Colin A. Zelt

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Research Statement

My research interests include the development, assessment and application of seismic modeling and inversion techniques for studies of the near-surface (upper 100m), basins and crust. More specifically, this includes 2D and 3D traveltime inversion and tomography methods, including a newly developed frequency-dependent form of tomography that is applicable to controlled-source (picked) traveltime data. My students and I are also applying 2D full waveform tomography methods for P-wave and S-wave data.

We develop models of the seismic properties of the subsurface in two- and three-dimensions using artificial sources, and receiver arrays that are a few tens of meters to a few hundred kilometers long, both on land and at sea. In most cases this involves the interpretation of seismic refraction/wide-angle reflection data. We often interpret these models along with existing information that may include surface geology, well data, or results from seismic reflection, earthquake or gravity studies. Recently, my focus has turned to the shallow subsurface (upper tens of meters) for environmental, engineering and risk assessment studies.

I sometimes get involved in acquiring land and marine seismic data with colleagues at Rice and at other academic and government institutions. I also study methodological aspects of traveltime and waveform tomography and inversion. Finally, I am also interested in, and teach an introductory course in, geophysical inverse theory.

Publications

Park, J., J.K. Morgan, C. A. Zelt and P. G. Okubo, Volcano-tectonic implications of 3-D velocity structures derived from active- and passive-source tomography of the Island of Hawaii, J. Geophys. Res., submitted, 2008

Jaiswal, P. and C. A. Zelt, Unified Imaging of Multichannel Seismic Data: Combining Traveltime Inversion and Pre-Stack Depth Migration, Geophysics, 73, VE269-VE280, 2008

Fradelizio, G. L., A. Levander, and C. A. Zelt, Three-dimensional seismic-reflection imaging of a shallow buried paleochannel, Geophysics, 73, B85-B98, 2008

Jaiswal, P., C. A. Zelt and R. Dasgupta, Seismic Imaging of the Naga Thrust using multiscale waveform inversion, Geophysics, in press, 2008

Schmelzbach, C., C. A. Zelt, C. Juhlin, and R. Carbonell, P- and Sv -velocity structure of the South Portuguese Zone fold-and-thrust belt, SW Iberia, from traveltime tomography, Geophys. J. Int., 175, 689-712, 2008

Clark, S. A., A. Levander, M. B. Magnani, and C. A. Zelt,, Integrating a regional wide-angle velocity model with seismic reflection data and structural interpretations of the Caribbean-South American plate boundary at 64W, Tectonics, in press, 2008

Clark, S. A., M. Sobiesiak, C. A. Zelt, M. B. Magnani, M. S. Miller, M. J. Bezada and A. Levander, Identification and tectonic implications of a tear in the South American plate at the southern end of the Lesser Antilles, Geochem. Geophys. Geosyst., 9, Q11004, doi:10.1029/2008GC002084, 2008

Schmitz, M., J. Avila, M. Bezada, E. Vieira, M. Yáñez, A. Levander, C. A. Zelt, M. I. Jácome, M. B. Magnani, and the BOLIVAR active seismic working group, Crustal thickness variations in Venezuela from deep seismic observations, Tectonophysics, 459, 14-26, 2008

Magnani, M. B., C. A. Zelt, A. Levander and M. Schmitz, Crustal structure of the South America-Caribbean plate boundary at 67W from controlled-source seismic data, J. Geopys. Res., in press, 2008

Clark, S. A., C. A. Zelt, M. B. Magnani, and A. Levander, Characterizing the Caribbean-South American plate boundary at 64W using wide-angle seismic data, J. Geopys. Res., 113, B07401, doi:10.1029/2007JB005329, 2008

Jaiswal, P., C. A. Zelt, A. W. Bally, and R. Dasgupta, 2-D traveltime and waveform inversion for improved seismic imaging: Naga Thrust and Fold Best, India, Geophys. J. Int., 173, 642-658, 2008

Levander, A., C. A. Zelt, and W. W. Symes, Controlled-Source Seismology: A Primer, Treatise on Geophysics, Elsevier, Eds. B. Romanowicz and A. Dziewonski, in press, 2007.

