Project II.4.3: Coastal subsidence

Project Title: II.4.3 Coastal subsidence
Project Lead: Modeling Team

Project Description
A major seismic event on the Cascadia Subduction-Zone, such as occurs on average about every 300-350 years, is expected to produce a vertical drop in the shelf of about 2 meters near the mouth of the Columbia. This project alters the standard river-to-shelf domain grid to reflect such a subsidence event, and evaluates the resultant simulation to identify the impacts of the drop on Columbia River estuary and plume processes.

Fit in program
This scenario places the CMOP’s grand challenges in context, as coastal subsidence might, for PNW, have impacts of the order of magnitude or larger than climate change and anthropogenic activity.

Outcomes
The impacts of subsidence were integrated into the simulation run, using db14 weeks 16 through 36 of 2004 as a baseline. Several aspects of this scenario have been evaluated, including the physical characteristics of the plume, the maximum distances of salinity intrusion, and the relative availability of juvenile salmonid habitat (as defined by velocity, depth, temperature, and salinity).

Last updated May 2009