一、时间：2025年10月22日（周三）9:00

二、地点：舟山校区教学楼132

三、主讲人：英国阿伯丁大学 Benjamin Kneller教授

四、报告题目：Particulate density currents in Nature: a reality check

报告摘要：

Natural particulate gravity currents include a very wide range of phenomena, from haboobs (dust storms), snow avalanches and pyroclastic flows, through low and high-density turbidity currents to granular flows and submarine landslides. Most gravity currents are density-stratified. They may be either continuously stratified (‘supercritical’), as a result of the balance between particle settling and turbulent diffusion, or bipartite (‘subcritical’). The first problem this creates is how one defines Froude criticality, which should refer to the speed of internal waves. High density flows may also be bipartite, with high-density basal (usually frontal) cell with particle concentrations that may be well in excess of ten percent by volume, in which particle interactions become significant, and a sharp interface with a low-density cloud above. Density stratification is critical to entrainment (or lack thereof), which controls the propagation distance. Interstitial fluid that is buoyant with respect to the ambient (in hyperpycnal flows and pyroclastic flows) leads to detrainment of interstitial fluid, and ultimately to reversing buoyancy. Gravity currents often flow into stratified ambient and may become intrusions, such as volcanic plumes and nepheloid layers. They are often subject to ambient currents, as in volcanic plumes, river plumes such as the Amazon, turbidity currents and tides in submarine canyons and trenches, and deep oceanic currents as in the South China Sea canyons. And on scales exceeding the Rossby radius they are subject to the effects of the Earth’s rotation, as seen in the asymmetry of submarine channel levees.

主讲人简介：

Benjamin Kneller，英国阿伯丁大学教授，在海洋沉积学领域深耕近30年，是世界著名的海洋沉积学家，同时是美国石油地质学家协会(American Association of Petroleum Geologists)、伦敦地质学会(Geological Society of London)、美国地球物理联合会(American Geophysical Union)三个协会的会士。在深海沉积体系和重力流沉积过程研究方面成果卓著，近年来已在国际重要期刊上发表了近百篇文章，其文章总引用次数超过3000次，H-index高达30左右，在海洋浊流沉积学领域产生了重要影响。曾在谢菲尔德大学、利兹大学、加州大学圣巴巴拉分校及阿伯丁大学等国际高校执教本科课程，并在成都科技大学讲授海洋沉积学（英语授课）。同时，为多家石油天然气公司定制并讲授专业商业课程。