Applicability of electrical resistivity tomography monitoring to coarse blocky and ice‐rich permafrost landforms
Applicability of electrical resistivity tomography monitoring to coarse blocky and ice‐rich permafrost landforms
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DOI：
10.1002/ppp.652
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发表时间：
2009-07
影响因子：
5
通讯作者：
C. Hilbich;L. Marescot;C. Hauck;M. Loke;R. Mäusbacher
中科院分区：
文献类型：
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作者：
C. Hilbich;L. Marescot;C. Hauck;M. Loke;R. Mäusbacher
由于电阻率对比度强和接触电阻高，对粗糙块状和富冰多年冻土区的电阻率层析成像（ERT）数据进行反演和解释具有挑战性。为了评估ERT监测（ERTM）期间的时间变化，必须将相应的反演伪影与真实的地下变化分离。评估技术用于分析来自岩石冰川的ERTM数据集，包括合成建模，调查深度指数技术和所谓的分辨率矩阵方法。这些方法的应用导致逐步识别不可靠的模型区域，从而提高解释的时间电阻率变化。一个重要的结果是，具有强电阻率对比度和高电阻特性的模型区域的电阻率值通常具有关键的可靠性，因此，岩石冰川冰芯内或冰芯下的电阻率变化不应被解释为永久冻土信号。相反，ERTM可以检测到永久冻土层中大量地面冰变暖的长期退化现象。版权所有© 2009约翰威利父子有限公司。
The inversion and interpretation of electrical resistivity tomography (ERT) data from coarse blocky and ice‐rich permafrost sites are challenging due to strong resistivity contrasts and high contact resistances. To assess temporal changes during ERT monitoring (ERTM), corresponding inversion artefacts have to be separated from true subsurface changes. Appraisal techniques serve to analyse an ERTM data set from a rockglacier, including synthetic modelling, the depth of investigation index technique and the so‐called resolution matrix approach. The application of these methods led step by step to the identification of unreliable model regions and thus to the improvement in interpretation of temporal resistivity changes. An important result is that resistivity values of model regions with strong resistivity contrasts and highly resistive features are generally of critical reliability, and resistivity changes within or below the ice core of a rockglacier should therefore not be interpreted as a permafrost signal. Conversely, long‐term degradation phenomena in terms of warming of massive ground ice at the permafrost table are detectable by ERTM. Copyright © 2009 John Wiley & Sons, Ltd.