Curriculum Vitae DON HELMBERGER Professor of Geophysics

Seismological Laboratory 252-21 California Institute of Technology Pasadena, CA 91125 Tel. (626) 395-6998; Fax (626) 564-0715 Email: [email protected]

EDUCATION: B. A. (Geophysics) University of Minnesota (five year curriculum), 1962 M. S. University of California, San Diego, 1965. Ph.D. University of California, San Diego, 1967.

PROFESSIONAL EXPERIENCE: Research Associate, Department of Geology and Geophysics, MIT, 1968 Assistant Professor of Geophysics, Princeton University, 1969 Assistant Professor of Geophysics, California Institute of Technology, 1970-1974 Associate Professor of Geophysics, California Institute of Technology, 1974-1979 Professor of Geophysics, California Institute of Technology, 1979 - present. Director, Seismological Laboratory, Caltech, May 1998-May 2003

RECENT HONORS AND AWARDS: First American Geophysical Union recipient of the Inge Lehmann Medal, 1997 Smits Family Professorship, California Institute of Technology, 2000-2011 Medal of the Seismological Society of America, 2002 National Academy of Sciences Member, 2004

RESEARCH INTERESTS: Seismic wave propagation and the inversion of waveforms to recover detailed information about earthquake characteristics and earth structure; particularly interested in mapping ultra-low-velocity zones and possible post-perovskite effects at the Core-Mantle Boundary.

PUBLICATIONS: Helmberger, D. V. (1967). Head Waves from the Oceanic Mohorovicic Discontinuity, Ph.D. Thesis, University of California, San Diego, La Jolla, California. Helmberger, D. V. (1968). The crust-mantle transition in the Bering Sea, Seismol. Soc. Am. Bull., 58, No. 1, 179-214. Helmberger, D. V. and G. B. Morris (1969). A travel time and amplitude interpretation of a marine refraction profile, primary waves, J. Geophys. Res., 74, No. 2, 438-494. Helmberger, D. V. and G. B. Morris (1970). A travel time and amplitude interpretation of a marine refraction profile, transformed shear waves, Seismol. Soc. Am. Bull., 60, No. 2, 593-600. Staff and students, Div. Geol. and Planet. Sci., California Institute of Technology, including Helmberger, D. V. (1971). Preliminary seismological and geological studies

1 of the San Fernando, California, earthquake of February 9, 1971, Seismol. Soc. Am. Bull., 61, No. 2, 491-495. Gilbert, F. J. and D. V. Helmberger (1972). Generalized ray theory for a layered sphere, Geophys. J. R. Astron. Soc., 27, 57-80. Helmberger, D. V. (1972). Long-period body-wave propagation from 4o to 13o, Seismol. Soc. Am. Bull., 62, No. 1, 325-341. Helmberger, D. V. and D. G. Harkrider (1972). Seismic Source Descriptions of Underground Explosions and a Depth Discriminate, Geophys. J. R. Astron. Soc., 31, 45-66. Allen, C. R. and D. V. Helmberger (1973). Search for temporal changes in seismic velocities using large explosions in , Proc. Conf. on Tectonic Problems of the System, Stanford Univ. Publication, Geol. Sci., XIII, 436-445. Helmberger, D. V. (1973). Numerical seismograms of long period body waves from 17o to 40o, Seismol. Soc. Am. Bull., 68, No. 2, 633-646. Helmberger, D. V. (1973). On the structure of the low velocity zone, Geophys. J. R. Astron. Soc., 34, 251-263. Helmberger, D. V. and R. A. Wiggins (1973). Upper mantle structure of mid-western United States, J. Geophys. Res., 76, No. 14, 3229-3244. Mitchell, B. J. and D. V. Helmberger (1973). Shear velocities at the base of the mantle from observations of S and ScS, J. Geophys. Res., 78, No. 26, 6009-6020. Wiggins, R. A. and D. V. Helmberger (1973). Upper mantle structure of the western United States, J. Geophys. Res., 78, No. 11, 1870-1888. York, J. E. and D. V. Helmberger (1973). Low-velocity zone variations in the southwestern United States, J. Geophys. Res., 78, No. 11, 1883-1886. Burdick, L. J. and D. V. Helmberger (1974). Time functions appropriate for deep earthquakes, Seismol. Soc. Am. Bull., 64, No. 5, 1419-1428. Helmberger, D. V. (1974). Generalized Ray Theory for Shear Dislocations, Seismol. Soc. Am. Bull., 64, No. 1, 45-64. Helmberger, D. V. (1974). Understanding seismograms by constructing numerical models, Engineering and Sci., 38, No. 1, 26-29. Helmberger, D. V. and G. R. Engen (1974). Upper Mantle Shear Structure, J. Geophys. Res., 79, No. 26, 4017-4028. Langston, C. A. and D. V. Helmberger (1974). A procedure for modeling shallow dislocation sources, Geophys. J. R. Astron. Soc., 42, 117-130. Langston, C. A. and D. V. Helmberger (1974). Interpretation of body and Rayleigh waves from NTS to Tucson, Seismol. Soc. Am. Bull., 64, No. 6, 1919-1929. Mellman, G. R. and D. V. Helmberger (1974). High frequency attenuation by a thin high velocity layer, Seismol. Soc. Am. Bull., 64, No. 5, 1383-1388. Wiggins, R. A. and D. V. Helmberger (1974). Synthetic seismogram computation by expansion in generalized rays, Geophys. J. R. Astron. Soc., 37, 73-90. Helmberger, D. V. and S. D. Malone (1975). Modeling Local Earthquakes as Shear Dislocations in a Layered Half Space, J. Geophys. Res., 80, No. 35, 4881-4888. King, D. and D. V. Helmberger (1975). Time functions appropriate for some aftershocks following the Point Mugu, California earthquake of 21 February 1973, Seismol. Soc. Am. Bull., 65, No. 1, 127-132.

