Speaker: Meagan Wengrove, Assistant Professor of Coastal Engineering, School of Civil and Construction Engineering, College of Engineering, Oregon State University

Topic:  Beach Dune Subsurface Hydrodynamis and the Formation of Dune Scarps

We carried out a 1:2.5 scale beach dune erosion experiment to study the subsurface hydrodynamics involved in scarp formation. Measurements of the subsurface hydrodynamics and external forcing of the prototype dune were collected in the NSF NHERI O.H. Hinsdale Wave Research Laboratory Large Wave Flume at Oregon State University. Pressure and moisture sensors buried within the dune tracked the location of the water table over the course of the experiment and captured the influence of wave runup events on pore water pressure and moisture content within the dune. A line-scan lidar was used to determine the runup elevation of each bore and to track erosion along a single cross-shore transect throughout the experiment. We observed that wave driven accretion caused by runup events greater than R2% adjacent to beach/dune erosion caused by partial momentary liquefaction events (due to runup greater than R16%) create an slope instability that is the initial discontinuity leading to scarp formation. Following, scarp landward progression ensues due to collision and slumping. 

Link:

https://oregonstate.zoom.us/j/94555731151?pwd=RnJ6eVg0ODdzRUpVc0pQbUlIdUV3dz09

Password: 972587 or call +1-971-247-1195 US Meeting ID: 945 5573 1151