DOI: 10.5281/zenodo.4382937
title: Postseismic Corrected Walker Lane GPS velocities

description: The interseismic motion of GPS stations in a tectonically active, diffuse, strike-slip shear zone<br> provide constraints on the overall deformation budget that can be compared to the summation<br> of geologically-estimated fault slip rates to understand regional strain accommodation. The<br> Walker Lane GPS velocities in this dataset represent a subset of GPS stations included in the<br> Nevada Geodetic Laboratory MIDAS velocity solution (Blewitt et al., 2016, 2018; accessible at<br> http://geodesy.unr.edu/velocities/midas.NA12.txt, last accessed 11/19/2020) . This dataset<br> includes velocities for all GPS stations located between 34° N – 43° N latitude and 114° W –<br> 123° W longitude with time series longer than 2.5 years from the semi-continuous MAGNET<br> network operated by the Nevada Geodetic Laboratory (Blewitt et al., 2009) and neighboring<br> continuous GPS stations. The MIDAS velocities are calculated using daily position data collected<br> through August 2019 presented in the NA12 reference frame (Blewitt et al., 2013) , and<br> corrected for the postseismic effects of historic ruptures in and surrounding the Walker Lane.<br> The MIDAS algorithm is a median trend estimator that mitigates both seasonality and step<br> discontinuities in the times series (Blewitt et al., 2016). The resulting velocities are insensitive to<br> the coseismic and postseismic effects of earthquakes that occurred after the midpoint of the<br> time series (Blewitt et al., 2016) , such as the July 2019 Ridgecrest, CA M w 6.4 and 7.1 sequence,<br> but must be corrected for the post-seismic effects of earthquakes that occurred prior to the<br> middle of time series, such as the historic surface rupturing earthquakes in Central Nevada<br> Seismic Belt and the 1993 Landers M w 7.3, and 1999 Hector Mine M w 7.0 events. We apply the<br> viscoelastic postseismic relaxation correction from Bormann et al. (2013) that was developed<br> using the method of Hammond et al. (2010) and the preferred western Basin and Range lower<br> crust (10 20.5 Pa-s) and upper mantle (10 19 Pa-s) viscosity model of Hammond et al. (2009) .<br> When using this dataset, please also cite Blewitt et al (2018) as the authors of the original<br> MIDAS NA12 reference frame velocity solution is the basis for our postseismic corrected Walker<br> Lane velocities:<br> Blewitt, G., Hammond, W.C., Kreemer, C., 2018. Harnessing the GPS Data Explosion for<br> Interdisciplinary Science. Eos. https://doi.org/10.1029/2018EO104623.<br> <br> References:<br> Blewitt, G., Hammond, W.C., Kreemer, C., 2018. Harnessing the GPS Data Explosion for<br> Interdisciplinary Science. Eos. https://doi.org/10.1029/2018EO104623.<br> Blewitt, G., Kreemer, C., Hammond, W.C., Gazeaux, J., 2016. MIDAS robust trend estimator for<br> accurate GPS station velocities without step detection. Journal of Geophysical Research,<br> Solid Earth. https://doi.org/10.1002/2015JB012552.<br> Blewitt, G., Kreemer, C., Hammond, W.C., Goldfarb, J.M., 2013. Terrestrial reference frame<br> NA12 for crustal deformation studies in North America. Journal of Geodynamics.<br> https://doi.org/10.1016/j.jog.2013.08.004.<br> Bormann, J.M., Hammond, W.C., Kreemer, C., Blewitt, G., Jha, S., 2013. A Synoptic Model of<br> Fault Slip Rates in the Eastern California Shear Zone and Walker Lane from GPS Velocities<br> <br> for Seismic Hazard Studies. Presented at the 2013 Seismological Society of America Annual<br> Meeting, Seismological Research Letters, Salt Lake City, UT, p. 323.<br> Hammond, W.C., Kreemer, C., Blewitt, G., 2009. Geodetic constraints on contemporary<br> deformation in the northern Walker Lane: 3. Postseismic relaxation in the Central Nevada<br> Seismic Belt., in: Late Cenozoic Structure and Evolution of the Great Basin-Sierra Nevada<br> Transition, Geological Society of America Special Paper 447.<br> https://doi.org/10.1130/2009.2447(03).<br> Hammond, W.C., Kreemer, C., Blewitt, G., Plag, H.-P., 2010a. Effect of viscoelastic postseismic<br> relaxation on estimates of interseismic crustal strain accumulation at Yucca Mountain,<br> Nevada. Geophysical Research Letters. https://doi.org/10.1029/2010GL042795.