Production and Uses of Multi-Decade Geodetic Earth Science Data Records

Sharon Kedar, Yehuda Bock, Angelyn W. Moore, Peng Fang, Anne sullivan, Donald F. Argus, Songnian Jiang, & Scott T. Marshall

Published August 11, 2017, SCEC Contribution #7497, 2017 SCEC Annual Meeting Poster #091

The Solid Earth Science ESDR System (SESES) project funded under the NASA MEaSUREs program produces and disseminates mature, long-term, calibrated and validated, GNSS based Earth Science Data Records (ESDRs) that encompass multiple diverse areas of interest in Earth Science, such as tectonic motion, transient slip and earthquake dynamics, as well as meteorology, climate, and hydrology. The ESDRs now span twenty-five years for the earliest stations and today are available for thousands of global and regional stations.

Using a unified metadata database and a combination of GNSS solutions generated by two independent analysis centers, the project currently produces four long-term ESDR’s:
• Geodetic Displacement Time Series: Daily, combined, cleaned and filtered, GIPSY and GAMIT long-term time series of continuous GPS station positions (global and regional) in the latest version of ITRF, automatically updated weekly.
• Geodetic Velocities: Weekly updated velocity field + velocity field histories in various reference frames; compendium of all model parameters including earthquake catalog, coseismic offsets, and postseismic model parameters (exponential or logarithmic).
• Troposphere Delay Time Series: Long-term time series of troposphere delay (30-min resolution) at geodetic stations, necessarily estimated during position time series production and automatically updated weekly.
• Seismogeodetic records for historic earthquakes: High-rate broadband displacement and seismic velocity time series combining 1 Hz GPS displacements and 100 Hz accelerometer data for select large earthquakes and collocated cGPS and seismic instruments from regional networks.

We present several recent notable examples of the ESDR’s usage:
• A transient slip study that uses the combined position time series to unravel “tremor-less” slow tectonic transient events.
• Fault geometry determination from geodetic slip rates.
* Changes in water resources across California's physiographic provinces at a spatial resolution of 75 km.
• Retrospective study of a southern California summer monsoon event.

Key Words
GPS Geodesy "Earth Science Data Records" ESDR

Citation
Kedar, S., Bock, Y., Moore, A. W., Fang, P., sullivan, A., Argus, D. F., Jiang, S., & Marshall, S. T. (2017, 08). Production and Uses of Multi-Decade Geodetic Earth Science Data Records. Poster Presentation at 2017 SCEC Annual Meeting.

Related Projects & Working Groups
Tectonic Geodesy