Delayed subsidence of the Dead Sea shore due to hydro-meteorological changes

Sibylle Vey,J Wickert,J Vüllers,M Weber,P Teatini,D Al-Halbouni,G Dick,F Alshawaf,M Ramatschi,A Güntner,M Haghshenas Haghighi

doi:10.1038/s41598-021-91949-y

Abstract

Many studies show the sensitivity of our environment to manmade changes, especially the anthropogenic impact on atmospheric and hydrological processes. The effect on Solid Earth processes such as subsidence is less straightforward. Subsidence is usually slow and relates to the interplay of complex hydro-mechanical processes, thus making relations to atmospheric changes difficult to observe. In the Dead Sea (DS) region, however, climatic forcing is strong and over-use of fresh water is massive. An observation period of 3 years was thus sufficient to link the high evaporation (97 cm/year) and the subsequent drop of the Dead Sea lake level (− 110 cm/year), with high subsidence rates of the Earth’s surface (− 15 cm/year). Applying innovative Global Navigation Satellite System (GNSS) techniques, we are able to resolve this subsidence of the “Solid Earth” even on a monthly basis and show that it behaves synchronous to atmospheric and hydrological changes with a time lag of two months. We show that the amplitude and fluctuation period of ground deformation is related to poro-elastic hydro-mechanical soil response to lake level changes. This provides, to our knowledge, a first direct link between shore subsidence, lake-level drop and evaporation.

Highlights

MotivationThe Dead Sea is a hyper-saline terminal lake located in the Dead Sea transform rift system[1,2,3]
We show that the amplitude and fluctuation period of ground deformation is related to poroelastic hydro-mechanical soil response to lake level changes
Land subsidence at the Dead Sea region occurs on different spatial and temporal scales[7]: (1) Meter to decimeter scale sinkholes are related to subsurface material dissolution and mechanical mobilization[30,32] either due to dissolution of a salt e dge[56,57], structurally controlled groundwater percolation[58,59] or subsurface stream c hannels[36,60,61] Formation rates vary hereby from sudden or in the order of mm-cm/month as determined by photogrammetric/interferometric synthetic aperture radar (InSAR)/LiDAR studies[34,36,40,41,44] and morphologies of such sinkholes vary according to mechanical properties of the overburden[66,67]

Summary

Motivation

The Dead Sea is a hyper-saline terminal lake located in the Dead Sea transform rift system[1,2,3]. In high temporal resolution, evaporation and lake level changes at the Dead Sea and are able to determine a first direct and interdisciplinary link on a monthly basis between the Solid Earth, climate and water processes. To validate the GNSS reflectometry method, we compare the GNSS derived DS lake level with gauge measurements near Massada (31.32863 N, 35.40299 E) from the Hydrological Service and Water Authority in Israel, for the 3-year observation period (Fig. 2). The sum of evaporation losses and of water withdrawals for the potash production, which amount to close to half of the evaporation losses, cannot be compensated by the surface and subsurface inflow to the DS and cause the long-term decline of its water t able[3]

Findings

Discussion

Summary