The GR hypothesis states that each fault section nucleates a GR distribution of earthquakes, with a of 1.0 and a maximum magnitude defined by the largest rupture in b-value which the section participates, including multi-fault ruptures. The rate of events, or the GR value, for each fault section can then be found by satisfying the section moment rate. Even before any inversion, we can sum all the consequent fault-section MFDs to obtain a total on-fault MFD. Two examples are shown in Figure 16. The red curve, which represents the Deformation model paired with the magnitude-area Relationship, exceeds ABM Shaw09mod not only the on-fault target (orange) but also the total regional target (black). The magenta curve, which represents the Deformation Model pared with the magnitude-area Zeng HanksBakun08 relationship, is just below the total target, and well above the on-fault target. Results for all other GR branches fall between these two cases. This discrepancy can be quantified as an on-fault coupling coefficient, defined as the ratio of the total rate of the target on-fault MFD (orange in Figure 16) to the total rate of the on-fault MFD (red or magenta curve in Figure 16). The implied coupling coefficients, listed in the , range from 0.37 to 0.75 among all the GR branches in Figure 3 (slip rate reductions of sixty-three to twenty-five percent). One option for matching the target MFDs is to apply these implied coupling coefficients, which can be done via two of the Moment Rate Fix” “Fault options in the UCERF3 logic tree (Figure 3): reduce the slip rates on all fault sections by the Apply Implied Coupling Coefficient – implied coupling coefficient (same reduction on all faults). let the inversion decide where to reduce slip rates in matching the target Do Nothing – MFD.
The GR hypothesis states that each fault section nucleates a GR distribution of earthquakes, with a b-value of 1.0 and a maximum magnitude defined by the largest rupture in which the section participates, including multi-fault ruptures. The rate of events, or the GR for each fault section can then be found by satisfying the section moment rate. Even before any inversion, we can sum all the consequent fault-section MFDs to obtain a total on-fault MFD. Two examples are shown in Figure 16. The red curve, which represents the ABM Deformation model paired with the Shaw09mod magnitude-area Relationship, exceeds not only the on-fault target (orange) but also the total regional target (black). The magenta curve, which represents the Zeng Deformation Model pared with the HanksBakun08 magnitude-area relationship, is just below the total target, and well above the on-fault target. Results for all other GR branches fall between these two cases. This discrepancy can be quantified as an on-fault coupling coefficient, defined as the ratio of the total rate of the target on-fault MFD (orange in Figure 16) to the total rate of the on-fault MFD (red or magenta curve in Figure 16). The implied coupling coefficients, listed in the , range from 0.37 to 0.75 among all the GR branches in Figure 3 (slip rate reductions of sixty-three to twenty-five percent). One option for matching the target MFDs is to apply these implied coupling coefficients, which can be done via two of the “Fault Moment Rate Fix” options in the UCERF3 logic tree (Figure 3): Apply Implied Coupling Coefficient – reduce the slip rates on all fault sections by the implied coupling coefficient (same reduction on all faults). Do Nothing – let the inversion decide where to reduce slip rates in matching the target MFD. value,
UCERF3pt3_Report_v13.tmpt1.docx