Z.-K. Shen (University of California Los Angeles)
D. C. Agnew (University of California San Diego)
R. W. King (Massachussetts Institute of Technology)
D. Dong (Jet Propulsion Laboratory)
T. A. Herring (Massachussetts Institute of Technology)
M. Wang (University of California Los Angeles)*
H. Johnson (University of California San Diego)*
G. Anderson (University of California San Diego)*
R. Nikolaidis (University of California San Diego)*
M. van Domselaar (University of California San Diego)*
K. W. Hudnut (U. S. Geological Survey)
D. D. Jackson (University of California Los Angeles)
*at time of contribution to this project.
This project has been a shared effort among many researchers. For Version 3, responsibility for producing the results was shared by Shen, Agnew, and King: Shen and King made independent estimates from the results of phase processing, with Agnew comparing the results, and cross-checking possible problems; and all three working to achieve a consensus result. Dong provided the EDM data in a form suitable for combination with the GPS, cleaning up many inconsistencies in the process. Herring provided the VLBI analysis and developed many of the tools used for automated processing of the large amounts of GPS data in Version 3; Wang performed manual processing of selected difficult data sets. Johnson and Anderson developed and implemented the data-archiving effort for survey-mode data. Nikolaidis and van Domselaar reprocessed an enormous amount of permanent data to produce orbits and analyses which were very useful. Hudnut took a lead role in the production of Versions 1 and 2 of the CMM; Jackson was responsible for instigating the idea of the CMM within SCEC, and both tirelessly championed it over the last decade.
This project depended first and foremost on many efforts to collect EDM data, survey-mode GPS data, and continuous GPS data. The EDM data collection was begun by Jim Savage and Will Prescott; we thank them, and Mike Lisowski, for making the data available and resolving many issues.
For the majority of our sites, the data came from survey-mode (``campaign'') measurements; we thank all those who organized such efforts, the very many observers who collected the data (often under trying conditions) and the landowners who provided access. The figure below summarizes the sources of the survey-mode GPS data; for making such data available we especially thank Gerald Bawden (UC Davis), Tim Dixon (JPL/University of Miami), Don D'Onfrio (Caltrans), Andrea Donnellan (JPL), Javier Gonzalez (CICESE), Brad Hager (MIT), Louise Kellog (UC Davis), Greg Lyzenga (Harvey Mudd), Meghan Miller (Central Washington University), Frank Monastero and Steve Bjornstad (US Navy), William Prescott (USGS), Robert Reilinger (MIT), Jay Satalich (Caltrans), Karen Wendt (USGS), and William H. Young (Riverside County Flood Control). Michael Cline and Mercedes Kim (UCLA) were responsible for collecting a considerable volume of data with SCEC funding. For the next step in the process, archiving data, we thank David Potter and Steve Salyards (UCLA) for assembling much of the data, and Li-Yu Sung (UCLA) for devising and implementing station-positioning software. Don Elliot, Heidi Buck, Pam Lehr, and Annika Green (UCSD) accurately decoded and transcribed thousands of logsheets.
The continuous GPS data from southern California and elsewhere made it possible to work consistently over the long time covered by these observations. For his pioneering efforts to establish continuous GPS in southern California, for his persistence in maintaining and expanding the network, and for his determination to make all the data, local and global, readily and reliably available through the SOPAC data center, we owe a great deal to the sustained efforts of Yehuda Bock (UCSD). The more recent expansion of the SCIGN network owes much to the efforts of many people, including K. Hudnut and W. H. Prescott (USGS), F. Webb (JPL), Y. Bock (UCSD) and J. McRaney (USC).
The processing task was made much easier by the excellent support provided by Peng Fang, assisted by Paul Jamason, Michael Scharber, Linette Prawirodirdjo, Brent Gilmore, Jeff Dean, and Chris Roelle, at the SOPAC data center (UCSD); and by Simon McClusky (MIT). SOPAC also provided computational resources. In the final step of evaluating the spatial consistency of velocities, we benefited greatly through our interaction with the fault-modeling work of Brendan Meade (MIT).
The initial collection of the data used here was funded under many grants and programs, notably by the National Science Foundation, the US Geological Survey, and NASA. The funding for this specific project, and the commitment to making it happen, lie with the Southern California Earthquake Center (SCEC) [of which this is contribution XXX] and we thank the successive Directors (K. Aki, D. Jackson, J.-B. Minster, and T. H. Jordan) and the rest of the SCEC community, for their support and patience.