2 Mellman, G., L. Burdick, and D. V. Helmberger (1975). Determination of source parameters from long period wave seismograms, Earthquake Notes, 46, p. 44. Heaton, T. H. and D. V. Helmberger (1977). A study of the strong ground motion of the Borrego Mountain, California earthquake, Seismol. Soc. Am. Bull., 67, No. 2, 315- 330. Helmberger, D. V. (1977). Fine structure of an Aleutian crustal section, Geophys. J. R. Astron. Soc., 48, 81-90. Helmberger, D. V. and L. R. Johnson (1977). Source parameters of moderate size earthquakes and the importance of receiver crustal structure in interpreting observations of local earthquakes, Seismol. Soc. Am. Bull., 67, No. 2, 301-313. Hong, T.-L. and D. V. Helmberger (1977). Generalized ray theory for dipping structure, Seismol. Soc. Am. Bull., 67, No. 4, 995-1008. Burdick, L. J. and D. V. Helmberger (1978). The upper mantle P velocity structure of the western United States, J. Geophys. Res., 83, No. B4, 1699-1712. Harkrider, D. G. and D. V. Helmberger (1978). A note on non-equivalent quadruple source cylindrical shear potentials which give equal displacements, Seismol. Soc. Am., Bull., 68, No. 1, 125-132. Heaton, Thomas H. and D. V. Helmberger (1978). Predictability of strong ground motion in the Imperial Valley: Modeling the M = 4.9, November 4, 1976 Brawley earthquake, Seismol. Soc. Am. Bull., 68, No. 1, 31-48. Helmberger, D. V. and G. R. Engen (1978). Fine structure of an oceanic crustal section near the East Pacific Rise, Seismol. Soc. Am. Bull., 68, No. 2, 369-382. Helmberger, D. V. and D. G. Harkrider (1978). Modeling earthquakes with generalized ray theory: Modern Problems in Elastic Wave Propagation, IUTAM Symposium, eds. J. Miklowitz and J. Achenbach, John Wiley & Sons, New York, 499-518. Hong, T.-L. and D. V. Helmberger (1978). Glorified Optics and Wave Propagations in Non-Planar Structure, Seismol. Soc. Am. Bull., 68, No. 5, 1313-1330. Jennings, P. and D. V. Helmberger (1978). Strong motion : Proc. of the Second Int. Conf. on Microzonation, sponsored by UNESCO, 1, 27-41. Mellman, G. R. and D. V. Helmberger (1978). A modified first motion approximation for the synthesis of body wave seismograms, Geophys. J. R. Astron. Soc., 54, 129-140. Burdick, L. J. and D. V. Helmberger (1979). Time Functions Appropriate for Nuclear Explosions, Bull. Seismol. Soc. Am., 69, No. 4, 957-973. Heaton, Thomas H. and D. V. Helmberger (1979). Generalized Ray models of the San Fernando Earthquake, Seismol. Soc. Am. Bull. 69, No. 5, 1311-1341. Helmberger, D. V. and L. J. Burdick (1979). Synthetic Seismograms, Ann. Rev. of Earth and Planet. Sci., 7, 417-442. Helmberger, D. V., G. R. Engen, and P. Scott (1979). A note on velocity, density, and attenuation models for marine sediments determined from multi-bounce phases, J. Geophys. Res., 84, No. B2, 667-671. Helmberger, D. V. and P. C. Jennings (1979). Strong ground motion: Proc. of the Rancho Santa Fe Strong Motion Workshop, sponsored by the National Science Foundation, eds. P. Jennings and D. Helmberger, 102 p. Spudich, P. K. P. and D. V. Helmberger (1979). Synthetic seismograms from model ocean bottoms, J. Geophys. Res., 84, No. B1, 667-671. Hadley, David M. and D. V. Helmberger (1980). Simulation of strong ground motions, Seismol. Soc. Am. Bull., 70, No. 2, 617-630.

3 Helmberger, D. V. and G. R. Engen (1980). Modeling the long-period body waves from shallow earthquakes at regional ranges, Seismol. Soc. Am. Bull., 70, No. 5, 1699- 1714. Given, J. and D. V. Helmberger (1980). Upper mantle structure of northwest Eurasia, J. Geophys. Res., 85, No. B12, 1783-1794. Helmberger, D. V. and D. Hadley (1981). Seismic Source Functions and Attenuation from Local and Teleseismic Observations of the NTS Events JORUM and HANDLEY, Bull. Seismol. Soc. Am., 71, No. 1, 51-67. Lay, T. and D. V. Helmberger (1981). Body wave amplitude patterns and upper mantle attenuation variations across North America, Geophys. J. Roy. Astr. Soc., 66, 691- 726. Stewart, G. S. and D. V. Helmberger (1981). The Bermuda earthquake of March 24, 1978: A significant oceanic intraplate event, J. Geophys. Res., 86, No. B8, 7027- 7036. Wallace, T. C., D. V. Helmberger, and J. E. Ebel (198l). A broadband study of the August 13, 1978 Santa Barbara earthquake, Seismol. Soc. Am. Bull., 71, No. 6, 1701-1718. Wallace, T. C., D. V. Helmberger, and G. Mellman (1981). A technique for the inversion of regional data in source parameter studies, J. Geophys. Res., 86, No. B3, 1679- 1685. Cohn, S. N., T.-L. Hong, and D. V. Helmberger (1982). The Oroville earthquakes: A study of source characteristics and site effects, J. Geophys. Res., 87, No. B6, 4585- 4594. Ebel, J. E. and D. V. Helmberger (1982). P-wave complexity and fault asperities: The Borrego Mountain, California, earthquake of 1968, Seismol. Soc. Am. Bull., 72, No. 2, 413-438. Hadley, D. M., D. V. Helmberger, and J. A. Orcutt (1982). Peak acceleration scaling studies, Seismol. Soc. Am. Bull., 72, No. 3, 959-980. Hartzell, S. and D. V. Helmberger (1982). Strong-motion modeling of the Imperial Valley earthquake of 1979, Seismol. Soc. Am. Bull., 72, No. 2, 571-596. Ruff, L. J. and D. V. Helmberger (1982). The structure of the lowermost mantle determined by short-period P-wave amplitudes, Geophys. J. R. Astron. Soc., 68, 95- 119. Wallace, T. C. and D. V. Helmberger (1982). Determining source parameters of moderate-sized earthquakes from regional waveforms, Phys. Earth Planet. Inter., 30, 185-196. Helmberger, D. V. (1983). Theory and application of synthetic seismograms, in Earthquakes: Observation, Theory and Interpretation, LXXXV, corso, Vol. 37, edited by H. Kanamori and E. Boschi, 174-217, Soc. Italiana di Fisica, Bologna, Italy. Lay, T. and D. V. Helmberger (1983). A lower mantle S-wave triplication and the shear velocity structure of "D", Geophys. J. R. Astron. Soc., 75, 799-838. Lay, T. and D. V. Helmberger (1983). A Shear Velocity Discontinuity in the Lower Mantle, Geophys. Res. Lett., 10, No. 1, 63-66. Lay, T. and D. V. Helmberger (1983). Body-wave amplitude and travel time correlations across North America, Seismol. Soc. Am. Bull., 73, No. 4, 1063-1076. Lay, T. and D. V. Helmberger (1983). The Shear-wave velocity gradient at the base of the mantle, J. Geophys. Res., 88, No. B10, 8160-8170.

4 Liu, H.-L. and D. V. Helmberger (1983). The near-source ground motion of the 6 August 1979 Coyote Lake, California, earthquake, Seismol. Soc. Am. Bull., 73, No. 1, 201- 218. Scott, P. and D. V. Helmberger (1983). Applications of the Kirchhoff-Helmholtz integral to problems in seismology, Geophys. J. R. Astron. Soc., 72, 237-254. Wallace, T. C., D. V. Helmberger, and G. R. Engen (1983). Evidence of tectonic release from underground nuclear explosions in long-period P-waves, Seismol. Soc. Am. Bull., 73, No. 2, 593-613. Grand, S. P. and D. V. Helmberger (1984). Upper mantle shear structure beneath the northwestern Atlantic Ocean, J. Geophys. Res., 89, No. B13, 11,465-11,475. Grand, S. P. and D. V. Helmberger (1984). Upper mantle shear structure of North America, Geophys. J. R. Astron. Soc., 76, 399-438. Helmberger, D. V. and H.-L. Liu (1984). Strong motions in a basin: Symposium of the International Workshop on , Shanghai, China, January 5, 1984. Lay, T., L. B. Burdick, and D. V. Helmberger (1984). Estimating the Yields of the Amchitka Tests by Waveform Intercorrelation, Geophys. J. R. Astron. Soc., 78, 181- 208. Lay, T., D. V. Helmberger, and Harkrider, D. G. (1984). Source Models and Yield- scaling Relations for Underground Nuclear Explosions at Amchitka Island, Bull. Seismol. Soc. Am., 74, No. 3, 843 -862. Lay, T., T. C. Wallace, and D. V. Helmberger (1984). The effects of tectonic release on short-period P waves from NTS explosions, Seismol. Soc. Am. Bull., 74, No. 3, 819- 842. Rial, J. A., S. P. Grand, and D. V. Helmberger (1984). A note on lateral variation in upper mantle shear-wave velocity across the Alpine fronts, Geophys. J. R. Astron. Soc., 77, 639-648. Grand, S. P. and D. V. Helmberger (1985). Upper mantle shear structure beneath Asia from multi-bounce S waves, Phys. Earth Planet. Int., 41, 154-169. Helmberger, D. V., G. R. Engen, and S. P. Grand (1985). Notes on wave propagation in laterally varying structure, J. Geophys., v. 58, 82-91. Helmberger, D. V., G. R. Engen, and S. P. Grand (1985). Upper-mantle cross-section from California to Greenland, J. Geophys., 58, 92-100. Liu, H.-L. and D. V. Helmberger (1985). Modeling the near-source ground motion for the 23:19 aftershock of the October 15, 1979, Imperial Valley earthquake, Seismol. Soc. Am. Bull, v. 75, No. 3, 689-708. Scott, P. and D. V. Helmberger (1985). Applications of the transmitted Kirchhoff- Helmholtz method to transmitted body waves and possible structural effects at NTS, Seismol. Soc. Am. Bull., v. 75, No. 1, 131-156. Vidale, J. E., D. V. Helmberger, and R. W. Clayton (1985). Finite-Difference Seismograms for SH Waves, Seismol. Soc. Am. Bull., v. 75, No. 6, 1765-1782. Wallace, T. C., D. V. Helmberger, and G. R. Engen (1985). Evidence of Tectonic Release from Underground Nuclear Explosions in Long-period S Waves, Seismol. Soc. Am. Bull., 75, No. 1, 157-174. Webb, T., S. G. Wesnousky, and D. V. Helmberger (1985). A body-wave analysis of the 1966 Grisborne, New Zealand earthquake, Tectono-physics, 113, 271-282.

