William E. Holt
B.S., Northern Arizona University, 1983
My main areas of research involve the investigation into the kinematics and dynamics of large-scale deformation of the Earth's crust and upper mantle.
Kinematics of Deforming Continental Lithosphere
Over the past 10 years I have been working on methods that relate the diffuse distribution of strain within continental interiors to the relative motion of the plates. The complete determination of the kinematics of the deformation is vital to understanding the dynamics of deforming continental lithosphere. An understanding of the kinematics is also the key to the quantification of seismic hazards within these zones of active deformation. The method we use involves the integration of strain rates on the surface of the Earth to determine relative velocities and rotations. The strain rates are obtained from Quaternary rates of slip on the major structures. Seismic moment tensors are used to place constraints on directions and styles of active deformation. GPS observations are the most important data set that we use to directly constrain the velocity gradients within deforming zones.
Dynamics of Deforming Continental Lithosphere
Our work on the kinematics provides a quantitative basis upon which to investigate the driving mechanisms (dynamics) for continental deformation. I am currently funded by NSF to examine the dynamics of crustal deformation. We use topographic data, the geoid, and seismically determined crustal thickness values to infer gravitational potential energy estimates within the lithosphere. We then solve force balance equations to determine stresses associated with these density variations within the lithosphere. Stress boundary conditions added to the stresses associated with density variations provide a final estimate of the total stress field. The magnitudes of stresses divided by strain rates inferred from our kinematic estimates provide first order estimates of the vertically averaged viscosity of the lithosphere. We also perform forward modeling of the dynamics, given initial estimates of viscosity, velocity boundary conditions (from the kinematic modeling), and gravitational potential energy estimates. These forward models enable us to refine solutions for the dynamics. I am working with PhD student Lucy Flesch and John Haines at Cambridge University, England on the dynamics of both western North America, and central and eastern Asia.
Global Strain Rate Map
I am funded through NASA with Geoffrey Blewitt at University of Nevada, Reno, to develop a self-consistent estimate of a velocity gradient tensor field. on the surface of the earth. This work is being performed by my PhD student Corné Kreemer and also in collaboration with John Haines. This research is also a contribution toward the estimation of a global strain rate map under the auspices of the IUGG and ILP (International Lithosphere Program). Results to date for the ILP Global Strain Rate Map Project are now archived at a UNAVCO web site.
Continental Deformation, Mantle Strain, and Shear Wave Splitting
We are investigating the relationship between shear wave splitting observations, mantle strain, and surface strains. We have found within Asia that there is a strong correlation between surface strains and the directions of fast polarization of shear wave splitting observations. I am working with Paul Silver at DTM investigating the the relationship between fast polarization directions there and the surface deformation field. We find a strong correlation between fast directions and the directions of the local surface velocity field in a hotspot frame of reference
Silver, P. G., and W.E. Holt, The mantle flow field beneath western North America, Science, 295, 1054-1057, 2002.
Flesch, L. M., Haines, A.J., and W.E. Holt, The dynamics of the India-Eurasia Collision Zone, J. Geophys. Res., 106, 16,435-16,460,2001
Kreemer, C., W.E. Holt, A no-net-rotation model of present day surface motions, Geophys. Res. Lett. Geophys. Res. Lett., 28, 4407-4410, 2001
Kreemer, C., W.E. Holt and J. Haines, The global moment rate distribution within plate boundary zones, in 'PLate Boundary Zones', AGU Monograph, eds. S Stein and J. Freymueller, accepted, 2001
Kreemer, C., J. Haines, W.E. Holt, G. Blewitt, and D. Lavallee, On the determination of a global strain model, Earth, Planets, and Space, 52, 765-770, 2000
Flesch, L.M., W.E. Holt, A.J. Haines, and B. Shen-Tu, Dynamic of the Pacific-North American plate boundary zone in the western United States, Science, 287, 834-836, 2000.
Flesch, L.M., A.J. Haines and W.E. Holt, The dynamics of the India-Eurasia collision zone, J. Geophys. Res., in review, 2000.
Holt, W. E., Correlated crust and mantle strain fields in Tibet, Geology, 28, 67-70, 2000.
Kreemer, C., J. Haines, W.E. Holt, G. Blewitt, and D. Lavallee, On the determination of a global strain rate model , Earth, Planets and Space, 52, 765-770, 2000.
Holt, W.E., N. Chamot-Rooke, X. Le Pichon, A.J. Haines, B. Shen-Tu, and J. Ren, Velocity field in Asia inferred from Quaternary fault slip rates and Global Positioning System observations, J. Geophys. Res., 105, 19,185-19,209, 2000.
Kreemer, C., and W.E. Holt, What caused the March 25, 1998 Antarctic plate earthquake?: inferences from regional stress and strain rate fields, Geophys. Res. Lett., 27 , 2297-2300, 2000.
Bernard, M.B., B. Shen-Tu, W.E. Holt, and D.M. Davis, Kinematics of active deformation in the Sulaiman Lobe and Range, Pakistan, J. Geophys. Res.,, 105, 13,253-13,279, 2000.
Kreemer, C., W.E. Holt, S. Goes, and R. Govers, Active deformation in eastern Indonesia and the Philippines from GPS and seismicity data, J. Geophys. Res., 105, 663-680, 2000.
Shen-Tu, B., W. E. Holt and A. J. Haines, The kinematics of the western United States estimated from Quaternary rates of slip and space geodetic data, J. Geophys. Res, 104, 28927-28955, 1999.
