Analysis of Vertical Velocities from BARGEN Continuous GPS Data at Yucca Mountain, Southern Nevada

We present vertical velocity results for the continuous GPS network located in the region of Yucca Mountain, southern Nevada. Based on local and regional tectonics, we hypothesize that vertical velocities at Yucca Mountain are likely to be very small. Data from the network, from May 1999 to January 2003, was processed using the GIPSY-OASIS II software, with ambiguities resolved on a line-by-line basis to produce baseline velocities relative to a station located in the center of the Yucca Mountain network. Radome changes made in late-1999 produce a signal in the data, due to the fact that radomes were changed first at Yucca Mountain itself and later at stations in the far-field. Final results show vertical baseline velocities in the local Yucca Mountain network, relative to a station in the center of the network, clustered tightly around zero. All vertical velocities < 55 km from Yucca Mountain range between -0.6 ± 0.2 mm/yr and 0.7 ± 0.2 mm/yr, with an RMS of 0.63 about zero. We also show that stations in the regional network around Yucca Mountain show small velocity trends in their timeseries.