Geomorphological response of the Lower Jordan River basin to active tectonics of the Dead Sea Transform

摘要

The Lower Jordan River (LJR) basin has been shaped on an active tectonic segment of the Dead Sea Transform (DST), the Jordan Valley Fault (JVF), which remains relatively unexplored due to its rough terrain conditions, hyper-arid climate, and location along a political border where minefields are common. The ability to detect the morphology of the valley surface by remote sensing methods provides an opportunity to follow the complex tectonic structure of the LJR basin, and the spatial and temporal geomorphic processes that have shaped the basin since its exposure in the early Holocene after the desiccation of Lake Lisan (~14.5 ky BP). In this study, we use GIS analyses and image processing to explore the relation between the geomorphology of the LJR basin and the active tectonics of the JVF. The morphometric fluvial parameters of the basin are interpreted in relation to mapped faults, geophysical gravity interpolation, and seismic data. We introduce morphometric-gravity relations that show an increasing trend of the morphometric parameters' standard deviation (STD) as a function of the gravity anomaly increase, which are consistent with stream power formulation studies and seismic measurements. Our results show that the active tectonics of the JVF is concentrated towards the basin's center and the Dead Sea Fault location, and that at the borders of the gravity highs, sinuosity, slope and width changes, together with recent seismic activity, all suggest on tectonic uplifting and active faulting in those areas.