Holt, W. E., B. Shen-Tu, A. J. Haines, J. Jackson, On the determination of self-consistent strain rate fields within zones of distributed continental deformation, AGU Monograph on Dynamics of Global Plate Motions, In Press, 2000.
Shen-Tu, B., W. E. Holt and A. J. Haines, The contemporary kinematics of the Western United States determined from earthquake moment tensors, VLBI and GPS data, J. Geophys. Res., 103, 18,087-18,117, 1998.
Holt, W. E., Flow fields in the Tonga slab determined from the moment tensors of deep earthquakes, Geophys. Res. Lett., 22, 989-992, 1995.
Holt, W.E., M. Li, and A. J. Haines, Earthquake strain rates and instantaneous relative motions within central and east Asia, Geophys. Jour. Int., 122, 569-593, 1995.
Holt, W. E., and A. J. Haines, The kinematics of northern South Island New Zealand determined from geologic strain rates, J. Geophys. Res., 100, 17,991-18,010, 1995.
Shen-Tu, B., W. E. Holt, and A. J. Haines, Intraplate deformation in the Japanese Islands: A Kinematic study of intraplate deformation at a convergent plate margin, J. Geophys. Res., 100, 24,275-24,293, 1995.
Tinnon, M., W. E. Holt, and A. J. Haines, Velocity gradients in the northern Indian Ocean inferred from earthquake moment tensors and relative plate velocities, J. Geophys. Res., 100, 24,315-24,329, 1995.
Jackson, J. A., A. J. Haines, and W. E. Holt, The Accommodation of Arabia-Eurasia plate convergence in Iran, J. Geophys. Res., 100, 15,205-15,219, 1995.
Stern, T.A., and W. E. Holt, Platform Subsidence behind an active subduction zone, Nature, 368, 233-236, 1994.
Holt, W.E., and T.A. Stern, Subduction and foreland thrust loading: The late Tertiary development of Taranaki Basin, New Zealand, Tectonics, 13, 1068-1092, 1994.
Jackson, J., A.J. Haines, and W. E. Holt, A comparison of satellite laser ranging and seismicity data in the Aegean region, Geophys. Res. Lett., 21, 2849-2852, 1994.
Holt, W. E., and A. J. Haines, Reply to comment by R. Westaway on 'Velocity fields in deforming Asia from the inversion of earthquake-released strains', Tectonics, 12, 1489-1491, 1993.
Haines, A.J. and W.E. Holt, A procedure to obtain the complete horizontal motions within zones of distributed deformation from the inversion of strain rate data, J. Geophys. Res., 98, 12,057-12,082, 1993.
Holt, W.E., and A.J. Haines, Velocity fields in deforming Asia from the inversion of earthquake-released strains, Tectonics, 12, 1-20, 1993.
Stern, T.A., G.M. Quinlan, and W.E. Holt, Crustal dynamics associated with the formation of Wanganui Basin, New Zealand, South Pacific Sedimentary Basins. Sedimentary Basins of the World, 2, edited by P. F. Ballance (Series Editor: K.J. Hsu), 213-223, 1993.
Stern, T.A., G.M. Quinlan, and W.E. Holt, Basin formation behind an active subduction zone: three-dimensional flexural modeling of Wanganui Basin, New Zealand, Basin Research, 4, 197-214, 1992.
Jackson, J., A.J. Haines, and W.E. Holt, Determination of the complete horizontal velocity field in the deforming Aegean Sea region from the moment tensors of earthquakes, J. Geophys. Res., 97, 17,657-17,684, 1992.
Holt W.E. and T.A. Stern, Sediment loading on the western margin of New Zealand: Implications for the strength of a continental margin, Earth Planet. Sci. Lett., 107, 523-538, 1991.
Holt, W. E., and A.J. Haines, Kinematics of continental deformation, EOS, 72, p148, 1991.
Holt, W.E., J.F. Ni, T.C. Wallace, and A.J. Haines, The active tectonics of the Eastern Himalayan Syntaxis and Surrounding Regions, J. Geophys. Res., 96,14,595-14,632,1991.
Holt, W.E., and T.C. Wallace, Crustal thickness and upper mantle velocities in the Tibetan Plateau region from the inversion of regional Pnl waveforms: Evidence for a thick upper mantle lid beneath southern Tibet, J. Geophys. Res., 95, 12,499-12,525, 1990.
Ni, J.F., M. Guzman-Speziale, M. Bevis, W.E. Holt, T.C. Wallace and W.R. Seager, Accretionary tectonics of Burma and the three-dimensional geometry of the Burma subduction zone,Geology, 17, 68-71, 1989.
Holt, W.E., and T.C. Wallace, A procedure for the joint inversion of regional and teleseismic long-period body waves, Geophys. Res. Lett., 14, 903-906, 1987.
Holt, W.E., C. Chase and T. Wallace, Reply to comment by C. L. V. Aiken on "Crustal structure from three-dimensional modeling of a metamorphic core complex: A model for uplift, Santa Catalina - Rincon mountains, Arizona", Geology, 15, 979-980, 1987.
Holt, W.E., C. Chase and T. Wallace, Crustal structure from three-dimensional gravity modeling of a metamorphic core complex: A model of uplift, Santa Catalina-Rincon mountains, Arizona,Geology, 14, 927-930, 1986
News & Announcements
Geosciences Department Newsletter
Professor Martin Schoonen named Chairman of the Environmental Sciences Department at BNL
Professors John Parise and Artem Oganov pursue Materials Genome Initiative
Professor Deanne Rogers finds evidence for past groundwater on Mars
Professor Robert Liebermann accepts Edward A. Flinn Award
Professor Scott McLennan selected for NASA's Mars Science Laboratory Team