Permafrost Formation Time
Permafrost Formation Time
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永久冻土形成时间
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
V. Lunardini
中科院分区：
文献类型：
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作者：
V. Lunardini
摘要：永久冻土的年龄与土壤系统冻结所需的时间密切相关，因为永久冻土必须至少与形成时间一样古老。冻融循环会使冻结速率与龄期之间的关系复杂化。一个模型的基础上纯传导传热与冻融是用来预测所需的时间为一个给定的厚度的冻土发展，无论是异源或同生。形成时间是长期地热梯度（解冻土壤的初始温度）的冻融热性质的比率，和多年冻土的上表面的温度历史（高于空气温度）的函数。这个简单的理论可以产生通用的图表，预测给定厚度的pennafrost的形成时间。现实的土壤性质的比率和古温度的情况下，将导致估计的形成时间的永久冻土为特定的网站。该模型表明，深层永久冻土（超过1500英寸）需要形成时间的顺序完整的第四纪。（MM）
Abstract : The age of permafrost is closely linked to the time required for soil systems to freeze, since the permafrost must be at least as old as the formation time. Cycles of freeze-thaw will complicate the relation between the freeze rate and the age. A model based on pure conduction heat transfer with freeze-thaw is used to predict the time required for a given thickness of permafrost to develop, either heterogenetically or syngenetically. The formation time is a function of the long-term geothermal gradient (initial temperature of the thawed soil) the ratios of the frozen to thawed thermal properties, and the temperature history of the upper surface of the permafrost (higher than the air temperature). The simple theory allows universal graphs to be produced that predict the formation time for a given thickness of pennafrost. Realistic soil property ratios and paleotemperature scenarios will then lead to estimates of the formation time of permafrost for a specific site. The model indicates that deep permafrost (more than 1500 in) requires formation times on the order of the complete Quaternary Period. (MM)