Sinkhole precursors along the Dead Sea, Israel, revealed by SAR interferometry

Abstract

The water level in the Dead Sea (Israel and Jordan) has been dropping at an increasing rate since the 1960s, exceeding one meter per year during the last decade. This drop has triggered the formation of sinkholes and widespread land subsidence along the Dead Sea shoreline, resulting in severe economic loss and infrastructural damage. In this study, the spatiotemporal evolution of sinkhole-related subsidence and the effect of human activities and land perturbation on sinkhole development are examined through interferometric synthetic aperture radar measurements and fi eld surveys conducted in Israel during 2012. Interferograms are generated using COSMO-SkyMed satellite images and a high-resolution (0.5 m/pixel) elevation model obtained from LiDAR measurements. As a result of this unique combination of high-resolution data sets, millimeter-scale subsidence has been resolved in both natural and human-disturbed environments. Precursory subsidence over a period of a few months occurred before the collapse of all three sinkhole sites reported in this study. The centers of the subsiding areas migrated, possibly due to progressive dissolution and widening of the underlying cavities. Filling of newly formed sinkholes with gravel, and mud injections into drill holes, seem to enhance land subsidence, enlarge existing sinkholes, and form new sinkholes. Apart from shedding light on the mechanical process, the results of this study may pave the way for the implementation of an operational sinkhole early-warning system.

A 3D Numerical Approach to Assess the Temporal Evolution of Settlement Damage to Buildings on Cavities Subject to Weathering

“…The reliability of the ties, the subsidence basin in the 3D analysis assumes a circular shape, which is typical for the sinkholes observed in these rocks (Parise and Lollino 2011). As recently observed by Nof et al (2013) and Jones and Blom (2014) with interferometric synthetic aperture radar (inSAR), subsidence basins can be used a precursory signs of sinkhole formation. Interestingly, also the 3D FEM simulation presented here captures this feature.…”

“…Despite the fact that final stages of sinkhole formation in soft rocks is usually characterized by a rapid brittle type of global failure (Lollino and Andriani 2017), recent interferometric synthetic aperture radar (inSAR) measurements show that ground movements start to accumulate with time several months before the collapse (Chang and Hanssen 2014;Intrieri et al 2015;Jones and Blom 2014;Nof et al 2013). In the Marsala Panatletico 2011 sinkhole, signs of instability, such as open fractures and detachment blocks, were observed already 1 year prior to collapse (Fazio et al 2017).…”

Characterization of Black Sand Mining Activities and Their Environmental Impacts in the Philippines Using Remote Sensing

“…This larger extent of the subsiding areas likely reflects groundwater usage or sediment redistribution around the affected areas. We also notice that the spatial extent of the subsiding areas associated with the black sand mining sites is small compared to the extent of the land subsidence associated with other processes such as ground water extraction, e.g., [13][14][15]; oxidation of peatlands, e.g., [31]; natural sediment compaction e.g., [32]; slope motion e.g., [33]; sinkholes e.g., [34]; and hydrothermal or magmatic activity, e.g., [12,35]. Thus, the small spatial extent of the land subsidence associated with black sand mining activities can be used to detect black sand mining sites and isolate this process from others.…”

DInSAR-Based Detection of Land Subsidence and Correlation with Groundwater Depletion in Konya Plain, Turkey

“…Our analysis provides 17-21 measure points/km 2 and the extent of the largest "young" obruk (<500 m 2 ) is also below the mentioned minimum detectable dimensions. Nof et al [63] demonstrate that small sinkhole induced deformation or collapse precursory displacements can be recognized with DInSAR techniques using high resolution data such as the SAR images provided by the COSMO-SkyMed satellite (pixel size of 3 m). Moreover, a higher spatial resolution is needed for recognizing sinkhole collapse precursory displacements.…”