This award will support a long-term visit by Professor Robert Yeats, Department of Geosciences, Oregon State University, to Japan for a cooperative research project with Dr. Yoshi Kinugaso of the Seismotectonic Research Division at the Geological Survey of Japan in Tsukuba. The Research will include a study of the recognition and evaluation of seismogenic blind thrusts. Earthquakes that occur in fold belts can be studied using surface geology and subsurface well logs and seismic lines, particularly those that occur in petroleum-producing regions. A better understanding of the tie between folds, faults and seismegenesis in recent years is partly the result of a growing awareness of the extreme hazards posed by fault propagation fold systems in highly populated regions of California. Research will include a study of the structural aspects of earthquake faults that do not cut the surface but instead appear to be accommodated by regional-scale folding. Results of the research have the potential of broadening U.S. databases on seismogenic zones expressed at the surface as folds. Additionally, the research could lead to the possibility of constraining earthquake size by considering the possibility of fault and fold segmentation as well as slip rate. The Geological Survey of Japan is well known for their ongoing research in the area of evaluating seismic risks from surface faulting. Their expertise, coupled with Professor Yeats' expertise in the area of seismic risks from blind faults, should provide a fruitful collaboration. It is expected that this collaborative effort will continue after the formal agreement has terminated.
