קולוקוויום בחוג לגאופיזיקה: Sediment Transport Across Fluvial, Coastal, and Shelf Environments: From Field Observations to Grain-Scale Simulations

Zoom: https://tau-ac-il.zoom.us/j/85032703038

Abstract:

In this seminar, I investigate sediment transport and deposition across fluvial, coastal, nearshore, and shelf environments, where sediment motion is a fundamental driver of landscape and seascape evolution under changing climate conditions. Predicting sediment transport remains challenging because it emerges from fluid–sediment interactions that span scales from individual grains to entire landscapes and operate across diverse hydrodynamic environments. In the first part of the talk, I use the rapidly regressing shores of the Dead Sea as a natural laboratory to examine the evolution of newly emerged landscapes. I show how channels incise across the exposed shelf, increasing fluvial sediment flux to the lake, and how waves and currents subsequently redistribute and sort coarse and fine sediments along the coast and within the nearshore zone. I then explore how regional synoptic-scale atmospheric circulation links these fluvial and coastal sediment conveyors and shapes the resulting coastal sedimentary architecture. These processes are investigated through high-resolution field observations and innovative monitoring approaches, including smart instrumented boulders. In the second part of the seminar, I focus on internal waves interacting with mobile sediment slopes using particle-resolved direct numerical simulations. By resolving both the flow field and individual sediment grains, these simulations provide quantitative and mechanistic insights into erosion, deposition, sediment redistribution, and slope stability beneath internal waves—an important yet poorly understood process in stratified lakes, seas, and continental margins worldwide. Together, these studies contribute to a broader research vision aimed at establishing mechanistic links between grain-scale sediment dynamics and landscape-scale geomorphic evolution across diverse hydrodynamic environments.

מארגן האירוע: ד"ר ליאור רובננקו