Dynamics of a Giant Slow Landslide Along the Coast of the Aral Sea (Central Asia)

Abstract

This paper presents the dynamics of the world's largest lateral mega-spreading landslide cluster along the western shoreline of the Aral Sea in Uzbekistan (Central Asia) using Interferometric Synthetic Aperture Radar (InSAR) time series analysis of three Sentinel-1 IW datasets over the period 2015–2020. It extends >50km wide and corresponds to a gravity-induced lateral spreading movement of relatively intact Sarmatian limestone blocks that are sliding over a highly plastic clay layer at rates up to 40 mm/yr with a clear dominance of horizontal motion at a nearly constant velocity. Slow vertical motions (up to 5 mm/yr) are localized along narrow strips of terraces where rock spread is attributed to rotational subsidence.