Abstract
Abstract. Enclosed topographic depressions are characteristic of karst landscapes on Earth. The developmental relationship between depression types, such as sinkholes (dolines) and uvalas, has been the subject of debate, mainly because the long developmental timescales in classical limestone karst settings impede direct observation. Here we characterize the morphometric properties and spatio-temporal development of ∼1150 sinkholes and five uvalas formed from ∼1980 to 2017 in an evaporite karst setting along the eastern coast of the hypersaline Dead Sea (at Ghor Al-Haditha, Jordan). The development of sinkhole populations and individual uvalas is intertwined in terms of onset, evolution and cessation. The sinkholes commonly develop in clusters, within which they may coalesce to form compound or nested sinkholes. In general, however, the uvalas are not defined by coalescence of sinkholes. Although each uvala usually encloses several clusters of sinkholes, it develops as a larger-scale, gentler and structurally distinct depression. The location of new sinkholes and uvalas shows a marked shoreline-parallel migration with time, followed by a marked shoreline-perpendicular (i.e. seaward) growth with time. These observations are consistent with theoretical predictions of karstification controlled by a laterally migrating interface between saturated and undersaturated groundwater, as induced by the 35 m fall in the Dead Sea water level since 1967. More generally, our observations indicate that uvalas and the sinkhole populations within them, although morphometrically distinct, can develop near-synchronously by subsidence in response to subsurface erosion.
Highlights
Sinkholes and uvalas are types of enclosed topographic depressions and they are characteristic of karst regions on Earth
We characterize the morphometric properties and spatio-temporal development of ∼ 1150 sinkholes and five uvalas formed from ∼ 1980 to 2017 in an evaporite karst setting along the eastern coast of the hypersaline Dead Sea
The pre-recession bathymetry was steepest in the northern part of the study area (Fig. 3a), reflecting its proximity to the escarpment of the Eastern Boundary Fault of the Dead Sea basin (Fig. 1a, c)
Summary
Sinkholes and uvalas are types of enclosed topographic depressions and they are characteristic of karst regions on Earth. In such regions, which make up ∼ 15 % of the Earth’s dry land surface (BGR et al, 2017; Chen et al, 2017), the bedrock or surficial material is composed of carbonate, sulfate or halide minerals that are prone to dissolution by water. Sinkholes ( termed dolines) and uvalas are distinct with regard to scale, morphometry and their inter-relationship (Calic, 2011). Watson et al.: Sinkholes and uvalas in evaporite karst size and typically in the range of 10–200 m (Bondesan et al, 1992).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have