IJG  Vol.2 No.3 , August 2011
Clusters of Moderate Size Earthquakes along Main Central Thrust (MCT) in Himalaya
ABSTRACT
The Main Central Thrust (MCT) in Himalaya is seismically active in segments. In recent times, strain release within these active segments produce five spatial clusters (A to E; Figure 1). The seismicity within the cluster zones occurs in two depth bands; corresponding to the base of upper and lower crust. Depth sections across the clusters illustrate gently dipping subducted Indian Plate, overriding Tibetan Plate and compressed Sedimentary Wedge in between, with mid crustal ramping of MCT. Several presumptions / hypotheses have been put forward to decipher the causes of clustering along MCT. These are segmental activation of MCT, cross fault interactions, zones of arc parallel and arc perpendicular compressions, pore pressure perturbations, low heat flow zones etc. But these hypotheses need to be evaluated in the future after more ground level data are available. The maximum size of seismic threat that MCT can produce is inferred to be around Mw 7.0 in those clusters.

Cite this paper
nullB. Mukhopadhyay, "Clusters of Moderate Size Earthquakes along Main Central Thrust (MCT) in Himalaya," International Journal of Geosciences, Vol. 2 No. 3, 2011, pp. 318-325. doi: 10.4236/ijg.2011.23034.
References
[1]   K. S. Valdiya, “Himalayan Transverse Faults and Their Parallelism with subsurface Structures of North Indian Plains,” Tectonophysics, Vol. 32, No. 3-4, 1976, pp. 352-386. doi:10.1016/0040-1951(76)90069-X

[2]   P. Le Fort, “Metamorphism and Magmatism during the Himalayan Collision,” In: M. P. Coward, A. C. Ries, Eds., Collision Tectonics, Geol. Soc. Spec. Publ., Vol. 19, 1986, pp. 159-172.

[3]   L. Bollinger, P. Henry and J.P. Avouac, “Mountain Building in the Nepal Himalaya: Thermal and Kinematic Model,” Earth and Planetary Science Letters, Vol. 244, No. 1-2, 2006, pp. 58-71. doi:10.1016/j.epsl.2006.01.045

[4]   R. M. Manickavasagam, A. K. Jain, S. Singh, A. Asokan, A. Macfarlane, R. Sorkhabi and J. Quade, “Metamorphic Evolution of the Northwest Himalaya, India; Pressure– Temperature Data, Inverted Metamorphism, and Exhumation in the Kashmir, Himachal, and Garhwal Himalayas Himalaya and Tibet; Mountain Roots to Mountain Tops,” Special Paper—Geological Society of America, Vol. 328, 1999, pp. 179-198.

[5]   P. G. Decelles, G. E. Gehrels, J. Quade, B. Lareau and M. Spurlin, “Tectonic Implications of U–Pb Zircon Ages of the Himalayan Orogenic Belt in Nepal”, Science, Vol. 288, No. 5465, 2000, pp. 497-499. doi:10.1126/science.288.5465.497

[6]   D. Marquer, H. S. Chawla and N. Challandes, “Pre-Alpine High Grade Metamorphism in High Himalaya Crystalline Sequences: Evidences from Lower Palaeozoic Kinnar Kailas Granite and Surrounding Rocks in the Sutlej Valley (Himachal Pradesch, India),” Eclogae Geologicae Helvetiae, Vol. 93, 2000, pp. 207-220.

[7]   D. Schelling and K. Arita, “Thrust Tectonics, Crustal Shortening, and the Structure of the Far-Eastern Nepal Himalaya”, Tectonics, Vol. 10, No. 5, 1991, pp. 851-862. doi:10.1029/91TC01011

[8]   P. Srivastava and G. Mitra, “Thrust Geometries and Deep Structure of the Outer and Lesser Himalaya, Kumaon and Garhwal (India): Implications for Evolution of the Himalayan Fold and Thrust Belt,” Tectonics, Vol. 13, No. 1, 1994, pp. 89-109. doi:10.1029/93TC01130

[9]   O. N. Pearson and P. G. Decelles, “Structural Geology and regional Tectonic Significance of the Ramgarh Thrust, Himalayan Fold-Thrust Belt of Nepal”, Tectonics, Vol. 24, 2005, p. TC4008. doi:10.1029/2003TC001617

[10]   B. Mukhopadhyay, A. Acharyya and S. Dasgupta, “Potential Source Zones for Himalayan Earthquake: Constraints from Spatial-Temporal Clusters”, Natural Hazards, Vol 57, No. 2, 2011, pp. 369-383. doi:10.1007/s11069-010-9618-2

[11]   L. Seeber, J. G. Armbruster and R. Quittmeyer, “Seismicity and Continental Subduction in the Himalayan Arc”, In: H. K. Gupta and F. M. Delany, Eds., Zagros, Hindu Kush, Himalaya Geodynamic Evolution, American Geographical Union, Washington, DC—Geodynamics Series, Vol. 4, 1981, pp. 215-242.

