Self-accelerated development of salt karst during flash floods along the Dead Sea Coast, Israel

Yoav Avni, Nadav Lensky, Elad Dente, Maayan Shviro, Reuma Arav, Ittai Gavrieli, Yoseph Yechieli, Meir Abelson, Hallel Lutzky, Sagi Filin, Itai Haviv, Gidon Baer

Research output: Contribution to journalArticlepeer-review

Abstract

We document and analyze the rapid development of a real-time karst system within the subsurface salt layers of the Ze'elim Fan, Dead Sea, Israel by a multidisciplinary study that combines interferometric synthetic aperture radar and light detection and ranging measurements, sinkhole mapping, time-lapse camera monitoring, groundwater level measurements and chemical and isotopic analyses of surface runoff and groundwater. The >1 m/yr drop of Dead Sea water level and the subsequent change in the adjacent groundwater system since the 1960s resulted in flushing of the coastal aquifer by fresh groundwater, subsurface salt dissolution, gradual land subsidence and formation of sinkholes. Since 2010 this process accelerated dramatically as flash floods at the Ze'elim Fan were drained by newly formed sinkholes. During and immediately after these flood events the dissolution rates of the subsurface salt layer increased dramatically, the overlying ground surface subsided, a large number of sinkholes developed over short time periods (hours to days), and salt-saturated water resurged downstream. Groundwater flow velocities increased by more than 2 orders of magnitudes compared to previously measured velocities along the Dead Sea. The process is self-accelerating as salt dissolution enhances subsidence and sinkhole formation, which in turn increase the ponding areas of flood water and generate additional draining conduits to the subsurface. The rapid terrain response is predominantly due to the highly soluble salt. It is enhanced by the shallow depth of the salt layer, the low competence of the newly exposed unconsolidated overburden and the moderate topographic gradients of the Ze'elim Fan.

Original languageEnglish
Pages (from-to)17-38
Number of pages22
JournalJournal of Geophysical Research: Earth Surface
Volume121
Issue number1
DOIs
StatePublished - 1 Jan 2016
Externally publishedYes

Bibliographical note

Publisher Copyright:
©2015. American Geophysical Union. All Rights Reserved.

Keywords

  • InSAR
  • flash floods
  • karst
  • lidar
  • sinkholes
  • subsidence

ASJC Scopus subject areas

  • Geophysics
  • Earth-Surface Processes

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