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