Gao, F., A. Levander, R. G. Pratt, C. A. Zelt and G.-L. Fradelizio "Waveform Tomography at a Ground Water Contamination Site: VSP-Surface Data set." Geophysics, 71 (2006): H1-H11.

Jaiswal, P., C. A. Zelt and I. A. Pecher "Seismic Characterization of a Gas Hydrate System in the Gulf of Mexico Using Wide-Aperture Data." Geophysical Journal International, 165 (2006): 108-120.

Zelt, C. A., A. Azara and A. Levander "3D seismic refraction traveltime tomography at a groundwater contamination site." Geophysics, 71 (2006): H67-H78.

Zelt, C.A, R.M. Ellis, and B.C. Zelt "3-D structure across the Tintina strike-slip fault, northern Canadian Cordillera, from seismic refraction and reflection tomography." Geophysical Journal International, 167 (2006): 1292-1308.

Levander, A., C. A. Zelt, and M. B. Magnani, Crust and upper mantle velocity structure of the Southern Rocky Mountains from the Jemez Lineament to the Cheyenne belt, in The Rocky Mountain Region: An Evolving Lithosphere, Geophysical Monograph Series 154, American Geophysical Union, Eds. K. E. Karlstrom and R. G. Keller, 293-308, 2005.

Hole, J. A., C. A. Zelt and R. G. Pratt, Advances in Controlled-Source Seismic Imaging, EOS, 86, 177, 181, 2005

K. Ramachandran, S. E. Dosso, C. A. Zelt, G. D. Spence, R. D. Hyndman,and T. M. Brocher "Upper crustal structure of southwestern British Columbia from the 1998 Seismic Hazards Investigation in Puget Sound." JOURNAL OF GEOPHYSICAL RESEARCH, 109 (2004): B09303, doi:10.1029/2003JB002826.

Zelt, C. A., K. Sain, J. V. Naumenko and D. S. Sawyer "Assessment of crustal velocity models using seismic refraction and reflection tomography." Geophysical Journal International, 153 (2003): 609-626.

J. V. Morgan, G. L. Christeson, Zelt, C. "Testing the resolution of a 3D velocity tomogram across the Chicxulub crater." Tectonophysics, 355 (2002): 215-226.

Kalachand Sain, Zelt, C., P. R. Reddy "Imaging of subvolcanic Mesozoics in the Saurashtra Peninsula of India using travel time inversion of wide-angle seismic data." Geophysical Journal International, 150 (2002): 820-826.

Zelt, B. C., R. M. Ellis, C. A. Zelt, R. D. Hyndman, C. Lowe, G. D. Spence, and M. A. Fisher "Three-dimensional crustal velocity structure beneath the Strait of Georgia, British Columbia." Geophys. J. Int., 144 (2001): 695-712.

Hojka, A. M., C. A. Zelt, and E. R. Flueh "3-D seismic refraction tomography of ocean bottom hydrophone data recorded offshore Valparaiso, Chile." Zentralblatt fur Geologie und Palaeontologie,, Part 1 (2000): 679-693.

Zelt, C. A. "Modelling strategies and model assessment for wide-angle seismic traveltime data." Geophys. J. Int., 139 (1999): 183-204.

Condi, F. J., C. A. Zelt, D. S. Sawyer, and G. J. Hirasaki "Gravity inversion for rifted margin deep structure using extension and isostatic constraints." Geophys. J. Int., 138 (1999): 435-446.

Zelt, C. A., A. M. Hojka, E. R. Flueh, and K. D. McIntosh "3D simultaneous seismic refraction and reflection tomography of wide-angle data from the central Chilean margin." Geophysical Research Letters, 26 (1999): 2577-2580.

Zelt, C. A. and B. C. Zelt "Study of out-of-plane effects in the inversion of refraction/wide-angle reflection traveltimes." Tectonophysics, 286 (1998): 209-221.

Zelt, B. C., M. Talwani and C. A. Zelt "Prestack depth migration of dense wide-angle seismic data." Tectonophysics, 286 (1998): 193-208.

Zelt, C. A. "Lateral velocity resolution from 3-D seismic refraction data." Geophys. J. Int., 135 (1998): 1101-1112.

