I study mechanical weathering processes and landscape evolution in the cold dry environments of Antarctica’s polar deserts and Mars. The project focuses on the McMurdo dry valleys in Antarctica and the overlooked role of hygroscopic salts in accelerating mechanical weathering. I combine topographic and remote sensing data analysis with numerical modeling to constrain the processes that drive rock cracking and the development of prominent topographic asymmetry in U-shaped valleys. The project involved scientists from The Geological Survey of Israel, US Universities (UNC Charlotte, University of Washington), and NASA.

Mountain permafrost is extremely sensitive to climate change and its degradation is supposedly responsible for the recent increase in periglacial rock slope failures in high mountains. I study the mechanical and thermal processes related to water infiltration in rock fractures. I use numerical modeling to simulate the energy balance between the rock surface and atmosphere to estimate the rock temperature and the amount of water that is available for infiltration. These simulations are used as input in a finite elements model (COMSOL Multiphysics), on a high-performance computer, to simulate hydrological and thermal processes in fractured rock. 

To support the model simulations, I collect data from high elevation field sites in the French Alps, including estimations of snow cover dynamics using time-lapse camera images processing, snow depth change detection using 3D models from repeated drone-based surveys, temperatures measurements from rock surface sensors and in boreholes, and more.  

The research on forest fires is gaining much attention in the last decade due to the increased occurrence of large forest fires in Australia and western USA, and also Israel. In this project I study the influence of forest fires on hillslope processes such as rock weathering using a numerical thermos-mechanical model, and soil transport and debris flow.

In this project, I am leading a novel experimental system that monitor and collect snowmelt water directly from fractures that intersect artificial tunnels carved in a cable car station in a field site, at 3800 m above sea level, in the Mont-Blanc range in the French Alps. The information from this system includes temperature, resistivity, and fluorescence dye that I inject in the snow above, and gives new vital information on the timing and dynamics of poorly understood hydrogeological processes in mountain permafrost. 

Topographic asymmetry is a natural phenomenon where either polar- or equatorial-facing hillslopes are systematically steeper than the opposite. It is commonly observed in many environments and in both weathering- and transport-limited conditions. Using high resolution topography (LiDAR) and satellite-based remote sensing we can compare various topographic indices with information about vegetation cover, temperature, and moisture to decipher possible mechanisms for the development of asymmetry. Further analysis of transport rate and soil production is possible using geochemical analysis of samples from opposite-facing hillslopes, and landscape evolution models. The figure below is from a paper about the evolution of topographic asymmetry in volcanic cinder cones the Golan Heights (Ben-Asher et al; 2017).

I study carbonate hillslopes along a climatic gradient from the dry Negev Desert to the Mediterranean Galilee. I use high-resolution topography (from airborne LiDAR) to quantify topographic parameters. I developed several tools and filters for flow routing and catchment hydrology, landform characterization and topographic indices. 

I proposed a new modified model of hillslope evolution that incorporates two factors that are often neglected: dust and chemical weathering. I sampled soil, bedrock and dust and used geochemical tools to quantify fluxes of dust, soil production and erosion. By combining the results, I gained new insights on the evolution of carbonate hillslopes and the influence of various factors such as climate, vegetation, chemical weathering, bedrock strength, dust input and more.