Now Some Implications of Deformation Models & Seismicity Observations…
Moment Rates (1019 Nm/yr)
1. Include creep-based moment-rate reductions (default = 0.1). 2. 57% of Geologic on-fault increase (0.31) is from: Cerro Prieto (0.077 1019 Nm/yr); Mendocino (0.054 1019 Nm/yr);
and Brawley (Seismic Zone) alt 1 (0.049 1019 Nm/yr). 3. On-fault moment rate change for the same faults as used in the UCERF2 model.4. UCERF2 value includes both “C-Zones (aseismic)” and “Non-CA Faults” (treated as off fault here).5. Relative to the UCERF2 total value of 2.37 1019 Nm/yr, which includes contributions from “C-Zones (aseismic)”. 6. Assuming a truncated GR distribution with 8.7 M 5 events per year (Appendix L) and a b-value of 1.0
Increase on faults comes from addition of new faults; old faults came down a bit
57% of new fault increase is from three of the new faults.
Moment Rates (1019 Nm/yr)
1. Include creep-based moment-rate reductions (default = 0.1). 2. 57% of Geologic on-fault increase (0.31) is from: Cerro Prieto (0.077 1019 Nm/yr); Mendocino (0.054 1019 Nm/yr);
and Brawley (Seismic Zone) alt 1 (0.049 1019 Nm/yr). 3. On-fault moment rate change for the same faults as used in the UCERF2 model.4. UCERF2 value includes both “C-Zones (aseismic)” and “Non-CA Faults” (treated as off fault here).5. Relative to the UCERF2 total value of 2.37 1019 Nm/yr, which includes contributions from “C-Zones (aseismic)”. 6. Assuming a truncated GR distribution with 8.7 M 5 events per year (Appendix L) and a b-value of 1.0
Off-fault increases are from 11% to 45%
These off-fault moment rates are not used to constrain UCERF3 (but rather provide an implied off-fault aseismcity)
Deformation Model Moment RatesUCERF2 (2.1) Geologic ABM NeoKinema Zeng
On
faul
tO
ff Fa
ult
Tota
lRa
tio to
U3
Ave +2
-2
log10(Ratio)
1013
1015
1017
Mo Rate(Nm/yr)
UCERF3 Ave
Moment RatesAverage Deformation
ModelUCERF2 Smooth Seismicity Implied
UCERF3 Smooth Seismicity Implied
(Geologic, Zeng, ABM, & NeoKinema) (Assuming same total moment rate as for Ave Def Mod & constant Mmax and b-value)
log(Moment Rate)
Smooth Seismicity Divided By Ave Deformation Model
log10(ratio)
UCERF2 UCERF3
Smooth Seismicity Divided By Ave Deformation Model
log10(ratio)
UCERF3
1) Temporal rate changesorange/red areas are more active (& green/blue less active) in recent times
2) Inadequate Declusteringunder declustered in orange/red areas (& over declustered in green/blue areas)
3) Aseismicitygreen/blue areas are more aseismic (at least at lower mags); this can’t explain orange/red areas (and we wouldn’t see aseis that only influences larger events like
on Creeping SAF)
4) Mmax Variabilityorange/red areas have lower Mmax & green/blue areas
have higher Mmax
5) b-value Variabilityorange/red areas have higher, & green/blue have lower b-value
6) Char MFDs On Faultswhere faults appear green/blue; rest of region would need to be a bit more orange/red.
7) Undetected Earthquakesin green/blue areas
8) No real significant differences (given uncertainties in both)?
UCERF2 Assumptions
Smooth Seismicity Divided By Ave Deformation Model
UCERF3
1) Temporal rate changesorange/red areas are more active (& green/blue less active) in recent times
2) Inadequate Declusteringunder declustered in orange/red areas (& over declustered in green/blue areas)
3) Aseismicitygreen/blue areas are more aseismic (at least at lower mags); this can’t explain orange/red areas (and we wouldn’t see aseis that only influences larger events like
on Creeping SAF)
4) Mmax Variabilityorange/red areas have lower Mmax & green/blue areas
have higher Mmax
5) b-value Variabilityorange/red areas have higher, & green/blue have lower b-value
6) Char MFDs On Faultswhere faults appear green/blue; rest of region would need to be a bit more orange/red.
7) Undetected Earthquakesin green/blue areas
8) No real significant differences (given uncertainties in both)?
Implied Mmax if both deformation models and smoothed seismicity are correct (assuming GR)
Now General Discussion