Bradford, J. H., D. S. Sawyer, C. A. Zelt and J. S. Oldow "Imaging a shallow aquifer in complex, glacial sediments using seismic reflection profiling with DMO processing." Geophysics, 63 (1998): 1248-1256.

Zelt, C. A. and P. J. Barton "3D seismic refraction tomography: A comparison of two methods applied to data from the Faeroe Basin." J. Geophys. Res., 103 (1998): 7187-7210.

Presentations

Thesis co-advisor. "CRUSTAL STRUCTURE ACROSS THE CARIBBEAN SOUTH AMERICA PLATE BOUNDARY AT 70°W: RESULTS OF THE BOLIVAR PROJECT." Backbone of the Americas–Patagonia to Alaska, GSA, Mendoza, Argentina. (2006) With GUEDEZ, M. C., M. B. MAGNANI, and A. LEVANDER.

"SEISMIC STRUCTURE OF THE LEEWARD ANTILLES ARC AND GROWTH OF THE SOUTH AMERICAN CONTINENT." Backbone of the Americas–Patagonia to Alaska, GSA, Mendoza, Argentina. (2006) With AROGUNMATI, A., and A. LEVANDER.

"ISLAND ARC ACCRETION BY OBLIQUE COLLISION: THE RESULTS OF THE BOLIVAR PROJECT ALONG THE SE CARIBBEAN PLATE BOUNDARY." Deep Seismic Profiling of the Continents and their Margins, Hayama, Japan. (2006) With M. B. Magnani, M. Guedez, S. Clark, A. Arogunmati, F. Niu, A. Levander and G. Christeson.

Thesis Advisor. "Imaging Improvements Through Traveltime and Waveform Inversion: Naga Thrust Belt, North East India." EAGE Annual Meeting, Vienna, Austria. (2006) With P. Jaiswal.

Thesis committee. "Using elastic wave seismic data to image an ultra-shallow buried paleo-channe." SEG Hydrogeophysics Workshop, Vancouver, Canada. (2006) With G. L. Fradelizio, A. Levander.

"Imaging the SE Caribbean Accretionary Boundary: Results from the BOLIVAR Seismic Reflection and Refraction data at 65W and 67W." Origin of the Caribbean Plate, Geological Society of London, Sigüenza, Spain. (2006) With M.B, Magnani, and A. Levander.

"Plumbing the Depths of the Caribbean-South American Arc-Continent Collisional Zone Using Long Seismic Reflection and Refraction Transects." Origin of the Caribbean Plate, Geological Society of London, Sigüenza, Spain. (2006) With P. Mann, B. Magnani, A. Escalona, G. Christeson, A. Levander, S. Clark, M. Guedez, D. Sawyer, and M. Schmitz.

Thesis co-advisor. "BOLIVAR: 3-D Seismic Structure of the Leeward Antilles Arc From Seismic Refraction and Reflection Tomography." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Arogunmati, A. T., A. Levander.

Thesis committee. "Using Elastic Wave Seismic Data to Image an Ultra-shallow Buried Paleo- channel." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Fradelizio, G., A. Levander.

Thesis co-advisor. "New evidence for deep magma migration in Hawaii: Seismic tomography of Kilauea and Loihi volcanoes." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Park, J., J. K. Morgan, P. G. Okubo.

Thesis co-advisor. "Bolivar: Crustal Structure of the Caribbean-South America plate boundary at 70W." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Guedez, M. C., M. B. Magnani, and A. Levander.

Thesis committee. "Crustal Thickness Variations Along the Southeastern Caribbean Plate Boundary From Teleseismic and Active Source Seismic Data." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Bezada, M.J., F. Niu, T.K. Baldwin, G. Pavlis, F. Vernon, H. Rendon, M. Schmitz, A. Levander.

"Exhumation of high-pressure Metamorphic rocks along the coast of Venezuela: Insights from BOLIVAR Seismic Reflection and Refraction Data." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Magnani, M., P. Mann, A. Levander, H. Ave Lallemant.

Thesis committee. "Using elastic wave seismic data to image an ultra-shallow buried paleo-channel." Society of Exploration Geophysicists, New Orleans, LA. (2006) With Fradelizio, and A. Levander.

