July 9, 2019

Yingqing Qiu (OSU) M9 Seminar on Behavior of Coastal Sediments During Tsunamis

We are delighted to host Yingqing Qiu, PhD candidate in the School of Civil and Construction Engineering at Oregon State University at our upcoming All Hands meeting. She is working on earthquake rupture models and then propagating tsunami generation, to investigate sediment instability on the shoreline. We will be meeting in ATG 154 on July 9th from 2:30-3:30.TG 154 on July 9th from 2:30-3:30.

Abstract

The talk will focus on numerical analysis and corresponding uncertainty quantification methods for examining coastal sediment behavior during an earthquake-tsunami multi-hazard. The finite element framework OpenSees was used to build the soil model, and Biot’s poroelasticity equations were solved to couple the solid displacement and pore water pressure. SCHISM is used to generate tsunami wave height-times series along the pacific northwest coastline by inputting the seabed displacement. Based on paleoseismic estimates of coastal subsidence, both uniform slip and heterogeneous slip distribution along the megathrust are considered to generate seabed deformation using the Okada dislocation model. Some numerical experiments with reasonable earthquake motions are presented, and the results are discussed in terms of sediment transport potential. The sensitivity of the model results to hydraulic conductivity is also examined using a stochastic finite element solver. The talk ends with a discussion of an inverse solution to find reasonable hydraulic conductivity distributions in seabeds.