Physical Sciences and Mathematics Commons^™

Late Holocene Tsunami Deposits At Salt Creek, Washington, Usa, Ian Hutchinson, Curt D. Peterson, Sarah L. Sterling

Anthropology Faculty Publications and Presentations

We interpret two thin sand layers in the estuarine marsh at Salt Creek, on the southern shore of the Strait of Juan de Fuca, as the products of tsunamis propagated by earthquakes at the Cascadia subduction zone. The sand layers extend for about 60 m along the left bank of the creek about 800 m from the mouth, and can be traced to the base of a nearby upland area. One layer is exposed in the creek bank about 400 m further upstream, but they are only patchily distributed in the rest of the central area of the marsh. Both …

Accommodation Space Controls On The Latest Pleistocene And Holocene (16–0 Ka) Sediment Size And Bypassing In The Lower Columbia River Valley: A Large Fluvial–Tidal System In Oregon And Washington, Usa, Curt D. Peterson

Geology Faculty Publications and Presentations

In this study, we establish the roles that increasing basin accommodation space have on sediment size and bypassing in the transgressive fill (16–0 ka) in the submerged Lower Columbia River Valley (LCRV). The antecedent forearc valley (225 km in length, 4–8 km in width, and 60–115 m in axial valley depth) is characterized by high sediment supply rates (10–15 million t y-1) but no delta at its mouth to the Pacific Ocean. Core sample sediment textures (N ¼ 1600) are analyzed from 3000 m of borehole sections in 58 representative boreholes to characterize the ancestral valley fill: 57% sand, 17% …

Landslide Velocity, Thickness, And Rheology From Remote Sensing; La Clapiere Landslide, France, Adam M. Booth, Michael P. Lamb, Jean-Philippe Avouac, Christophe Delacourt

Geology Faculty Publications and Presentations

Quantifying the velocity, volume, and rheology of deep, slow-moving landslides is essential for hazard prediction and understanding landscape evolution, but existing field-based methods are difficult or impossible to implement at remote sites. Here we present a novel and widely applicable method for constraining landslide 3-D deformation and thickness by inverting surface change data from repeat stereo imagery. Our analysis of La Clapiere, an approximately 1 km (super 2) bedrock landslide, reveals a concave-up failure surface with considerable roughness over length scales of tens of meters. Calibrating the thickness model with independent, local thickness measurements, we find a maximum thickness of …

Predicting Landslides In Real Time, Michael J. Olsen

TREC Project Briefs

The Oregon Department of Transportation, or ODOT, has an ongoing struggle to maintain public highways against earth movements such as erosion, earthquakes and landslides. An earthquake or landslide can close down a road for days, while highway workers fight to keep supply lines open and repair the damage. Particularly along Oregon’s coastal roads with high sea cliffs, these natural processes are a constant threat to transportation infrastructure. The damage caused by gradual erosion is typically not detectable until there is a landslide or other disaster, costing the state considerable time and money to repair. New technology has the potential to …

Appendix C—Deformation Models For Ucerf3, Tom Parsons, Kaj M. Johnson, Peter Bird, Jayne Bormann, Timothy E. Dawson, Edward H. Field, William C. Hammond, Thomas A. Herring, Robert Mccaffrey, Zheng-Kang Shen, Wayne R. Thatcher, Ray J. Weldon Ii, Yuehua Zeng

Geology Faculty Publications and Presentations

This document describes efforts to best characterize seismogenic deformation in and near California. The rate of hazardous earthquakes in California is expected to be proportional to deformation rates; in particular, the rates at which faults slip. Fault slip rates are determined from offsets of geologic and geomorphic features of measured age and by modeling geodetically determined surface displacement rates. Extensive use of geodesy in the form of Global Positioning System (GPS) observations is a new feature brought into the Working Group on California Earthquake Probabilities (WGCEP) forecasts for the Uniform California Earthquake Rupture Forecast, version 3 (UCERF3) model. Geodetic measurements …

Strain Energy Release From The 2011 9.0 Mw Tōhoku Earthquake, Japan, Kenneth M. Cruikshank, Curt D. Peterson

Geology Faculty Publications and Presentations

The purpose of this paper is to compare the strain energy released due to elastic rebound of the crust from the tragic 2011 9.0 Mw Tōhoku earthquake in Japan with the observed radiated seismic energy. The strain energy was calculated by analyzing coseismic displacements of 1024 GPS stations of the Japanese GEONET network. The value of energy released from the analysis is 1.75 × 1017 J, which is of the same order of magnitude as the USGS-observed radiated seismic energy of 1.9 × 1017 Nm (J). The strain energy method is independent of seismic methods for determining the energy released …

Impacts Of Predicted Global Sea-Level Rise On Oregon Beaches And Tidelands, Curt D. Peterson

Geology Faculty Publications and Presentations

Forward by:

Phillip Johnson, Executive Director Oregon Shores Conservation Coalition

The Oregon Shores Conservation Coalition’s "Coastal Climate Change Adaptation Project" is under development as an experiment in grassroots organizing for adaptive planning for expected climate change impacts. Oregon Shores is a regional conservation group with a 40-year history of working to protect marine, shoreline, estuarine and other coastal habitats. The organization’s board and staff came to recognize that the likely effects of climate change—rising sea levels, more intensive storm surges, increased erosion, lower-river flooding, among others—would affect every aspect of the group’s work. Consequently, a new program, the Climate Action …

Topographic Signatures And A General Transport Law For Deep-Seated Landslides In A Landscape Evolution Model, Adam M. Booth, Joshua J. Roering, Alan W. Rempel

Geology Faculty Publications and Presentations

A fundamental goal of studying earth surface processes is to disentangle the complex web of interactions among baselevel, tectonics, climate, and rock properties that generate characteristic landforms. Mechanistic geomorphic transport laws can quantitatively address this goal, but no widely accepted law for landslides exists. Here we propose a transport law for deep-seated landslides in weathered bedrock and demonstrate its utility using a two-dimensional numerical landscape evolution model informed by study areas in the Waipaoa catchment, New Zealand, and the Eel River catchment, California. We define a non-dimensional landslide number, which is the ratio of the horizontal landslide flux to the …