[12]   J. F. Ni and M. Barazangi, “Seismotectonics of the Himalayan Collision Zone: Geometry of the Underthrusting Indian Plate beneath the Himalaya”, Journal of Geophysical Research, Vol. 89, No. B2, 1984, pp. 1147-1163. doi:10.1029/JB089iB02p01147

[13]   H. Lyon-Caen and P. Molnar, “Gravity Anomalies and the Structure of Western Tibet and Southern Tarim Basin,” Geophysics Research Letter, Vol. 11, No. 12, 1983, pp. 1251-1254. doi:10.1029/GL011i012p01251

[14]   J. Lavé and J.P. Avouac, “Active Folding of Fluvial Terraces across the Siwalik Hills (Himalaya of Central Nepal)”, Journal of Geophysical Research, Vol. 105, No. B3, 2000, pp. 5735-5770. doi:10.1029/1999JB900292

[15]   R. Cattin and J.P. Avouac, “Modeling Mountain Building and the Seismic Cycle in the Himalaya of Nepal”, Journal of Geophysical Research, Vol. 105, No. B6, 2000, pp. 13389-13407. doi:10.1029/2000JB900032

[16]   W. Zhao, K. D. Nelson, et al., “Deep seismic reflection evidence for continental underthrusting beneath southern Tibet”, Nature, Vol. 366, 1993, pp. 557-559. doi:10.1038/366557a0

[17]   M. Mukul, “Himalayan Deformation: Insights from Darjiling-Sikkim-Tibet (DaSiT) Wedge”, Journal of Asian Earth Sciences, Vol. 39, No. 6, 2010, pp. 645-657. doi:10.1016/j.jseaes.2010.04.029

[18]   K. Arita, “Origin of the inverted metamorphism of the Lower Himalaya, Central Nepal”, Tectonophysics, Vol. 95, No. 1-2, 1983, pp. 43-60. doi:10.1016/0040-1951(83)90258-5

[19]   S. M. Naqvi, “Geology and Evolution of the Indian Plate: from Hadean to Holocene”, Capital Publishing Company, New Delhi, 2005, p. 450.

[20]   P. Copeland, T. M. Harrison, K. V. Hodges, P. Maruejol, P. Lefort and A. Pecher, “An Early Pliocene Thermal Disturbance of Main Central Thrust, Central Nepal: Implication for Himalayan Tectonics,” Journal of Geophysical Research, Vol. 96, No. B5, 1991, pp. 8475-8500. doi:10.1029/91JB00178

[21]   C. Groppo, D. Rubatto, F. Rolfo and B. Lombardo, “Early Oligocene Partial Melting in the Main Central Thrust Zone (Arun Valley, Eastern Nepal Himalaya),” Lithos, Vol. 118, No. 3-4, 2010, pp. 287-301. doi:10.1016/j.lithos.2010.05.003

[22]   E. J. Catlos, C. S. Dubey, R. A. Marston and M. T. Harrison, “Geochronologic Constraints across the Main Central Thrust Shear Zone, Bhagirathi River (NW India): Implications for Himalayan Tectonics,” GSA Special Papers, Vol. 419, No. 4, 2007, pp. 135-151.

