Active Tectonics & Seafloor Mapping Lab
Oregon State University
Volume 1
Number 1
Upcoming mapping cruises
While proposals to begin mapping the entire Territorial Sea gather momentum, other efforts to make some progress in 2008 are underway. Dr. Sam Johnson, Branch Chief of the USGS Western Coastal and Marine Team expects to conduct a ~ 10 day cruise in Oregon during the summer weather season. The Survey no longer has a large vessel, but has recently acquired a 34 ft. trailerable survey vessel, the Parke D. Snavely, equipped with a SwathPlus bathymetric sidescan sonar. This pilot effort will collaborate with OSU and the Seafloor Mapping Lab to map a target yet to be determined in the Oregon Territorial Sea. This collaborative work continues similar mapping USGS is conducting as part of the California Territorial Sea mapping effort that has been under way for the last several years.
The first cruise of the 2008 season will involve Steve Rumrill, Research Coordinator for the South Slough National Estuarine Research Reserve. Steve has been awarded ship time on the NOAA vessel MacArthur II in late April. Steve has agreed to devote much of the shiptime to seafloor mapping and will be collaborating with OSU for the acquisition and interpretation of the data, which will be collected at a site in Southern Oregon.
DOGAMI/OSU Tsunami Inundation Study
Tsunami inundation lines in the State are currently being updated; a multiyear process that hasn’t been done statewide since 1995. In the intervening years, much has been learned about the history of great earthquakes and past tsunamis along the Cascadia subduction margin which includes Oregon. In 2006, a pilot project was begun with funding from the National Tsunami Hazard Mitigation Program. These funds allow the states to implement locally determined priorities for tsunami hazard mitigation. George Priest of DOGAMI assembled a team to create the “Next Generation” tsunami inundation lines or the State at the initial pilot site at Cannon Beach. Everything in science is evolutionary, and the Cannon Beach study was designed to learn from some of the simplifications that were done to produce an earlier inundation map for Seaside in a NOAA/USGS project. Primarily, the Cannon Beach study set out to construct realistic geologic sources for earthquakes based on geodetic, geologic, and geophysical evidence of plate “locking” along the margin, something not previously done. Part of this project included new mapping of a major offshore “splay” fault and mapping of rupture extents of past earthquakes at OSU (Goldfinger) as well as mapping of onshore tsunami deposits at Canon Beach by Rob Witter of DOGAMI. The project included hydrodynamic modeling of the tsunami by Joseph Zhang and Antonio Baptista at OHSU, as well as deformation modeling by Kelin Wang of Pacific Geoscience Centre, Geologic Survey of Canada. The mapping part of the project also included stitching together onshore and offshore DEM’s, and modeling the tsunami with and without the dunes at Cannon Beach, as well as determining paleo sea level at the times of past earthquakes. The project will move next to the Bandon area where a second project will be done in 2008.
Also underway at OSU, the Hinsdale Wave Lab under the direction of Dan Cox recently constructed a physical model of Seaside Oregon and nearshore bathymetry to conduct inundation studies and code validation for numerical tsunami models done by Patrick Lynette of Texas A&M. The model runs were shown to a contingent of legislators and planners from coastal communities. Harry Yeh of OSU Engineering demonstrated his human response model to a Cascadia tsunami for Seaside. Model runs were also filmed by the Discovery Channel’s “Really Big Things” series (airing Feb. 8, 9, and 10) and by a Canadian Broadcasting Corp. documentary crew led by Jerry Thompson of Raincoast Productions that is putting together a comprehensive Cascadia tsunami story for 2008. The documentary includes high resolution “fly-throughs” of the Oregon margin bathymetry and earthquake animations created at OSU.
Shoreline Change Mapping
A group of investigators from DOGAMI, OSU, UW, Washington Department of Ecology and the South Slough Reserve are working on several study sites to evaluate coastal erosion. This involves beach profiling and mapping, and nearshore bathymetric sounding with a Jet Ski. This effort is under the NaNOOS Regional Coastal Ocean Observing System. DOGAMI will continue to conduct related LIDAR surveys along the Oregon coast to establish a high resolution coastal topographic baseline for coastal erosion studies.
See: Study objectives and 02/14/07 Press release, and Oregon LIDAR Consortium.