5 Barker, J. and D. V. Helmberger (1986). A broad-band study of attenuation in ocean bottom sediments, Chapter in Ocean Seismo-acoustics, eds., T. Akal and J. Berkson, Plenum Press, New York, N.Y., 609-621. Wallace, T. C., D. V. Helmberger, and T. Lay (1986). Note on the revised moments for Pahute Mesa tectonic release, Seismol. Soc. Am. Bull., 76, No. 1, 313-319. Burger, R. W., P. G. Somerville, J. S. Barker, R. B. Herrmann, and D. V. Helmberger (1987). The effect of crustal structure on strong ground motion attenuation relations in eastern North America, Seismol. Soc. Am. Bull., 77, No. 2, 420-439. Helmberger, D. V. (1987). Modeling multi-bounce phases in marine sediments, in Marine Geophysics: A Navy Symposium, ed. E. N. Shor and C. L. Ebrahimi, Marine Physical Laboratory Report No. MPL-U-42/87. Somerville, P. G., J. P. McLaren, L. V. LeFevre, R. W. Burger, and D. V. Helmberger (1987). Comparison of source scaling relations of Eastern and Western North American earthquakes, Seismol. Soc. Am. Bull., 77, No. 2, 322-346. Vidale, J. E. and D. V. Helmberger (1987). Path effects in strong motion seismology, Chapter 6, In Methods of Computational Physics (ed. Bruce Bolt) (Academic Press, New York), pp. 267-319. Garnero, E. J., D. V. Helmberger, and G. R. Engen (1988). Lateral variations near the core mantle boundary, Geophys. Res. Lett., 15, 609-612. Graves, R. W. and D. V. Helmberger (1988). Upper mantle cross-section from Tonga to Newfoundland, J. Geophys. Res., 93, No. B5, 4701-4711 Helmberger, D. V. and J. E. Vidale (1988). Modeling strong motions produced by earthquakes with two-dimensional numerical codes, Bull.Seismol. Soc. Am., 78, No. 1, 109-121. Stead, R. J. and D. V. Helmberger (1988). Numerical-analytical Interfacing in Two Dimensions with Application to Modeling NTS Seismograms, Pure Appl. Geophys., 128, 157-193. Vidale, J. E. and D. V. Helmberger (1988). Elastic Finite-Difference Modeling of the 1971 San Fernando, California Earthquake, Seismol. Soc. Am. Bull., 78, No. 1, 122- 142. Bent. A.L. and D. V. Helmberger (1989). Source complexity of the October 1, 1987, Whittier Narrows earthquake, J. Geophys. Res., 94, No. B7, 9458-9556. Bent, A. L., D. V. Helmberger, R. J. Stead, and P. Ho-Liu (1989). Waveform modeling of the November 1987 Superstition Hills earthquakes, Bull. Seismol. Soc. Am., 79, No. 2, 500-514. Ho-Liu, P. and D. V. Helmberger (1989). Modeling regional Love Waves: Imperial Valley to Pasadena, Bull. Seismol. Soc. Amer., 79, 1194-1209. LeFevre, L.V. and D. V. Helmberger (1989). Upper-mantle P-velocity Structure of the Canadian Shield, J. Geophys. Res., 94, 17749-17765. Dreger, D. S. and D. V. Helmberger (1990). Broadband Modeling of Local Earthquakes, Bull. Seismol. Soc. Am., 80, No. 5, 1162-1179. Somerville, P. G. and D. V. Helmberger (1990). The effect of crustal structure on the attenuation of strong motion in eastern north America, submitted to the Conference Proceedings, Fourth U.S. National Conference on Earthquake Engineering, 22 May 1990.

6 Wald, D. J., D. V. Helmberger, and S. H. Hartzell (1990). Rupture process of the l987 Superstition Hills earthquake from the inversion of strong motion data, Bull. Seismol. Soc. Am., 80, No. 5, 1079-1098. Wald, D. J., D. V. Helmberger, and T. H. Heaton (1990). Analysis of the Loma Prieta earthquake from the inversion of local strong motion and broadband teleseismic data, EOS, 71. Somerville, P. G., J. P. McLaren, and D. V. Helmberger (1990). The November 25, 1988 Saguenay, Quebec, earthquakes, Bull. Seismol. Soc. Am., 80, 1118-1143. Bent, Allison L. and D. V. Helmberger, 1991. A re-examination of historic earthquakes in the San Jacinto fault zone, California, Bull. Seismol. Soc. Am., 81, No. 6, 2289- 2309. Bent, Allison L. and D. V. Helmberger (1991). Seismic characteristics of earthquakes along the offshore extension of the Western , California, Bull. Seismol. Soc. Am., 81, 399-422. Dreger, Douglas S. and D. V. Helmberger (1991). Complex Faulting Deduced from Broadband Modeling of the February 28, 1990 Upland Earthquake (ML=5.5), Bull. Seismol. Soc. Am., v. 81, 1129-1144. Dreger, Douglas and D. V. Helmberger (1991). Source Parameters of the Sierra Madre Earthquake from Regional and Local Body Waves, Geophys. Res. Lett., 18, No. 11, 2015-2018. Helmberger, D. V., L. J. Burdick, and R. Stead (1991). Modeling Near-field NTS and Amchitka. In Geophysical Monograph 65: Explosion Source Phenomenology (eds. Steven R. Taylor, Howard J. Patton, and Paul G. Richards) (American Geophysical Union, 2000 Florida Avenue, NW, Washington, DC, 20009) pp. 35-45. Helmberger, D. V., D. S. Dreger, L. S. Zhao, S. Kedar, B. B. Woods and D. H. Harkrider (1991). Source retrieval from regional seismograms, submitted to the Proceedings of the 13th Annual Phillips Laboratory Workshop, Keystone Resort, Colorado, October 1991. Helmberger, D. V., L. S. Zhao, D. Dreger and V. LeFevre (1991). Exploration of the lower lithosphere; Northeastern United States. Phys. Earth Planet. Inter., 70, 22-38. Song, Xiaodong and Don V. Helmberger (1991). Velocity Structure Near Inner Core Boundary from Waveform Modeling., J. Geophys. Res., 97, 6573-6586. Wald, David J., D. V. Helmberger, and T. H. Heaton (1991). Rupture model of the 1989 Loma Prieta earthquake from the inversion of strong motion and broadband teleseismic data, Bull. Seismol. Soc. Am., 81, 1540-1572. Wald, David J., D. V. Helmberger, and T. H. Heaton (1991). The rupture initiation process of a large earthquake: Loma Prieta, Seismol. Res. Lett., 62. Wald, David J., D. V. Helmberger, and H. Kanamori (1991). The 1906 San Franciso earthquake revisited, EOS, 68. Wald, David J., D. V. Helmberger, and H. K. Thio (1991). Strong Motion and Broadband Teleseismic Analysis of the 1991 Sierra Madre, California, Earthquake, EOS, 72. Zhao, Lian-She and D. V. Helmberger (1991). Broadband modeling along a regional shield path, Harvard recording of the Saguenay earthquake, Geophys. J. Int., 105, 301-312. Zhao, Lian-She and D. V. Helmberger (1991). Geophysical implication from relocation of Tibetan earthquakes; Hot lithosphere, Geophys. Res. Lett., 18, No. 12, 2205- 2208.

