Dr. Nong Wu (UW) Dr. Alan Jones(GSC), Prof. Chen Leshou (CUG), Prof. John Booker (UW), Prof. Wei Wenbo (CUG), Hu Jiande (CUG) Tan Handong (CUG)
outside Holiday Inn, Lhasa, just prior to commencement of 1995 MT field program (April 21st 1995)

MT Collaborators.....

INDEPTH Collaborators.....

  • Prof. Doug Nelson, Syracuse University (INDEPTH Project Leader)
  • Prof. Larry Brown, Cornell University
  • Prof. Simon Klemperer, Stanford University
  • Prof. Jim Ni, New Mexico State University


Phase I: 1995

Using the GSC's 16 LIMS and UW's 5 LIMS-clones (LRMTs built by Phoenix Geophysics), a long period MT survey was carried out in April to July along three main transects. For a plot of the sites on the topography of Asia please press here (Warning: the gif file is 150 Kb in size). For a location map of the sites showing the Zangbo suture and Lhasa, press here. For a geology map with the MT sites, press here.

Phase II (part of INDEPTH-III): 1998

In July and August 1998 Long Period magnetotelluric (MT) data were collected as part of the INDEPTH-III survey in Central Tibet. Long period MT data were collected at 26 sites on a 400 km profile extending from Nam Tso to Longwei Tso with the goal of imaging crustal and mantle structure. Broadband MT data were also collected to image shallow structure by the China University of Geosciences. In this paper we will present initial results based on the long period data, since the broadband and long period data have yet to be merged. Preliminary inversions of the long period MT data show the following features.
(1) In the south of the profile a strong conductor is observed at a depth of 15 km. This is at a similar depth to the conductor observed beneath the Yangbaijin graben during INDEPTH-II in 1995. This conductor terminates 50 km north of the Bangong suture.
(2) Further north, where the shallow conductor is absent, a deeper conductor is imaged at a depth of 50-60 km. This conductor continues to the northern end of the profile and is at the same depth as the low velocity zone imaged by seismic observations. It may represent the asthenosphere beneath a 50-60 km crust.

Published MT Papers.....


Published INDEPTH Papers.....

