Physical, chemical and biological processes in Lake Vostok and other Antarctic subglacial lakes
Physical, chemical and biological processes in Lake Vostok and other Antarctic subglacial lakes
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沃斯托克湖和其他南极冰下湖泊的物理、化学和生物过程
作者：
M. Siegert;J. Ellis;M. Tranter;C. Mayer;J. Petit;A. Salamatin;J. Priscu
在南极冰盖下已经发现了70多个湖泊。虽然没有直接对这些湖泊的水进行采样，但对这些湖泊中最大的湖沃斯托克湖上方冰盖底部的湖冰冻结（增生）的分析允许对湖水化学进行推断，并揭示了少量的微生物。这些发现表明，沃斯托克湖是一个极端但可行的生命环境。所有冰下湖泊都处于高压（约350个大气压）、低温（约-3 °C）和永久黑暗的环境中。因此，任何存在的微生物都必须使用化学源来为生物过程提供动力。重要的是，溶解氧至少在湖面上是可用的，与融化的基底冰川冰释放的空气水合物平衡。在沃斯托克湖的积冰中发现的微生物是相对现代的，但古老的湖底沉积物的可能性导致了在冰下湖泊底部存在非常古老的生物群的可能性。
Over 70 lakes have now been identified beneath the Antarctic ice sheet. Although water from none of the lakes has been sampled directly, analysis of lake ice frozen (accreted) to the underside of the ice sheet above Lake Vostok, the largest of these lakes, has allowed inferences to be made on lake water chemistry and has revealed small quantities of microbes. These findings suggest that Lake Vostok is an extreme, yet viable, environment for life. All subglacial lakes are subject to high pressure (∼350 atmospheres), low temperatures (about -3 °C) and permanent darkness. Any microbes present must therefore use chemical sources to power biological processes. Importantly, dissolved oxygen is available at least at the lake surface, from equilibration with air hydrates released from melting basal glacier ice. Microbes found in Lake Vostok's accreted ice are relatively modern, but the probability of ancient lake-floor sediments leads to a possibility of a very old biota at the base of subglacial lakes.