7 Zhao, Lian-She, D. V. Helmberger, and D. G. Harkrider (1991). Shear-velocity structure of the crust and upper mantle beneath the Tibetan Plateau and southeastern China, Geophys. J. Int., 105, 713-730. Helmberger, D. V., R. Stead, P. Ho-Liu, and D. Dreger (1992). Broadband modeling of regional seismograms: Imperial Valley to Pasadena, Geophys. J. Int. 110, 42-54. Helmberger, D. V., P. G. Somerville, and E. J. Garnero (1992). The Location and Source Parameters of the Lompoc, California Earthquake of November 4, 1927, Bull. Seismol. Soc. Am., 82, 1678-1709. Helmberger, D. V., L. S. Zhao, D. Dreger, and V. LeFevre (1991). Exploration of the lower lithosphere; northeastern United States, Phys. of the Earth & Planet. Inter, 70, 22-38. Jones, Laura E., Jim Mori and D. V. Helmberger (1992). Short-Period Constraints on the Proposed Transition Zone Discontinuity, J. Geophys. Res., 97, No. B6, 8765- 8774. Song Xiaodong and D. V. Helmberger (1992). Velocity Structure Near the Inner Core Boundary from Waveform Modeling, J. Geophys. Res., 97, B5, 6573-6586. Wald, David J., S. H. Hartzell, and D. V. Helmberger (1992). Reply to Arthur Frankel's "Comments on 'Rupture process of the 1987 Superstition Hills earthquake from the inversion of strong motion data”, Bull. Seismol. Soc. Am, 82, 1519-1533. Dreger, Douglas S. and D. V. Helmberger (1993). Determination of Source Parameters at Regional Distances With Three-Component Sparse Network Data, J. Geophys. Res., 98, No. B5, 8107-8125. Garnero, Edward J., D. V. Helmberger, and S. P. Grand (1993). Constraining Outermost Core Velocity with SmKS waves, Geophys. Res. Lett., 20, 2463-2466. Garnero, E. J., S. P. Grand, and D. V. Helmberger (1993). Low P-Wave Velocity at the Base of the Mantle, Geophys. Res. Lett., 20, No.17, 1843-1846. Garnero, E. J., D. V. Helmberger and S. Grand (1993). Preliminary evidence for a lower mantle shear wave velocity discontinuity beneath the central Pacific, Phys. Earth Planet. Inter. 79, 335-347. Garnero, E. J. and D. V. Helmberger (1993). Travel times of S and SKS: Implications for Three Dimensional Lower Mantle Structure Beneath the Central Pacific, J. Geophys. Res., 98, B5, 8225-8241. Garnero, E. J., D. V. Helmberger, and L. J. Burdick (1993). Preliminary observations from using US-Soviet Joint Seismic Program data to model upper mantle triplications beneath Asia, Geophys. J. Int., 113, No. 1, 252-259. Helmberger, Donald V., D. Dreger, R. Stead, and Hiroo Kanamori (1993). Impact of Broadband Seismology on the Understanding of Strong Motions, Bull. Seismol. Soc. Am. 83, No. 3, 830-850. Jones, L. E., S. E. Hough, D. V. Helmberger (1993). Rupture Process of the June 28, , Geophys. Res. Lett., 20, No. 18, 1907-1910. Song, Xiaodong and D. V. Helmberger (1993). Anisotropy of Earth’s Inner Core, Geophys. Res. Lett., 20, No. 23, 2591-2594. Song, Xiaodong and D. V. Helmberger (1993). Effect of velocity structure in D” on PKP phases, Geophys. Res. Lett., 20, No. 4, 285-288. Wald, D. J., H. Kanamori and D. V. Helmberger (1993). Source Study of the 1906 San Francisco Earthquake, Bull. Seismol. Soc. Am., 83, 981-1019.

8 Wald, David J., T. H. Heaton, and D. V. Helmberger (1993). Strong Motion and Broadband Teleseismic Analysis of the 1989 Loma Prieta Earthquake for Rupture Process and Hazards Assessment, published in the U.S. Geological Survey Professional Paper, 27 pages. Woods, Bradley, Sharon Kedar and D. V. Helmberger (1993). ML:Mo as a Regional Seismic Discriminant, Bull. Seismol. Soc. Am., 83, 1167-1183. Zhao, Lian-She and D. V. Helmberger (1993). Source retrieval from broadband regional seismograms: Hindu Kush region, Phys. Earth Planet. Inter. 78, 69-95. Zhao, Lian-She and D. V. Helmberger (1993). Upper Mantle Compressional Velocity Structure Beneath the Northwest Atlantic Ocean, J. Geophys. Res., 98, B8, 14,185- 14,196. Saikia, C. K., D. S. Dreger, and D. V. Helmberger (1994). Modeling of Energy Amplification recorded within using irregular Structure, Bull. Seismol. Soc. Am., 84, No. 1, 47-61. Scrivner, C. W. and D. V. Helmberger (1994). Seismic Waveform Modeling in the , Bull. Seismol. Soc. Am., 84, No. 5, 1310-1326. Zhao, Lian-She and D. V. Helmberger (1994). Source Estimation from Broadband Regional Seismograms, Bull. Seismol. Soc. Am., 84, No. 1, 92-104. Garnero, Edward J. and D. V. Helmberger (1995). On seismic resolution of lateral heterogeneity in the Earth’s outermost core, Phys. of the Earth & Planet. Inter. 88, 117-130. Garnero, Edward J. and D. V. Helmberger (1995). A very slow basal layer underlying large-scale low-velocity anomalies in the lower mantle beneath the Pacific: evidence from core phases, Phys. of the Earth & Planet. Inter., 91, 161-176. Mori, Jim and D. V. Helmberger (1995). Localized boundary layer below the mid-Pacific velocity anomaly identified from a PcP precursor,J. Geophys. R., 100, No. B10, 20,359-20,365. Scrivner, Craig W. and D. V. Helmberger (1995). Preliminary Work on an Early Warning and Rapid Response Program for Moderate Earthquakes, Bull. Seismol. Soc. Am., 85, No. 4, 1257-1265. Song, Xiaodong and D. V. Helmberger (1995). Depth dependence of anisotropy of Earth’s inner core, J. Geophys. Res., 100, No. B7, 9805-9816. Song, Xiaodong and D. V. Helmberger (1995). A P-wave Velocity Model of the Earth’s core, J. Geophys. Res., 100, No. B7, 9817-9830. Song, Xi J., L. E. Jones, and D. V. Helmberger (1995). Source Characteristics of the 17 January 1994 Northridge, California Earthquake from Regional Broadband Modeling, Bull. Seismol. Soc. Am., 85, No. 6, 1591-1603. Garnero, Edward J. and D. V. Helmberger (1996). Seismic detection of a thin laterally varying boundary layer at the base of the mantle beneath the central-Pacific, Geophys. Res. Lett., 23, No. 9, 977-980. Helmberger, D. V., E. J. Garnero, and X. Ding (1996). Modeling two-dimensional structure at the core-Mantle Boundary, J. Geophys. Res., 101, No. B6, 13,963- 13,972. Helmberger, D. V. and B. Woods (1996). Regional Source Parameters, Seismic Energy, and Discrimination, in Monitoring a Comprehensive Test Ban Treaty, edited by E. S. Housebye and A. M. Dainty, Kluwer Academic Publishers, 365-383.

