Air-hydrate crystals in deep ice-core samples from Vostok Station, Antarctica
Air-hydrate crystals in deep ice-core samples from Vostok Station, Antarctica
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南极洲沃斯托克站深层冰芯样本中的空气水合物晶体
DOI：
10.3189/s0022143000003828
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发表时间：
1994
影响因子：
3.4
通讯作者：
P. Duval
中科院分区：
文献类型：
--
作者：
T. Uchida;T. Hondoh;S. Mae;V. Lipenkov;P. Duval
摘要利用南极东方站34个深冰芯样品对空气水合物晶体进行了显微观察。从1050和2542米之间的深度，这对应于威斯康星州/Sangamon/伊利诺伊州冰的样品。结果表明，天然气水合物的数量和体积随气候变化而变化。间冰期冰中空气水合物的体积浓度比冰川冰中的大30%左右。在间冰期冰中，空气水合物的数量浓度约为冰期冰的一半，平均体积约为冰期冰的3倍。空气水合物晶体在冰盖中生长，约6.7 × 10−12 cm 3年-1，以补偿较小晶体的消失。空气水合物的体积浓度与总气体含量之间存在一个几何关系式，其中含有一个比例参数α。在1250米以下没有发现气泡的地方，α的平均值约为0.79。这与在格陵兰岛Dye 3获得的1 500米岩芯中空气水合物结晶位置占有率的实验测定值相吻合（Hondoh等人，1990年）。在许多样品的α深度剖面中，间冰期冰的α比冰期冰的小30%左右。
Abstract Microscopic observation of air-hydrate crystals was carried out using 34 deep ice-core samples retrieved at Vostok Station, Antarctica. Samples were obtained from depths between 1050 and 2542 m, which correspond to Wisconsin/Sangamon/Illinoian ice. It was found that the volume and number of air-hydrate varied with the climatic changes. The volume concentration of air-hydrate in the interglacial ice was about 30% larger than that in the glacial ice. In the interglacial ice, the number concentration of air-hydrate was about a half and the mean volume of air-hydrate was nearly three times larger than that in the glacial-age ice. The air-hydrate crystals were found to grow in the ice sheet, about 6.7 × 10−12 cm3 year-1, in compensation for the disappearance of smaller ones. The volume concentration of air-hydrate was related to the total gas content by a geometrical equation with a proportional parameter α. The mean value of α below 1250 m, where no air bubbles were found, was about 0.79. This coincided with an experimentally determined value of the crystalline site occupancy of the air-hydrate in a 1500 m core obtained at Dye 3, Greenland (Hondoh and others, 1990). In the depth profile of calculated α for many samples, α in the interglacial ice was about 30% smaller than that in the glacial-age ice.