[23]   M. S. Hubbard and T. M. Harrison, “40Ar/39Ar Age Con- Straints on Deformation and Metamorphism in the Main Central Thrust Zone and Tibetan Slab, Eastern Nepal Himalaya”, Tectonics, Vol. 8, No. 4, 1989, pp. 865-880. doi:10.1029/TC008i004p00865

[24]   T.M. Harrison, F.J. Ryerson, P. Le Fort, A. Yin, O.M. Lovera, and E.J. Catlos, “A Late Miocene–Pliocene Origin for the Central Himalayan Inverted Metamorphism,” Earth Planet Science Letter, Vol. 146, No. 1-2, 1997, pp. E1-E8. doi:10.1016/S0012-821X(96)00215-4

[25]   K. V. Hodges, C. Wobus, K. Ruhl, T. Schildgen and K. Whipple, “Quaternary Deformation, River Steepening, and Heavy Precipitation at the Front of the Higher Himalayan Ranges,” Earth Planet Science Letter, Vol. 220, No. 3-4, 2004, pp. 379-389. doi:10.1016/S0012-821X(04)00063-9

[26]   K. S. Valdiya, “Dynamic Himalaya,” JNCASR, University Press (India) Limited, 2001, p. 178.

[27]   R. Bilham, K. Larson, J. Freymuller et al., “GPS measurements of the present day convergence across the Nepal Himalaya,” Nature, Vol. 386, 1997, pp. 61-63. doi:10.1038/386061a0

[28]   S. Dasgupta, P. Pande, D. Ganguly, Z. Iqbal, K. Sanyal, N. V. Venkatraman, S. Dasgupta, B. Sural, L. Harendra- nath, S. Mazumdar, S. Sanyal, A. Roy, L. K. Das, P. S. Misra and H. Gupta, “Seismotectonic Atlas of India and Its Environs,” Geological Survey of India, Kolkata, 2000, p. 86.

[29]   F. Cotton, M. Campillo, A. Deschamps and B. K. Rastogi, “Rupture History and Seismotectonics of the 1991 Uttarkashi, Himalaya Earthquake,” Tectonophysics, Vol. 258, No. 1-4, 1996, pp. 35-51. doi:10.1016/0040-1951(95)00154-9

[30]   P. Mandal, B. K. Rastogi and H. K. Gupta, “Recent Indian earthquakes,” Current Science, Vol. 79, No. 9, 2000, pp. 1334-1346.

[31]   P. Mandal, S. Padhy, B. K. Rastogi, H. V. S. Satyanara- yana, M. Kousalya, R. Vijayraghavan and A. Srinivasan, “Aftershock Activity and Frequency-Dependent Low Coda Qc in the Epicentral Region of the 1999 Chamoli Earthquake of Mw 6.4,” Pure and Applied Geophysics, Vol. 158, No. 9-10, 2001, pp. 1719-1735. doi:10.1007/PL00001241

[32]   J. R. Kayal, S. Ram, O. P. Singh, P. K. Chakraborty and G. Karunakar, “Aftershocks of the March 1999 Chamoli Earthquake and Seismotectonic Structure of the Garhwal Himalaya,” Bulletin of the Seismological Society of America, Vol. 93, No. 1, 2003, pp. 109-117. doi:10.1785/0119990139

[33]   D. J. Andrew, “Mechanics of Fault Junction,” Journal of Geophysical Research, Vol. 94, No. B7, 1989, pp. 9389-9397. doi:10.1029/JB094iB07p09389

[34]   L. Seeber and A. Pecher, “Strain Partitioning along the Himalayan Arc and Nanga Parbat Antiform,” Geology, Vol. 26, No. 9, 1998, pp. 791-794. doi:10.1130/0091-7613(1998)026<0791:SPATHA>2.3.CO;2

[35]   S. S. Rai, K. Priestley, V. K. Gaur, S. Mitra, M. P. Singh, and M. Searle, “Configuration of the Indian Moho beneath the NW Himalaya and Ladakh,” Geophysical Research Letters, Vol. 33, 2006, p. 15308. doi:10.1029/2006GL026076

[36]   A. F. Sheehan, T. Torre, G. Monsalve, V. Schulte- Pelkum, R. Bilham, F. Blume, R. Bendick, F. Wu, M. R. Pandey, S. Sapkota and S. Rajaure, “Earthquakes and Crustal Structure of the Himalaya from the Himalayan Nepal Tibet Seismic Experiment (HIMNT),” Journal of the Nepal Geological Society, Vol. 38, 2008, pp. 1-8.

[37]   P. M. Bhattacharya, S. Mukhopadhyay, R. K. Majumber and J. R. Kayal, “3-D Seismic Structure of Northeast India Region and Its Implication for Local and Regional Tectonics,” Journal of Asian Earth Sciences, Vol. 33, No. 1-2, 2008, pp. 25-41. doi:10.1016/j.jseaes.2007.10.020

 
 
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