Geoffrey (Geoff) Blewitt

Research Professor
Portrait of Geoffrey Blewitt

Contact Information

Degrees

  • Ph.D., Physics, California Institute of Technology, 1986
  • B.Sc., Physics, University of London, 1981

Biography

Geoff Blewitt has over 100 refereed publications and is cited in the literature over 9,500 times with an h-index of 46.

He graduated in 1986 with Ph.D. in Physics from Caltech (with John LoSecco and Nobel Prize winner Richard Feynman), working with the IMB collaboration (with Nobel Prize winner Fred Reines) on a high-energy physics experiment searching for proton decay. His thesis practically ruled out various theories that predicted a finite lifetime of ordinary matter.

In 1985 he joined Caltech's NASA Jet Propulsion Laboratory, where he was a lead developer of the GIPSY software, which analyzes GPS signals for high precision geodesy, which is the science of Earth's changing shape and rotation. He demonstrated centimeter-level global positioning, for which he won numerous NASA awards. In 1994, he joined the faculty of University of Newcastle, UK, and became Professor of Space Geodesy, where he turned his attention to applying GIPSY to Earth sciences, including plate tectonics and earthquakes.

Joining the Nevada Bureau of Mines and Geology at UNR in 1999, he became Professor of Geosciences, founding the Nevada Geodetic Laboratory. With projects funded by NASA, NSF, DOE, and USGS, his research uses data from over 16,000 GPS stations around the globe, imaging how the Earth changes its shape with time. Lessons from his research features in both undergraduate and graduate student courses in Physics, Geophysics, and Geology. In the Department of Physics, he is a founding member of the NSF-funded GPS.DM Collaboration, which uses subtle variations in GPS atomic clock signals to search for evidence of new, exotic physics, including dark matter.

He is a winner of the American Astrophysical Society's Brunno Rossi Prize (1987) for "The Detection of Neutrinos from Supernova 1987A", and the European Geosciences Union Vening Meinesz Medal (2015) "for his pioneering developments in geodetic theory, for advancing GPS for scientific research and applications, and for his outstanding contributions in applying geodesy to study geophysical and climate processes. He is co-inventor on Caltech patents related to hi-tech GPS analysis systems. He was awarded Fellow of the American Geophysical Union (2005), Fellow of the International Association of Geodesy (1999), and is a member of the American Physical Society.

Research Interests

  • Space geodesy and physical applications including satellite microwave signal processing
  • millimeter global positioning
  • centimeter satellite orbit determination
  • sub-nanosecond atomic clock determination
  • sub-millimeter/year station velocity determination
  • Earth's changing shape, gravity, and rotation; sea level; plate tectonics
  • earthquake cycle
  • surface mass loading
  • isostasy; natural hazards
  • GPS sensing of atmospheric water vapor
  • fundamental physics and the search for dark matter

Courses taught

  • PHYS 484/684(2012,2016): Special Topics in Physics - Physics of GPS
  • PHYS 771V(2014): Advanced Topics in Physics - Physics of GPS
  • GPH 411/611(2017): Geophysical Geodesy
  • GPH 455/655(2016): Geophysics and Geodynamics
  • GEOL 701i(2013,2015,2017): Advanced Geology - Geodesy

Publications

  • Roberts, B.M., G. Blewitt, C. Dailey, M. Murphy, M. Pospelov, A. Rollings, J. Sherman, W. Williams, and A. Derevianko (2017), Search for domain wall dark matter with atomic clocks on board global positioning system satellites, Nature Communications, 1195, doi: 10.1038/s41467-017-01440-4
  • Blewitt, G., C. Kreemer, W.C. Hammond, and J. Gazeaux (2016). MIDAS robust trend estimator for accurate GPS station velocities without step detection, Journal of Geophysical Research, 121, doi:10.1002/2015JB012552
  • Hammond, W.C., G. Blewitt, C. Kreemer (2016). GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift, Journal of Geophysical Research - Solid Earth, doi: 10.1002/2016JB013458
  • Hamlington, B.D., P.R. Thompson, W. Hammond, G. Blewitt, and R. Ray (2016). Assessing the impact of vertical land motion on estimates of 20th century global mean sea level. Journal of Geophysical Research, Oceans, 121, 4980-4993, doi:10.1002/2016JC011747
  • Blewitt, G. (2015). Terrestrial reference frame requirements for studies of geodynamics and climate change. International Association of Geodesy Symposia, 8 pp., Springer, Berlin. doi:10.1007/1345_2015_142
  • Blewitt, G. (2015). GPS and space-based geodetic methods. In G. Schubert (Ed.), Treatise in Geophysics (Second Edition), Vol. 3: Geodesy, 307-338, Elsevier, Oxford. doi:10.1016/B978-0-444-53802-4.00060-9
  • Donnellan, A., L.G. Ludwig, J.W. Parker, J.B. Rundle, J. Wang, M. Pierce, G. Blewitt, and S. Hensley (2015). Potential for a large earthquake near Los Angeles inferred from the 2014 La Habra earthquake, Earth and Space Science, 2. doi:10.1002/2015EA000113
  • Amos, C. B., Audet, P., Hammond, W. C., Burgmann, R., Johanson, I. A., Blewitt, G. (2014). Uplift and seismicity driven by groundwater depletion in central California. Nature, 509, 483-486, doi:10.1038/nature13275
  • Kreemer, C. W., Blewitt, G., Klein, E. C. (2014). A geodetic plate motion and global strain rate model. Geochemistry, Geophysics, Geosystems, 15(10), 3849-3889, doi:10.1002/2014GC005407
  • Blewitt, G., C. Kreemer, W.C. Hammond, and J.M. Goldfarb (2013). Terrestrial reference frame NA12 for crustal deformation studies in North America. Journal of Geodynamics, 72, pp. 11-24, ISSN