  • Alsdorf, D., Noise Reduction in Seismic Data Using Fourier Correlation Coefficient Filtering, (in final review Geophysics, 1996).
  • Alsdorf, D., L. D. Brown, and K. D. Nelson, Possible Upper Mantle Reflection Fabric on Seismic Profiles from the Tethyan Himalaya: Identification and Tectonic Interpretation, (Journal of Geophysical Research, accepted July 1996).
  • Brown, L. D., W. Zhao, K. D. Nelson, M. L. Hauck, D. Alsdorf, A. Ross, M. Cogan, M. Clark, X. Liu, and J. Che, Crustal Deformation and Magmatism at the Southern Margin of Tibet from Multichannel Seismic Reflection Profiling during Project INDEPTH, (submitted to Science, 1996)
  • Clark, M., The Nyainqentanglha Shear Zone at Depth: Detachment Faulting in Southern Tibet, Senior Thesis, Cornell University, 1995.
  • Cogan, M. J., INDEPTH Seismic Refraction Analysis of the Yadong- Gulu Rift: Evidence for a Fluid Middle Crust Beneath Southern Tibet, China, M.S. Thesis, Syracuse University, 1995.
  • Edwards, M. A., and T. M. Harrison, When did the Roof Collapse? Late Miocene N-S Extension in the High Himalaya Revealed by Th-Pb Monazite Dating of the Khula Kangri Granite, (submitted to Nature, 1996).
  • Edwards, M. A., C. Wu, W. S. F. Kidd, J. Li, Y. Yue, and K. D. Nelson, Two New Mylonites from Yadong-Gulu Rift System: Implications for East-West Extension in Southern Tibet, (to be submitted to Tectonics, 1996).
  • Edwards, M. A., W. S. F. Kidd, L. Jixiang, Y. Yongjun, and M. Clark, Multi-stage Development of the Southern Tibet Detachment System Near Khula Kangri. New Data from Gonto La, Tectonophysics, paper no. TECTO 4863, July 1996.
  • Hauck, M. L., K. D. Nelson, L. D. Brown, and A. Ross, Crustal Structure of the Central Himalaya: INDEPTH Reflection Profiles in Southern Tibet, (to be submitted to Tectonics, 1996).
  • Hauck, M. L., L. D. Brown, K. D. Nelson, J. T. Kuo, A. Calvert, W. Zhao, J. Che, and J. Guo, INDEPTH-I Case Study: The First Deep Seismic-reflection Profile in Tibet and the Himalayas, (submitted to Geophysics, 1996).
  • Kuo, J. T., T. Morgan, K. D. Nelson, L. D. Brown, W. J. Zhao, M. L. Hauck, Y. C. Teng, and Y. F. Sun, Finite-element Modeling of Primary Geological Structures along the INDEPTH Profiles in Southern Tibet in Tentner, A.M., Ed., Proceedings of the 1996 Simulation Multiconference -- High Performance Computing '96: Society for Computer Simulation, 84-94.
  • Makovsky, Y.., S. L. Klemperer, L. Ratschbacher, J. Mechie, H. Steentoft, R. Meissner, M. Li, W. Zhao, F. Meng, and J. Guo, INDEPTH Wide-angle Profiling in Southern Tibet: Mid-crustal Reflector Truncating the India-Asia Suture and Magma beneath the Tibetan Rift System, (submitted to Science, 1996).
  • Makovsky, Y., S. L. Klemperer, L. Huang, D. Lu, and the Project INDEPTH Team (W. Zhao, X. Liu, J. Guo, M. Li, K. D. Nelson, C. Wu, L. D. Brown, M. L. Hauck, J. T. Kuo), Structural Elements of the Southern Tethyan Himalaya Crust from Wide-angle Seismic Data, Tectonics, accepted,1996.
  • Nelson, K.D., Wenjin Zhao, L.D. Brown, J. Kuo, J. Che, X. Liu, S.L. Klemperer, Y. Makovsky, R. Meissner, J. Mechie, R. Kind, F. Wenzel, J. Ni, J. Nabelek, L. Chen, H. Tan, W. Wei, A.G. Jones, J. Booker, M. Unsworth, W.S.F. Kidd, M. Hauck, D. Alsdorf, A. Ross, M. Cogan, C. Wu, E. Sandvol, M. Edwards, 1996
    Partially molten middle crust beneath southern Tibet: synthesis of Project INDEPTH results
    Science, 274, 1684-1688.
  • Ni, J., E. Sandvol, W. Zhao, R. Kind, J. Nabelek, M. Brunner, K. Wu, L. Zhao, J. Wu, A. Fabritius, C. Reese, and T. Hearn, INDEPTH-II Passive-source Experiment: Implications for Underthrusting of the Indian Continental Lithosphere beneath Southernmost Tibet, (submitted to Science, 1996).
  • Reese, C. C.and J. Ni, Attenuation of Coda Waves in Southern Tibet, (submitted to Geophysical Research Letters, 1996).
  • Ross, A., L. D. Brown, D. Alsdorf, K. D. Nelson, and W. Zhao, CMP Profiling Evidence for Magma beneath Southern Tibet, (to be submitted to Journal of Geophysical Research, 1996).
  • Sandvol, E., J. Ni, R. Kind, J. Nabelek, and W. Zhao, Shear-wave Splitting along the India-Asia Collisional Zone (Azimuthal Seismic Anisotropy beneath Eastern India-Asia Collision Zone), (to be submitted to Bulletin of the Seismological Society of America, 1996).
  • Wu, C., K. D. Nelson, Y. Yue, J. Li, W. S. F. Kidd, and M. A. Edwards, Yadong Cross-structure and South Tibet Detachment, Southern Yadong-Gulu Rift, Tibet, (to be submitted to Tectonics, 1996).
  • Wu, J., J. Ni, R. Hermann, and R. Kind, Mid-crustal Low Velocity Zone in Southern Tibetan Plateau: Evidence from Rayleigh Phase Velocities, (submitted to Geophysical Research Letters, 1996).
  • Zhao, L., J. Ni, E. Sandvol, and R. Kind, Shear-wave Velocity Structure along the INDEPTH-II Profile, (to be submitted to Journal of Geophysical Research, 1996).
  • Zhao, W., K. D. Nelson, and the Project INDEPTH Team (J. Che, J. Guo, D. Lu, C. Wu, X. Liu, L. D. Brown, M. L. Hauck, J. T. Kuo, S. L. Klemperer, Y. Makovsky), Deep Seismic-reflection Evidence for Continental Underthrusting beneath Southern Tibet, Nature, vol. 366, 557-559, 1993.