9 Jones, Laura E. and D. V. Helmberger (1996). Seismicity and stress-drop in the eastern Transverse ranges, Southern California, Geophys. Res. Lett., 23, No. 3, 233-236. Mori, Jim and D. V. Helmberger (1996). Large Amplitude Moho reflections (SmS) from Landers Aftershocks, Southern California, Bull. Seismol. Soc. Am., 86, 1845-1852. Song, Xi J. and D. V. Helmberger (1996). Source Estimation of Finite Faults from Broadband Regional Networks, Bull. Seismol. Soc. Am., 86, No. 3, 797-804. Song, Xi J., D. V. Helmberger and L. Zhao (1996). Broadband modeling of regional seismograms: the Basin and Range crustal structure, Geophys. J. Int., 125, 15-29. Zhao, Lian-She and D. V. Helmberger (1996). Regional Moments, Energy Levels, and a New Discriminant, Pure Appl. Geophys., 146, No. 2, 281-304. Zhu, Lupei and D. V. Helmberger (1996). Intermediate depth earthquakes beneath the India-Tibet collision zone, Geophys. Res. Lett., 23, No. 5, 435-438. Zhu, Lupei and D. V. Helmberger (1996). Advancement in Source Estimation Techniques Using Broadband Regional Seismograms, Bull. Seismol. Soc. Am., 86, No. 5, 1634-1641. Helmberger, D. V., L. S. Zhao and E. J. Garnero (1996). Construction of Synthetics for 2D structures; core phases, in Seismic Modeling of Earth Structure, Enzo Boschi, Goran Ekstrom and Morelli (Eds.). Ding, Xiaoming and D. V. Helmberger (1997). Modeling D" structure beneath Central America with broadband seismic data, Phys. Earth Planet. Inter., 101, 245-270. Pino, N. Alessandro and D. V. Helmberger (1997). Upper Mantle Compressional Velocity Structure Beneath the West Mediterranean Basin, J. Geophys. Res., 102, No. B2, 2953-2967. Saikia, C. K. and D. V. Helmberger (1997). Approximation of Rupture Directivity in Regional Phases Using Up-Going and Down-Going Wave Fields, BSSA, 87, No. 4, 987-998. Song, Xi J. and D. V. Helmberger (1997). The Northridge aftershocks, a source study with TERRAscope data, Bull. Seismol. Soc. Am., 87, No. 4, 1024-1034. Song, Xiadong and D. V. Helmberger (1997). PKP differential travel times: Implications for three-dimensional lower mantle structure, Geophys. Res. Lett., 24, 1863-1866. Wen, Lianxing and D. V. Helmberger (1997). Propagational Corrections for Basin Structure: Landers Earthquake, Bull. Seismol. Soc. Am., 87, No. 4, 782-787. Woods, B. B. and D. V. Helmberger (1997). Regional Seismic Discriminants using Wavetrain Energy Ratios, Bull. Seismol. Soc. Am., 87, No. 3, 589-605. Zhu, Lupei, D. V. Helmberger, C. K. Saikia, and B. B. Woods (1997). Regional waveform calibration in the Pamir-Hindu Kush region, J. Geophys. Res., 102, No. B10, 22,799-22,813. Garnero, E. J. and D. V. Helmberger (1998). Further structural constraints and uncertainties of a thin laterally varying ultralow-velocity layer at the base of the mantle, J. Geophys. Res., 103, No. B6, 12,495-12,509. Helmberger, D. V., L. Wen, and X. Ding (1998). Seismic evidence that the source of the Iceland hotspot lies at the core-mantle boundary, Nature, 396, 251-255. Jones, Laura E. and D. V. Helmberger (1998). Earthquake Source Parameters and Fault Kinematics in the Eastern California Shear Zone, Bull. Seismol. Soc. Am., 88, No. 6, 1337-1352. Melbourne, Tim and D. V. Helmberger (1998). Fine Structure of the 410 km Discontinuity, J. Geophys. Res., 103 (B5), 10,091-10,102.

10 Ritsema, Jeroen, S. Ni, and D. V. Helmberger (1998). Evidence for strong shear velocity reductions and velocity gradients in the lower mantle beneath Africa, Geophys. Res. Lett., 25, No. 23, 4245-4248. Sato, T. and D. V. Helmberger (1998). Estimates of Regional and Local Strong Motions during the Great 1923 Kanto, Japan Earthquake (M=8.1). Part 1: Source Estimation of a Calibration Event and Modeling of wave propagation paths, Bull. Seismol. Soc. Am., 88, 183-205. Sidorin, Igor, M. Gurnis, D. V. Helmberger, and X. Ding (1998). Interpreting D" seismic structure using synthetic waveforms computed from dynamic models, Earth and Planet. Sci. Lett., 163, 31-41. Song, Xi J. and D. V. Helmberger (1998). Pseudo Green's Functions and Waveform Tomography, Bull. Seismol. Soc. Am., 88, No. 1, 304-312. Song, Xiaodong, and D. V. Helmberger (1998). Seismic Evidence for an Inner Core Transition Zone, Science, 282, 924-927. Wen, Lianxing and D. V. Helmberger (1998). Ultra-Low Velocity Zones near the Core- Mantle Boundary from Broadband PKP Precursors, Science, 279, 1701-1703. Wen, Lianxing and D. V. Helmberger (1998). A two-dimensional P-SV hybrid method and its application to modeling localized structures near the core-mantle boundary, J. Geophys. Res., 103, No. B8, 17,901-17,918. Zhu, Lupei and D. V. Helmberger (1998). Moho Offset Across the Northern Margin of the Tibetan Plateau, Science, 281, 1170-1172. Ni, Sidao, X. Ding, D. V. Helmberger, and M. Gurnis (1999). Low-velocity structure beneath Africa from forward modeling, Earth and Planet. Sci. Lett., 170, 497-507. Scrivner, Craig W. and D. V. Helmberger (1999). Finite Difference Modeling of Two Aftershocks of the 1994 Northridge, California Earthquake, Bull. Seismol. Soc. Am., 89, 6, 1505-1518. Scrivner, Craig W. and D. V. Helmberger (1999). Variability of Ground Motions in Southern California − Data from the 1995-1996 Ridgecrest Sequence, Bull. Seismol. Soc. Am., 89, 3, 626-639. Sidorin, Igor, M. Gurnis, and D. V. Helmberger (1999). Dynamics of a phase change at the base of the mantle consistent with seismological observations, J. Geophys. Res., 104, No. B7, 15,005-15,023. Sidorin, Igor, M. Gurnis, and D. V. Helmberger (1999). Evidence for a Ubiquitous Seismic Discontinuity at the Base of the Mantle, Science, 286, 1326-1331. Helmberger, D. V., S. Ni, L. Wen, and J. Ritsema (2000). Seismic evidence for ultra low- velocity zones beneath Africa and eastern Atlantic, J. Geophys. Res., 105, B10, 23,865-23,878. Ji, Chen, D. V. Helmberger, and D. J. Wald (2000). Basin Structure Estimation by Waveform Modeling: Forward and Inverse Methods, Bull. Seismol. Soc. Am., 90, 4, 964-976. Ni, Sidao, X. Ding, and D. V. Helmberger (2000). Constructing Synthetics from Deep Earth Tomographic Models, Geophys. J. Int., 140, 71-82. Helmberger, D. V., X. J. Song, and L. Zhu ( 2001). Crustal complexity from regional waveform tomography: Aftershocks of the , California, J. Geophys. Res., 106, No. B1, 609-620.

