GPS measurements have provided invaluable time dependent deformation data following several recent earthquakes. The velocities and displacements determined from these methods are used as inputs to various models. At present, researchers laboriously transform the data formats into ones useable by their own individual programs. The current methods include FTP of data sets larger than needed, parsing of data by such UNIX commands as awk, sed, and grep, or transcription of information directly from printed papers. Object oriented programs served over web interfaces accessing standardized data will join the programs into simulations that will assimilate data and be self-consistent on many scales.
Elastic models use surface observations to estimate fault geometries and slip rates.
Viscoelastic calculations incorporate surface deformation, DEMs, and lab, heat-flow, stress, seismic and geologic data into models that produce estimates of crustal rheology and structure, fault geometry, fault slip and stress rates, heat flow, gravity, and refined estimates of surface deformation. These provide the inputs for quasi-static dynamic models of single faults and systems of faults. Simulations are critical to understanding the behavior of fault systems, a major problem in earth science, because earthquakes occur in the real earth at irregular intervals on timescales of hundreds to thousands of years. The simulations generate arbitrarily long seismicity catalogs and provide a numerical laboratory in which the physics of earthquakes can be investigated from a systems viewpoint. The simulations will provide invaluable feedback for the planning and design of future data collection efforts under the NASA Natural Hazards program.