Auxiliary Material for
Influence of fault connectivity on slip rates in southern California:
Potential impact on discrepancies between geodetic derived and geologic slip rates
Justin W. Herbert and Michele L. Cooke
(Department of Geosciences, University of Massachusetts, Amherst, Massachusetts)
Scott T. Marshall
(Department of Geology, Appalachian State University, Boone, North Carolina)
Journal of Geophysical Research, Solid Earth, 2014
Introduction
This data set contains information regarding model setup, tables containing average slip rates for faults, and additional GPS processing. We provide three-dimensional PDFs for each of our model setups to show the fault geometry and differences between our CFM-based and blocklike models. The files must be viewed using Adobe Acrobat or Acrobat Reader version 7.0 or later. Apple’s Preview, and other 3 rd
party pdf viewers cannot render 3D data. Tables contain the average net-, dip-, and strike-slip along faults for all three models presented here. Change in surface slip rates may not be representative of slip along the fault surface but the average slip rate for the entire fault surface, weighted by fault area, with standard deviation captures the variability of slip with depth.
1. fs01.pdf Three-dimensional PDF of faults within the discontinuous model (SCEC CFMbased).
2. fs02.pdf Three-dimensional PDF of faults within the SAF block-like model.
3. fs03.pdf Three-dimensional PDF of faults within the ECSZ block-like model.
4. ts01.eps Weighted average fault slip rates (Dip-, Strike-, and Net-slip), spatial variability, and tectonic sensitivity for our discontinuous model. All values are reported in mm/yr. Positive dipslip values indicate reverse-slip and positive strike-slip values indicate right-lateral. Average fault slip rates are for the entire fault surface, weighted by fault area, with standard deviation
(slip rate uncertainties associated with spatial variability along each fault and tectonic sensitivity), and represent the average of our the four boundary conditions tested. Spatial variability is assessed from the range in weighted average slip rates for the range in tectonic boundary conditions and owes to both topological variations along faults and interaction with nearby faults. Tectonic sensitivity is the range in weighted average slip rates for the four model boundary conditions we tested.
4.1 Column “Fault”, modeled fault name, locations are shown in Fig. 1.

4.2 Column “Dip-Slip”, mm/yr, average dip-slip rate for the entire fault surface, weighted by fault area, positive = reverse-slip and negative = normal-slip.
4.3 Column “DS-Spatial Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
4.4 Column “DS-Tectonic Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
4.5 Column “Strike-Slip”, mm/yr, average strike-slip rate for the entire fault surface, weighted by fault area, positive = right-lateral and negative = left-lateral.
4.6 Column “SS-Spatial Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
4.7 Column “SS-Tectonic Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
4.8 Column “Net-Slip”, average net-slip (total fault motion) rate for the entire fault surface, weighted by fault area.
4.9 Column “NS-Spatial Variability”, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
4.10 Column “NS-Tectonic Variability”, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
5. ts02.eps Weighted average fault slip rates (Dip-, Strike-, and Net-slip), spatial variability, and tectonic sensitivity for our SAF block-like model. All values are reported in mm/yr. Positive dipslip values indicate reverse-slip and positive strike-slip values indicate right-lateral. Average fault slip rates are for the entire fault surface, weighted by fault area, with standard deviation
(slip rate uncertainties associated with spatial variability along each fault and tectonic sensitivity), and represent the average of our the four boundary conditions tested. Spatial variability is assessed from the range in weighted average slip rates for the range in tectonic boundary conditions and owes to both topological variations along faults and interaction with nearby faults. Tectonic sensitivity is the range in weighted average slip rates for the four model boundary conditions we tested.
5.1 Column “Fault”, modeled fault name, locations are shown in Fig. 1.
5.2 Column “Dip-Slip”, mm/yr, average dip-slip rate for the entire fault surface, weighted by fault area, positive = reverse-slip and negative = normal-slip.
5.3 Column “DS-Spatial Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
5.4 Column “DS-Tectonic Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
5.5 Column “Strike-Slip”, mm/yr, average strike-slip rate for the entire fault surface, weighted by fault area, positive = right-lateral and negative = left-lateral.
5.6 Column “SS-Spatial Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
5.7 Column “SS-Tectonic Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
5.8 Column “Net-Slip”, average net-slip (total fault motion) rate for the entire fault surface, weighted by fault area.
5.9 Column “NS-Spatial Variability”, range in weighted average slip rates for the four models of