11 Ji, Chen, D. V. Helmberger, T.-R. Song, K.-F. Ma, and D. J. Wald (2001). Slip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, Earthquake, Geophys. Res. Lett., 28, No. 23, 4379-4382. Luo, Shang-Nian, S. Ni, and D. V. Helmberger (2001). Evidence for a sharp lateral variation of velocity at the core-mantle boundary from multipathed PKPab, Earth Planet. Sci. Lett., 189, 155-164. Melbourne, T. and D. V. Helmberger (2001). Mantle Control of Plate Boundary Deformation, Geophys. Res. Lett., 28, No. 20, 4003-4006, doi:10.1029/2001 GL013167. Ni, Sidao and D. V. Helmberger (2001). Probing an Ultra-low velocity zone at the Core Mantle Boundary with P and S Waves, Geophys. Res. Lett., 28, No. 12, 2345-2348. Ni, Sidao and D. V. Helmberger (2001). Horizontal transition from fast (slab) to slow (plume) structures at the Core-Mantle Boundary, Earth Planet. Sci. Lett., 187, 301- 310. Saikia, Chandan K., D. V. Helmberger, R. J. Stead, and B. B. Woods (2001). Effects of Source RDP Models and Near-source Propagation: Implication of Seismic Yield Estimation, Pure Appl. Geophys., 158, 2173-2216. Savage, Brian and D. V. Helmberger (2001). Kursk Explosion, Bull. Seismol. Soc. Am., 91, 4, 753-759. Ji, Chen, D. Wald, and D. V. Helmberger (2002). Source Description of the 1999 Hector Mine, California Earthquake; Part I: Wavelet Domain Inversion Theory and Resolution Analysis, Bull. Seismol. Soc. Am., 92, No. 4, 1192-1207. Ji, Chen, D. Wald, and D. V. Helmberger (2002). Source Description of the 1999 Hector Mine, California Earthquake; Part II: Complexity of Slip History, Bull. Seismol. Soc. Am., 92, No. 4, 1208-1226. Melbourne, T. and D. V. Helmberger (2002). Whole mantle shear structure beneath the East-Pacific-Rise, J. Geophys. Res., 107, No. B9, 2204, doi:10.1029/2001 JB000332. Ni, Sidao, Eh Tan, M. Gurnis, and D. V. Helmberger (2002). Sharp Sides to the African Superplume, Science, 296, 1850-1852. Ji, Chen, D. V. Helmberger, D. J. Wald, and K.-F. Ma (2003). Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan earthquake, J. Geophys. Res., 108, No. B9, 2412. Ni, Sidao and D. V. Helmberger (2003). Ridge-like lower mantle structure beneath South Africa, J. Geophys. Res., 108, No. B2, 2094. Ni, Sidao and D. V. Helmberger (2003). Seismological Constraints on the South African super plume; could be the oldest distinct structure on Earth, Earth & Planet. Sci. Lett., 206, 119-131. Ni, Sidao, Vernon F. Cormier, and Don V. Helmberger (2003). A Comparison of Synthetic Seismograms for 2D structures: Semianalytical versus Numerical, Bull. Seismol. Soc. Am., 93, No. 6, 2752-2757. Ni, Sidao and D. V. Helmberger (2003). Further constraints on the African superplume structure, Physics of Earth and Planet. Inter., 140, 243-251. Savage, B., C. Ji, and D. V. Helmberger (2003). Velocity variations in the uppermost mantle beneath the southern Sierra Nevada and Walker Lane, J. Geophys. Res., 108, No. B7, 2325.

12 Ji, Chen, D. V. Helmberger, and D. J. Wald (2004). A Teleseismic Study of the 2002 Denali Fault, Alaska, Earthquake and Implications for Rapid Strong-Motion Estimation, Earthquake Spectra, 20, No. 3, 617-637. Savage, B. and D. V. Helmberger (2004). Complex Rayleigh waves resulting from deep sedimentary basins, Earth Planet. Sci. Lett., 218, 229-239. Savage, B. and D. V. Helmberger (2004). Site response from incident Pnl waves, Bull. Seismol. Soc. Am., 94, No. 1, 357-362. Song, Teh-Ru, D. V. Helmberger, and S. Grand (2004). Low velocity zone atop the 410 seismic discontinuity beneath the northwestern US, Nature, 427, 530-533. Helmberger, Don V. and S. Ni (2005). Approximate 3D Body-Wave Synthetics for Tomographic Models, Bull. Seismol. Soc. Am., 95, No. 1, 212-224. Helmberger, Don V., T. Lay, S. Ni, and M. Gurnis (2005). Deep mantle structure and the post-perovskite phase transition, Proceedings of the National Academy of Sciences, 102, no. 48, 17257-17263. Helmberger, Don V. and S. Ni (2005). Seismic Modeling Constraints on the South African Super Plume, in Earth’s Deep Mantle: Structure, Composition, and Evolution, AGU Monograph Series, 10.1029/160GM06. Ni, Sidao, Hiroo Kanamori, and Don Helmberger (2005). Energy radiation from the Sumatra earthquake, Nature, 434, 582. Ni, Sidao, D. V. Helmberger, and J. Tromp (2005). Three-dimensional structure of the African superplume from waveform modeling, Geophys. J. Int., 161, 283-294. Zhu, Lupei, Y. Tan, D. V. Helmberger, and C. Saikia (2006). Calibration of the Tibetan Plateau using regional seismic waveforms, Pure Applied Geophys., 163 (7), 1193- 1213. Song, Teh-Ru and D. V. Helmberger (2006). Low Velocity Zone atop the Transition Zone in the Western US from S Waveform Triplication, in Earth’s Deep Water Cycle, Geophysical Monograph Series, 168 (edited by S. Jacobson and S. Van der Lee), 195-213, AGU, Washington, D.C., doi:10.1029/168GM15. Song, Teh-Ru and D. V. Helmberger (2006). Probing lithospheric deformation near Rio- Grande Rift, southwestern United States using P and S wave broadband waveform, J. Geophys. Res., in press. Tan, Ying, Lupei Zhu, Don V. Helmberger, and Chandan Saikia (2006). Locating and Modeling Regional Earthquakes with Two Stations, J. Geophys. Res. 111, B01306- B01320. Chen, Min, Jeroen Tromp, Don Helmberger, and Hiroo Kanamori (2007). Waveform modeling of the slab beneath Japan, J. Geophys. Res., 112, B02305, doi:10.1029/2006JB004394. Konca, A. Ozgun, V. Hjorleifsdottir, T-R. Alex Song, J-P Avouac, D. V. Helmberger, Chen Ji, K. Sieh, R. Briggs, and A. Meltzner (2007). Rupture Kinematics of the 2005 Mw 8.6 Nias-Simeulue Earthquake from the Joint Inversion of Seismic and Geodetic Data, BSSA, 97, No. 1A, S307-S322. Song, Teh-Ru and D. V. Helmberger (2007). A depleted, destabilized continental lithosphere near the Rio Grande rift, Earth Planet. Sci. Lett., 262, 175- 184,doi:10.1016/j.epsl.2007,07.052. Sun, Xinlei, Xiaodong Song, Sihua Zheng, and Don V. Helmberger (2007). Evidence for a chemical-thermal structure at base of mantle from sharp lateral P-wave variations

