NeoKinema models for the UCERF3 block-modelling project

1. NeoKinema models for the UCERF3 block-modelling project Peter Bird UCLA

5. Our F-E grid is 2-D, and mainly composed of 15-km equilateral triangles. We use thin (4-km) strips of narrower elements to outline each block. Boundary velocities were taken from the preferred model of Bird [2009, JGR].

6. To improve stability of slip-rate estimates, we grouped the provided segments into “faults” of at least 60-km length, where possible. This means that each “fault” spans at least 4 finite-elements. It also means that geologic slip-rates are not point constraints, but apply all along each 60-km “fault.”

7. Stress directions interpolated from 638 World Stress Map data provide loose constraints on the orientation of strain-rates between faults.

8. 16 GPS velocities (<1%) were deleted from our input data after they were found to have misfits >14 mm/a, and to be seriously discrepant with neighboring GPS velocities. The “triple bug” near Cholame was the most egregious.

9. NeoKinema corrects GPS velocities from “interseismic” to “long-term” before using them as constraints on the long-term velocity solution. This can be done in 2 ways: *Iterated geodetic adjustment uses fault slip-rates from the previous iteration. In this project, the “iga” method failed because it always generated at least one local instability. *Conservative geodetic adjustment is based on geologic slip rates (or geologic prior rates, in absence of offset features. This “cga” method was used in the reported models.

10. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

11. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

12. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

13. Preferred model GCN2008088 of Bird [2009, JGR]

14. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

15. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

16. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

17. Preferred model GCN2008088 of Bird [2009, JGR]

18. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

19. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

20. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

21. Preferred model GCN2008088 of Bird [2009, JGR]

22. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

23. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

24. 3 “satisfactory” models are reported here: *no weight on geologic slip rates (except in cga); uniform locking depth 15 km. *no weight on geologic slip rates (except in cga); variable locking depth per UCERF2 WGCEP Fault Model 2.2. *optimal weight on geologic slip rates, variable locking depths (UCERF2), & cga.

25. Preferred model GCN2008088 of Bird [2009, JGR]