Abstract The western and eastern Dead Sea (DS) shores are hit by intensive sinkhole collapse during the last 30 years. The first researchers have considered a piping model of sinkhole formation, based on washing out fines by underground flows. Then, it was proved by numerous boreholes and seismic refraction surveys that sinkholes along western shore are caused by dissolution of buried salt layers and collapse of the surface into dissolution caverns. However, signs of piping and subsurface flows were observed in some sinkhole sites. In this paper, we show that robust identification of sinkhole origin can be achieved when proper geophysical methodologies and their application are used. We consider Newe Zohar site located in the southern part of the Dead Sea in order to analyse different signs of sinkhole formation models using various geophysical methods. The Seismic refraction method (SRFR), enables us to discover the salt layer based on longitudinal wave velocity Vp; the Multichannel Analysis of Surface Waves (MASW) method allows to determine the salt layer properties (rigidity) based on shear wave velocity Vs; finally, the Time Electromagnetic (TEM) method allows us to evaluate the degree of aggressiveness of groundwater with respect to salt, based on bulk resistivity values. Here we analyse competitive models of sinkhole formation and suggest geophysical methods to determine the subsurface geomorphology. We show that various geophysical methods should be applied in concert to explore the subsurface for the occurrence of salt, as well as understanding sinkhole formation processes. The underlying voids along the Dead Sea are shown to form primarily by salt dissolution, with some cases of additional piping. Applying the right geophysical parameters for groundwater and salt sediments classification proves to be crucial for understanding the subsurface geomorphology.

中文翻译：

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使用表面地球物理方法识别天坑起源，死海，以色列

摘要 在过去的 30 年中，死海西部和东部 (DS) 海岸遭受了强烈的天坑塌陷。最早的研究人员已经考虑了一个下沉洞形成的管道模型，该模型基于地下流动冲刷细粉。随后，大量钻孔和地震折射调查证明，西岸落水洞是由埋藏盐层溶解和地表塌陷形成溶洞造成的。然而，在一些天坑位置观察到管道和地下流动的迹象。在本文中，我们表明，当使用适当的地球物理方法及其应用时，可以实现对天坑起源的稳健识别。我们考虑位于死海南部的 Newe Zohar 站点，以便使用各种地球物理方法分析下沉洞形成模型的不同迹象。地震折射法 (SRFR)，使我们能够根据纵波速度 Vp 发现盐层；表面波多通道分析 (MASW) 方法允许根据剪切波速度 Vs 确定盐层特性（刚度）；最后，时间电磁 (TEM) 方法使我们能够根据体电阻率值评估地下水对盐的侵蚀程度。在这里，我们分析了天坑形成的竞争模型，并提出了确定地下地貌的地球物理方法。我们表明，应该协同应用各种地球物理方法来探索地下的盐分，以及了解下沉洞的形成过程。死海沿岸的底层空隙主要由盐溶解形成，在某些情况下还有额外的管道。为地下水和盐沉积物分类应用正确的地球物理参数被证明对于理解地下地貌至关重要。