13 beneath Central America, Proceedings of the National Academy of Sciences, 104, no. 1, 26-30. Sun, Daoyuan, D. V. Helmberger, Xiaodong Song, and S. Grand (2007). Predicting a Global Perovskite and Post-Perovskite Phase Boundary, AGU Geophys. Monograph series. Sun, Daoyuan, Eh Tan, D. V. Helmberger, and M. Gurnis (2007). Seismological support for the metastable superplume model, sharp features, and phase changes,within the lower mantle, Proceedings of the National Academy of Sciences, 104, no. 22, 9151- 9155. Tan, Ying and D. V. Helmberger (2007). Trans-Pacific Upper Mantle Shear Velocity Structure, J. Geophys. Res., 112, B08301, doi:10.1029/2006JB004853. Song, Teh-Ru and D. V. Helmberger (2007). Validating Tomography with Broadband Waveform Modeling: An Example at LA RISTRA Transect in the southwestern United States, Geophys. J. Int., 171, 244-258. Song, Teh-Ru Alex and D. V. Helmberger (2007). Probing the lithosphere at Rio Grande Rift. southwestern United States using P and S Wave Broadband Waveform, J. Geophys. Res., 112, B0739, doi:10.1029/2007JB004942. Tan, Ying and D. V. Helmberger (2007). A New Method for Determining Small Earthquake Source Parameters Using Short-period P waves, Bull. Seismol. Soc. Am., 97, No. 4, 1176-1195. Sun, Daoyuan and D. V. Helmberger (2008). Lower mantle tomography and phase change mapping, J. Geophys. Res., 113, B10305, doi: 10.1029/2007JB005289. Chu, Risheng, Lupei Zhu, and Don V. Helmberger (2009). Determination of earthquake focal depths and source time functions in central Asia using teleseismic P waveforms, Geophys. Res. Lett., 36, L17317, doi:10.1029/2009GL030404. Song, Teh-Ru Alex, D. V. Helmberger, M. R. Brudzinski, R. W. Clayton, P. Davis, X. Perez-Campos, and S. K. Singh (2009). Subducting Slab Ultra-Slow Velocity Layer Coincident with Silent Earthquakes in Southern Mexico, Science, 324, 502-506. Sun, Daoyuan, D. V. Helmberger, S. Ni, and Dan Bower (2009). Direct Measures of Lateral Velocity Variation in the Deep Earth, J. Geophys. Res., 114, B05303, doi:10.1029/2008JB005873. Chu, Risheng, Don Helmberger, Daoyuan Sun, Jennifer M. Jackson, and Lupei Zhu (2010). Mushy Magma Beneath Yellowstone, Geophys. Res. Lett., 37, L01306, doi:10.1029/2009GL041656. Konca, A. Ozgun, S. Leprince, J-P Avouac, and Don V. Helmberger (2010). Rupture Process of the 1999 MW 7.1 Duzce Earthquake from Joint Analysis of SPOT, GPS, InSAR, Strong-Motion, and Teleseismic Data: A Supershear Rupture with Variable Rupture Velocity, Bull. Seismol. Soc. Am., 100, No. 1, 267-288. Luo, Yan, Y. Tan, S. Wei, D. Helmberger, Z. Zhan, S. Ni, E. Hauksson, and Y. Chen (2010). Source Mechanism and Rupture Directivity of the Mw 4.6 May 18, 2009 Inglewood, California Earthquake, BSSA, Short Note, 100, 3269-3277. Ni, Sidao, D. V. Helmberger, and A. Pitarka (2010). Rapid Source Estimation from global calibrated paths, Seismol. Res. Letts., 81, No. 3, 498-504. Sun, Daoyuan, D. V. Helmberger, and M. Gurnis (2010). A Narrow, Mid-Mantle Plume below Southern Africa, Geophys. Res. Lett., 37, L09302, doi:10.1029/2009GL 042339..

14 Tan, Ying and Don Helmberger (2010). Rupture Directivity Characteristics of the 2003 Big Bear Sequence, Bull. Seismol. Soc. Am., 100, No. 3, 1089-1106. Tan, Ying, Teh-Ru Alex Song, Shengji Wei, and Don Helmberger (2010). Surface Wave Path Corrections and Source Inversions in Southern California, Bull. Seismol. Soc. Am., 100 (6), 2891-2904. Sun, Daoyuan and D. V. Helmberger (2011). Upper-mantle structures beneath USArray derived from waveform complexity, Geophys. J. Int., 184 (1), 416-438, doi:10.1111/j.1365-246X.2010.04847.x. Liu, Lijun, Ying Tan, Daoyuan Sun, Min Chen, and Don Helmberger (2011). Trans- Pacific whole mantle structure, J. Geophys. Res., 116, B04306, doi:10.1029/ 2010JB007907. Simons, M., A. Sladen, S. E. Owen, S. E. Minson, F. Ortega, F. Jiang, L. Meng, J.-P. Ampuero, S. Wei, R. Chu, D. V. Helmberger, H. Kanamori, E. Hetland, A. W. Moore and F. H. Webb (2011). The 201l magnitude 9.0 Tohoku-Oki earthquake: Mosaicking the megathrust from seconds to centuries, Science, 332, doi:10.1126/Science, 1206731. Zhan, Zhongwen, S. Wei, S. Ni, and Don Helmberger (2011). Earthquake Centroid Locations Using Calibration from Ambient Seismic Noise, Short Note, BSSA, 101, No. 3, 1438-1445. Chu, Risheng, S. Wei, Don V. Helmberger, Z. Zhan, L. Zhu and H. Kanamori (2012). Initiation of the great Mw 9.0 Tohoku-Oki earthquake, Earth Planet. Sci. Lett., 308(3), 277-283. Chu, Risheng, B. Schmandt, and Don Helmberger (2012). Juan de Fuca Subduction Zone from a Mixture of Tomography and Waveform Modeling, J. Geophys. Res., 117, B03304, doi:10.1029/2012JB009146. Chu, Risheng, B. Schmandt, and Don V. Helmberger (2012), Upper-mantle P-velocity structure beneath the Midwestern United States derived from triplicated waveforms, Geochem. Geophys., Geosys., 13, No. 1, Q0AK04, doi:10.1029/2011GC003818. Chu, Risheng, D. V. Helmberger, and M. Gurnis (2012), Upper Mantle Surprises derived from the recent Virginia Earthquake waveform data, Earth Planet. Sci. Lett., doi:10.1016/j.epsl.2012.10.023. Wei, Shengji, E. Fielding, S. Leprince, A. Sladen, J-P Avouac, D. V. Helmberger, E. Hauksson, R. Chu, M. Simons, K. Hudnut, T. Herring, and R. Briggs (2012). Superficial simplicity of the 2010 El Mayor-Cucapah earthquake of Baja California in Mexico, Nature Geoscience, 4(9),615-618. Wei, Shengji, Zhongwen Zhan, Ying Tan, Sidao Ni, and Don Helmberger (2012). Locating Earthquakes with Surface Waves and Centroid Moment Tensor Estimation, JGR, 117, B04309, doi:10.1029/2011JB008501. Wei, Shengji, R. Graves, D. V. Helmberger, J-P Avouac, and J. Jiang (2012). Sources of shaking and flooding during the Tohoku-Oki Earthquake: A mixture of rupture styles, Earth and Planetary Sci. Lett., 333-334, 91-100. Zhan, Zhongwen, S. Ni, Don V. Helmberger, and Robert W. Clayton (2012). Retrieval of body waves from ambient seismic noise, Geophys. J. Int.. 182, 408-420. Zhan, Zhongwen, D. V. Helmberger, M. Simons, H. Kanamori, W. Wu, N. Cubas, Z. Duputel, R. Chu, V. C. Tsai, J.-P. Avouac, K. Hudnut, S. Ni, E. Hetland, and F. Ortega Culaciati (2012). Anomalously steep dips of earthquakes in the 2011

