Analysis and selection of magnitude relations for the Working Group on Utah Earthquake Probabilities
Prior to calculating time-independent and -dependent earthquake probabilities for faults in the Wasatch Front region, the Working Group on Utah Earthquake Probabilities (WGUEP) updated a seismic-source model for the region (Wong and others, 2014) and evaluated 19 historical regressions on earthquake magnitude (M). These regressions relate M to fault parameters for historical surface-faulting earthquakes, including linear fault length (e.g., surface-rupture length [SRL] or segment length), average displacement, maximum displacement, rupture area, seismic moment (Mo ), and slip rate. These regressions show that significant epistemic uncertainties complicate the determination of characteristic magnitude for fault sources in the Basin and Range Province (BRP). For example, we found that M estimates (as a function of SRL) span about 0.3–0.4 units (figure 1) owing to differences in the fault parameter used; age, quality, and size of historical earthquake databases; and fault type and region considered.
Citation Information
Publication Year | 2015 |
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Title | Analysis and selection of magnitude relations for the Working Group on Utah Earthquake Probabilities |
Authors | Christopher DuRoss, Susan Olig, David Schwartz |
Publication Type | Conference Paper |
Publication Subtype | Conference Paper |
Index ID | 70189826 |
Record Source | USGS Publications Warehouse |
USGS Organization | Geologic Hazards Science Center |