"An iterative approach for geophysical diffraction tomography: Implication for true amplitude migration." Society of Exploration Geophysicists, New Orleans, LA. (2006) With Gao, F., and A. Levander.

"BOLIVAR & GEODINOS: INVESTIGATING ISLAND ARC ACCRETION ALONG THE SOUTHEASTERN CARIBBEAN PLATE BOUNDARY." Backbone of the Americas–Patagonia to Alaska, GSA, Mendoza, Argentina. (2006) With A. Levander.

"BOLIVAR: INVESTIGATING ISLAND ARC ACCRETION ALONG THE SOUTHEASTERN CARIBBEAN PLATE BOUNDARY." Geological Society of America, Philadelphia, PA. (2006) With LEVANDER, A., M. SCHMITZ, P. MANN, G. CHRISTESON, J. WRIGHT, H. AVE LALLEMANT, C. ZELT, J. PINDELL, G. PAVLIS, and F. NIU.

"FINITE-FREQUENCY TRAVELTIME TOMOGRAPHY FOR ACTIVE-SOURCE SEISMIC DATA." Deep Seismic Profiling of the Continents and their Margins, Hayama, Japan. (2006)

"BOLIVAR & GEODINOS: INVESTIGATING ISLAND ARC ACCRETION ALONG THE SOUTHEASTERN CARIBBEAN PLATE BOUNDARY." IRIS Workshop, Tucson, AZ. (2006) With LEVANDER, A., M. SCHMITZ and BOLIVAR and GEODINOS Working Groups.

"Plumbing the Depths of the Caribbean-South American Arc-Continent Collisional Zone Using Long Seismic Reflection and Refraction Transects." AAPG Annual Meeting, Houston, TX. (2006) With P. Mann, G. Christeson, A. Escalona, A. Levander, B. Magnani, D. Sawyer, and M. Schmitz.

"First-order, regional-scale geophysical constraints on the structure, stratigraphy, and tectonics of the South America-Caribbean arc-continent collision." Origin of the Caribbean Plate, Geological Society of London, Sigüenza, Spain. (2006) With P. Mann, A. Escalona, B. Magnani, G. Christeson, A. Levander, S. Clark, M. Guedez, D. Sawyer, and M. Schmitz.

"Tearing the lithosphere: Diachronous slab detachment along the Venezuelan margin from BOLIVAR seismic data." AGU Annual Fall Meeting, San Francisco, CA. (2006) With Clark, S., F. Niu, A. Levander.

"Finite-Frequency Traveltime Tomography for Active-Source Seismic Data." AGU Annual Fall Meeting, San Francisco, CA. (2006)

Theses

Frank Condi, Doctoral. "Estimating subsurface structure through gravity and gravity gradiometry inversion." (1999).(Thesis or Dissertation Director)

Julia V. Naumenko, Masters. "Seismic traveltime inversion of wide-angle data for strongly-varying structure: Central Chilean margin and the subducting Juan Fernandez Rdige." (2001).(Thesis or Dissertation Director)

Diana Dana, MA. "High resolution seismic investigations for mining and environmental studies." (2001).(Thesis or Dissertation Director)

Priyank Jaiswal, MA. "Seismic Characterization of a Gas Hydrate System in the Gulf of Mexico - A Novel Approach for Evaluating High-Resolution Wide-Aperture Data." (2002).(Thesis or Dissertation Director)

Aron Azaria, Masters. "Three-dimensional traveltime tomography at a shallow groundwater contamination site." (2003).(Thesis or Dissertation Director)

Adeyemi Arogunmati, Master of Science. "3-D Seismic Structure of the Leeward Antilles Arc from seismic refraction and reflection tomography." (2006).(Thesis or Dissertation Director)

Maria C. Guedez, Master of Science. "Crustal Structure across the Caribbean-South American Plate Boundary at 70W - Results from seismic refraction and reflection data." (2007).(Thesis or Dissertation Director)

Jaewoo Park, PhD. "3D velocity and gravity structure of the south flank of Kilauea Volcano, Hawaii." (2008).(Co-Director)

Priyank Jaiswal, PhD. "Waveform and traveltime inversion for improved seismic imaging." (2008).(Thesis or Dissertation Director)