Document Type
Thesis
Date of Degree Completion
Spring 2016
Degree Name
Master of Science (MS)
Department
Geological Sciences
Committee Chair
Anne Egger
Second Committee Member
Walter Szeliga
Third Committee Member
Lisa Ely
Abstract
Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± 0.02 mm/yr in the northern section, 1.07 ± 0.10 mm/yr in the central section, and 0.36 ± 0.04 mm/yr in the southern lake section. Potential field modeling of profiles drawn through detailed, gridded gravity and magnetic data, suggest that the surficial scarps continue at depth, where they may accommodate greater offset. These results refine the time-averaged slip rate along the SVF and show variability spatially and temporally, allowing for correlations with changes in paleolake levels. This study suggest iv complex relation between pluvial lakes and their proximal faults that show that the lake likely influenced earthquake recurrence and slip rate along the SVF.
Recommended Citation
Marion, Brian N., "Spatiotemporal Slip Rate Variations Along Surprise Valley Fault in Relation to Pleistocene Pluvial Lakes" (2016). All Master's Theses. 374.
https://digitalcommons.cwu.edu/etd/374
Appendix A - Plate 1 - Surprise Valley with mapped paleoshorelines
Language
English
Included in
Geochemistry Commons, Geology Commons, Geomorphology Commons, Geophysics and Seismology Commons, Tectonics and Structure Commons