end member observations of plate velocity magnitude and orientation.
5.10 Column “NS-Tectonic Variability”, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
6. ts03.eps Weighted average fault slip rates (Dip-, Strike-, and Net-slip), spatial variability, and tectonic sensitivity for our ECSZ block-like model. All values are reported in mm/yr. Positive dip-slip values indicate reverse-slip and positive strike-slip values indicate right-lateral. Average fault slip rates are for the entire fault surface, weighted by fault area, with standard deviation
(slip rate uncertainties associated with spatial variability along each fault and tectonic sensitivity), and represent the average of our the four boundary conditions tested. Spatial variability is assessed from the range in weighted average slip rates for the range in tectonic boundary conditions and owes to both topological variations along faults and interaction with nearby faults. Tectonic sensitivity is the range in weighted average slip rates for the four model boundary conditions we tested.
6.1 Column “Fault”, modeled fault name, locations are shown in Fig. fs01.eps.
6.2 Column “Dip-Slip”, mm/yr, average dip-slip rate for the entire fault surface, weighted by fault area, positive = reverse-slip and negative = normal-slip.
6.3 Column “DS-Spatial Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
6.4 Column “DS-Tectonic Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
6.5 Column “Strike-Slip”, mm/yr, average strike-slip rate for the entire fault surface, weighted by fault area, positive = right-lateral and negative = left-lateral.
6.6 Column “SS-Spatial Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
6.7 Column “SS-Tectonic Variability”, mm/yr, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
6.8 Column “Net-Slip”, average net-slip (total fault motion) rate for the entire fault surface, weighted by fault area.
6.9 Column “NS-Spatial Variability”, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
6.10 Column “NS-Tectonic Variability”, range in weighted average slip rates for the four models of end member observations of plate velocity magnitude and orientation.
7. Figure fs04. Map showing the locations of ECSZ block-like model fault traces. Abbreviations are as follows: CHFZ - Crafton Hills Fault Zone, EPF - Eureka Peak Fault, GH - Garnet Hill,
MCS - Mission Creek Strand, PS - Pinto Splay, SAF - San Andreas Fault, and SJF - San Jacinto
Fault.
8. fs05.eps The raw detrended MEaSUREs time series for site AGMT before any time series analysis. Note the strong postseismic signal from the 1999 Hector Mine earthquake in the north time series. Also, an offset and smaller postseismic signal due to the 2010 El Mayor Cucapah earthquake is observed in the north time series. These non-interseismic motions are also present to a lesser degree in the east and vertical time series. For the analysis presented here, we have removed all data before 2004 for sites with similar postseismic motions for the Hector Mine

event. For the El Mayor Cucapah event, we have estimated and removed coseismic offsets for all sites, and the postseismic decay is effectively removed by removing the scaled first principal components of the stacked residual time series (Figure fs07)
9. fs06.eps Time series for site AGMT from its beginning (1999.9767) to the time of the El
Mayor Cucapah event (2010.2589). The time series plotted here has the secular velocity, annual, and semi-annual motions removed. The blue curves show the best fit of an exponential decay function, which provides an estimate of the postseismic relaxation. Based on visual fit to the data, we use a time decay constant of 1.1 years. The total estimated postseismic motions for the north, east, and vertical components are 16.95, 6.73, and 1.21 mm, respectively. Given this postseismic decay, negligible motion occurs after 2004 due to the Hector Mine event.
10. fs07.eps Detrended time series for site AGMT. Red triangles show the unprocessed raw time series. Blue inverted triangles show the time series after estimation and removal of coseismic and equipment change-related offsets, and annual and semi-annual motions. Green circles show the final detrended time series after removal of the scaled first principal components. Note that the removing the scaled first principal components have effectively removed the postseismic motions due to the 2010 El Mayor Cucapah event, leaving a dominantly linear time series, suggesting secular interseismic motion.
11. fs08.eps Detrended time series for site WWMT. Red triangles show the unprocessed raw time series. Blue inverted triangles show the time series after estimation and removal of coseismic and equipment change-related offsets, and annual and semi-annual motions. Green circles show the final detrended time series after removal of the scaled first principal components. Note that the removing the scaled first principal components have effectively removed the postseismic motions due to the 2010 El Mayor Cucapah event, leaving a dominantly linear time series, suggesting secular interseismic motion.
12. fs09.eps A) Comparison of interseismic velocities presented here with velocities from the
SCEC Crustal Motion Map version 4.0 (CMM) of Shen et al. [2011]. Only sites that are common to both data sets are shown. Note that the velocities and error ellipses are strikingly similar despite the fact that the CMM uses only data before 2004 and we use mainly data post 2004. B)
Residuals between the two velocity fields. Because the two velocity fields are so similar the residuals are scaled by a factor five relative to the map in A). If the residuals are plotted at the same scale as used in figure A) they are not clearly visible. The residuals show no clear systematic pattern, suggesting no systematic differences between the two data sets.