Charles C.S. Song Fellowship Award Ceremony with Distinguished Lecture by Prof. Michael Lamb
Join us on Tuesday, March 28th at 3pm for a celebration of the 2023 Charles C.S. Song Fellowship recipient Shih-Hsun Huang, with a distinguished lecture by Prof. Michael Lamb.
Michael Lamb, Professor in the Division of Geological and Planetary Sciences at the California Institute of Technology
Distinguished lecture: Mud flocculation and the global sediment cycle
Abstract: River sediment loads are dominated by mud, which builds lowland landscapes and buries large amounts of organic carbon. While mechanistic theories exist for transport of suspended sand, mud in rivers is often thought to constitute washload—sediment with settling rates so slow that it does not interact with the land surface. The washload hypothesis, however, is seemingly at odds with the muddy terrain that abounds globally. Here I summarize recent work by our group to show that mud in many rivers is flocculated with settling velocities much larger than expected for individual particles, which allows it to interact with and deposit on the land. Our results help to explain why muddy landscapes exist today, why they were less abundant earlier in Earth history, and why anthropogenic disruption of the global sediment cycle is causing major unintended land loss.
About: Michael Lamb is a professor in the Division of Geological and Planetary Sciences at Caltech. Lamb’s research combines theory, field observations and flume experiments to understand landscape form and dynamics through the mechanics of erosion, sediment transport and deposition. Current projects include riverbank erosion in permafrost, coastal land building at river deltas, and ancient rivers on Mars. He received his PhD from U.C. Berkeley in Earth and Planetary Science, M.S. in Oceanography from the University of Washington, and B.S. in Geology and Geophysics from the University of Minnesota. He got his start at SAFL as a “junior scientist” from 2000-2001, conducting experiments on turbidity currents in the Garcia Flume, with the help of Gary Parker, Jeff Marr, Chris Paola, Tom Hickson, Chris Ellis and others. His grandfather worked somewhat successfully with Lorenz G. Straub.
2023 Charles C.S. Song Fellowship recipient Shih-Hsun Huang, advised by Prof. Judy Yang
Presentation title: Experimental investigations of hyporheic flow in channels with vegetation and large woody debris
Abstract: In-channel aquatic vegetation and large woody debris exert drag on the surface flow and create the heterogeneity of a hydraulic head along the stream bed, which drives a bi-direction flow through the sediment-water interface, or hyporheic flow. Hyporheic flow increases the retention time of solutes, organic matter, and fine particles, which controls the biogeochemical cycles of the benthic habitats and determines the retention and degradation of contaminants in the stream. While aquatic vegetation and large woody debris have been recognized to induce hyporheic flow in recent field and numerical studies, visualization and systematic quantification of hyporheic flow induced by aquatic vegetation and large woody debris remain lacking due to the opaqueness of sediment, vegetation, and woods. I will describe how we developed a refractive index match-based method to quantify the impact of vegetation and large woody debris on hyporheic flow in a laboratory flume.
About: Shih-Hsun Huang is a PhD candidate in civil engineering at the St. Anthony Falls Laboratory, studying under Professor Judy Yang. His research is focused on the mass transport across the sediment‐water interface in an aquatic environment. He currently studies the impact of in-channel vegetation and large wood debris on the hyporheic flow. Shih-Hsun received his master's degree in civil engineering from National Taiwan University in 2018. He also completed his bachelor's degree in both civil engineering and life science from National Taiwan University in 2016.