InSAR-based modeling and analysis of sinkholes along the Dead Sea coastline

Abstract

Sinkholes commonly form by subsurface dissolution cavities that collapse after the overlying layers become mechanically unsupported. Sinkholes along the Dead Sea shorelines are preceded by, associated with, and followed by gradual surface subsidence that accompanies the cavities' growth. We exploit satellite radar interferometry (interferometric synthetic aperture radar) to resolve temporal and spatial relationships between gradual subsidence and sinkhole collapse. The geometry of the deflating cavity roof is determined by elastic inverse modeling of the surface displacements. A Coulomb failure stress criterion is applied to calculate the stress field induced by the deflating cavity at the ground surface. We find that the induced stress field favors generation of sinkholes at the perimeters of the subsiding areas rather than at their centers, in agreement with field observations, providing important information for sinkhole hazard assessment. Further, our analysis suggests that short-term deformation in consolidated gravel layers at shallow depths could be approximated by simple elastic modeling. Key Points Dead Sea sinkhole precursors are detected by InSAR Sinkholes commonly appear at the perimeters of the subsiding areas Analytical elastic models may explain the sinkhole formation mechanism