貌发育初始,A1/Ac之值较大,湖岸地貌形态不发育,全年封冻期长达300天,限制了湖水动力对地貌和沉积物形成的作用强度,冰雪融水量与湖面蒸发量控制了湖水平衡和湖面变化过程。湖积物厚度小,颗粒粗,分选差,风力混杂堆积作用明显。夏季水温变化复杂,并常有明显的逆温现象。水体pH值介于6.0~8.0之间,Na+占绝对优势。 |
| 关键词: 淡水湖泊 拉斯曼丘陵 东南极 |
| DOI：10.18307/1995.0301 |
| 分类号: |
| 基金项目:国家南极考察委员会;中国科学院地理研究所所长基金 |
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| Lakes of the Larsemann hills, east Antarctica |
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Li Shuanke
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Institute of Geography, Chinese Academy of Sciences and the State Planning Committee of P. R. China, Beijing 100101
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| Abstract: |
| The Larsemann Hills, located at 69°17'~69°28'S and 7Acl00'~76°30'E, consists of a series of granite and gneiss peninsulas and islands extending into Prydz Bay. The hilly area is about 200 km2, with a lake area of mere 6.3 km2. In the hills are over freshwater lakes ranging from small ponds less than 1m deep to glacial lakes up to 0.13 km2 and 38m deep. Lakes in this region distribute unevenly, i. e., there are 81 lakes in the Storness Peninsula and 36 lakes in the Mirror Peninsula. The lake density of the hills decreases from west to east. The lake basin has its own characteristics, such as:the ratios of the lake area to catchment area are over 1.0 in several lakes. and the undevelopment of lakeshore means that they belong to young lakes. The lakes are generally shallow ponds and snow-and-ice-deepened basins that thaw (or partially thaw) from December to February, or in some cases, remain permanently frozen. Sedimentary accumulations in the lakes are thin, and the dominant sediment type is coarse gravel in a number of lakes. Fluvioglacial sediments and aeolian sediments are the main composition, while pure lacustrine sediments are very thin and rare. Variations m the characteristics of the lakes reflect deglaciation history, proximity to the continental ice margin and exposure to the ocean. The main source of the water comes from snow and ice melt, so that the water temperature usually changes within a narrow range of 0.2℃/m, but near the beds of some lakes does a sharp increase occur. The water has near neutral pH values. The ionic order is Na+ > Mg2+ > Ca2+ > K+. |
| Key words: Freshwater lakes Larsemann Hills East Antarctica |
