Permafrost and Little Ice Age glacier relationships, Posets Massif, Central Pyrenees, Spain
Permafrost and Little Ice Age glacier relationships, Posets Massif, Central Pyrenees, Spain
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永久冻土层和小冰河时代冰川的关系，西班牙中部比利牛斯山脉波塞茨地块
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发表时间：
2004
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通讯作者：
J. González
中科院分区：
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作者：
R. Lugon;R. Delaloye;E. Serrano;E. Reynard;C. Lambiel;J. González
本文报道了两个冰川小冰期（LIA）前田的地电调查和热测量结果，为比利牛斯山脉多年冻土的研究做出了贡献。目的是评估位于这一前冰川环境中的沉积体（碎屑岩、冰川和冰碛沉积物）的内部组成。地面冰的勘探使用了两种直流电阻率技术：垂直电测深和固定伪深度的电阻率测绘。在薄的（1 - 2米）未冻结层下检测到1至25 MΩ m的极端比电阻率，表明存在巨大的冰层，肯定是埋藏的冰川冰。这种冰川起源的冰可能覆盖了以前的永久冻土，即一层更厚的永久冻结沉积物。在沉积物上测量的低地下温度表明，自LIA末期或全新世早期冰川推进以来，埋藏的冰川冰可能一直保存在永久冻土层的顶部。这种地层学表明，在小冰期，冰川和预先存在的永久冻结沉积物（永久冻土）是接触的。版权所有©2004 John Wiley & Sons， Ltd
This paper contributes to the study of permafrost in the Pyrenees by reporting geoelectrical investigations and thermal measurement on the Little Ice Age (LIA) forefields of two glaciers. The aim was to assess the internal composition of sedimentary bodies (debris rock glaciers and moraine deposits) located in this proglacial environment. Ground ice was prospected using two DC resistivity techniques: vertical electrical soundings and resistivity mapping at a fixed pseudo‐depth. Extreme specific resistivities ranging between 1 and 25 MΩ m were detected under a thin (1–2 m) unfrozen layer, indicating the presence of a massive ice layer, certainly buried glacier ice. This ice of glacial origin probably covers former permafrost bodies, i.e. a much thicker layer of perennially frozen sediments. Low subsurface temperatures measured on the deposits indicate that buried glacier ice could have been preserved on top of permafrost since the end of the LIA or earlier Holocene glacier advances. This stratigraphy demonstrates that glaciers and pre‐existing perennially frozen sediments (permafrost) were in contact during the LIA. Copyright © 2004 John Wiley & Sons, Ltd.