15 Tohoku-Oki source region and possible explanations, Earth Planet. Sci. Lett., 353, 121-133. Chu, Risheng, W. Leng, D. V. Helmberger, and M. Gurnis (2013). Hidden hotspot track beneath Eastern United States, Nature Geoscience, doi: 10.1038/ngeo1949 Chu, Risheng and D. V. Helmberger (2013). Source Parameters of the Shallow 2012 Brawley Earthquake, Imperial Valley, Bull. Seismol. Soc. Am., Short Note, 103, No. 2A, 1141-1147. Chu, Risheng and D. V. Helmberger (2013). Source Parameters of the Shallow 2012 Brawley Earthquake, Imperial Valley, Bull. Seismol. Soc. Am., Short Note, 103, No. 2A, 1141-1147. Sun, Daoyuan, Don V. Helmberger, Jennifer M. Jackson, Robert W. Clayton and Dan J. Bower (2013). Rolling hills on the Core-Mantle Boundary, Earth and Planetary Science Letters, 361, 333-342, doi:10.1016/j.epsl.2012.10.027. Wei, Shengji, Don Helmberger, Susan Owen, Rob Graves, K. Hudnut, and Eric Fielding (2013). Complementary slip distributions of the largest earthquakes in the 2012 Brawley Swarm, Imperial Valley, California, Geophys. Res. Lett., 40, 847-852, doi:10.1002/grl.50259. Wei, Shengji, Don Helmberger, and Jean-Philippe Avouac (2013). Modeling the 2012 Wharton Basin Earthquakes off-Sumatra: Complete Lithospheric Failure, J. Geophys. Res.: Solid Earth, 118, 1-18, doi:10.1002/jgrb.50267. Wei, Shengji, D. Helmberger, Z. Zhan, and R. Graves (2013). Rupture Complexity of the Mw 8.3 Sea of Okhotsk Earthquake: Rapid Triggering of Complementary Earthquakes, Geophys. Res. Letts., 40, 1-6, doi:10.1002/grl.50977. Avouac, Jean-Philippe, Francois Ayoub, Shengji Wei, Jean-Paul Ampuero, Lingsen Meng, Sebastien Leprince, Romain Jolivet, Zacharie Duputel, and Don Helmberger (2013). The 2013, Mw7.7 Balochistan Earthquake, seismic slip boosted on a misoriented fault, submitted to Earth and Planetary Sci. Letts. Chu, Risheng, S. Ni, A. Pitarka and Don V. Helmberger (2013). Inversion of source parameters for moderate earthquakes using short-period teleseismic P waves, Geophysics J. Int., in press. Chu, Risheng and D. V. Helmberger (2014). Lithospheric waveguide beneath the Midwestern United States; massive low-velocity zone in the lower crust, Geochem. Geophys, Geosys. 15, 1348-1362 Li, Dunzhu, Don Helmberger, Rob Clayton, and Daoyuan Sun (2014). Global synthetic seismograms using 2D finite-difference method, Geophys. J. Int. doi:10.1093/gji/ggu050 Zhan, Zhongwen, Don Helmberger, and Dunzhu Li (2014). Imaging subducted slab structure beneath the Sea of Okhotsk with teleseismic waveforms, Phys. Earth Planet In., 232, 30-35. 18. Zhan, Z., V. C. Tsai, J. Jackson, and D. Helmberger (2014). Ambient noise correlation on the Amery Ice Shelf, East Antarctica, Geophys. J. Int., 196, 1796-1802. Zhan, Z., H. Kanamori, V. C. Tsai, D. Helmberger, and S. Wei (2014). Rupture complexity of the 1994 Bolivia and 2013 Sea of Okhotsk deep earthquakes, Earth Planet. Sci. Lett., 385, 89-96. DOI:10.1016/j.epsl.2013.10.028 Lui, S. K. Y., D. Helmberger, S. Wei, Y. Huang and R.W. Graves (2015) Interrogation of the Megathrust Zone in the Tohoku-Oki Seismic Region by Waveform Complexity:

16 Intraslab Earthquake Rupture and Reactivation of Subducted Normal Faults, Pure and Applied Geophysics; DOI: 10.1007/s00024-015-1042-9 Wei, S., J.P. Avouac, K. W. Hudnut, A. Donnellan, J. W. Parker, R. W. Graves, D. Helmberger, E. Fielding, Z. Liu, F. Cappa, M. Eneva (2015) The 2012 Brawley swarm triggered by injection-induced aseismic slip, Earth and Plan. Sci. Lett. 07/2015; 422. DOI:10.1016/j.epsl.2015.03.054 Wei, S., S. Barbot, R. Graves, J.J. Lienkaemper, T. Wang, K. Hudnut, Y. Fu, and D. Helmberger (2015) The 2014 M-W 6.1 South Napa Earthquake: A Unilateral Rupture with Shallow Asperity and Rapid Afterslip, Seism. Res. Lett., 86(2A):2A. DOI:10.1785/0220140249

SCIENTIFIC COLLABORATORS, LAST 48 MONTHS: Risheng Chu, Vernon Cormier, Ed Garnero, Michael Gurnis, Jennifer Jackson, Meghan Miller, Jeroen Ritsema, Igor Sidorin, Xiaodong Song, Chandan Saikia, Thorne Lay, Jeroen Tromp, Lianxing Wen, Steve Grand, Teh-ru Alex Song, Ying Tan, and Lupei Zhu.

GRADUATE STUDENTS, AND POST-DOCS SUPERVISED: Supervised students with both theoretical and observational efforts, but referenced by relationship to structure (A) vs. source modeling (B): A. L. J. Burdick, X. Ding, E. J. Garnero, J. Given, S. P. Grand, R. W. Graves, T.-L. Hong, T. Lay, T. Melbourne, Sidao Ni, J. A. Rial, B. Savage, P. Scott, Igor Sidorin, Tehru Alex Song, Xiaodong Song, Daoyuan Sun, L. Wen, Y. Tan. B. A. L. Bent, D. S. Dreger, J. E. Ebel, S. Hartzell, T. H. Heaton, P. Ho-Liu, Chen Ji, A. Ozgun Konca, L. E. Jones, C. A. Langston, H.-L. Liu, G. R. Mellman, L. J. Ruff, C. W. Scrivner, Xi J. Song, R. J. Stead, , J. E. Vidale, D. J. Wald, T. C. Wallace, S. Wei, B. B. Woods, L.-S Zhao, L. Zhu. Z. Zhan.

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