Study on Some Recent Earthquakes of Sikkim Himalayan Region and Construction of Suitable Seismic Model: A Mathematical Approach

Conference paper
Part of the Lecture Notes in Mechanical Engineering book series (LNME)


Sikkim Himalayan region lies between Nepal–India border in the west and the Bhutan Himalaya in the east. The region is known to be characterized by strike-slip motion on certain deep-rooted faults. In the past, the region has experienced several devastating earthquakes, namely April 25, 2015 Nepal earthquake (M: 7.8); September 18, 2011 Mangan (Sikkim) earthquake (M: 6.9); February 14, 2006 Sikkim earthquake (M: 5.3), and the like. The present study mainly focuses on few major shocks and their source mechanism to explain properly the process of tectonics. A numerically stable computational scheme, using method of eigenfunction expansion has been used in the study to compute surface response or theoretical seismogram in a layered vertically stratified media overlying a half-space. Simple dislocation source model has been considered. The transverse (SH) and vertical (P-SV) components of displacement field have been computed exactly as summed modes by propagator matrix approach using Runga–Kutta method of order 4. The present result has been compared with the observed seismograms. The overflow error appearing in the numerical computation has been prevented by approximating layer matrices suitably or using generalized R/T (Reflection and Transmission) coefficients. The numerical result has been represented here graphically. The study has an advantage to get an idea of real earth structure or seismic source model by an inverse iterative technique.


Sikkim earthquake Seismogram Eigen function Sum mode 

Mathematics Subject Classification




The work was supported financially by U.G.C., New Delhi, India under MRP (Sanction No. F PSW-200/15-16 (ERO)).


  1. 1.
    Mukul M (2010) First-order kinematics of wedge-scale active Himalayan deformation: insights from Darjiling–Sikkim–Tibet (DaSiT) wedge. J Asian Earth Sci 39:645–657. Scholar
  2. 2.
    Mukul M (2000) The geometry and kinematics of the main boundary thrust and related neotectonics in the Darjiling Himalayan foldand-thrust belt. West Bengal J Struct Geol 22(9):1261–1283. Scholar
  3. 3.
    Molnar P, Tapponnier P (1975) Cenozoic tectonics of Asia: effect of a continental collision. Science 489:419–426CrossRefGoogle Scholar
  4. 4.
    Bilham R, Ambraseys N (2005) Apparent Himalayan slip deficit from the summation of seismic moments for Himalayan earthquakes, 1500–2000. Curr Sci 88(10):1658–1663Google Scholar
  5. 5.
    Hodges KV (2000) Tectonics of the Himalaya and southern Tibet from two perspectives. Bull Geol Soc Am 112:324–350CrossRefGoogle Scholar
  6. 6.
    Ingate SF, Bock G, Kind R (1983) Synthesis of complete SH seismograms. Geophys J R Astron Soc 75:261–274. Scholar
  7. 7.
    Harkrider DG (1964) Surface waves in multilayered elastic media I. Rayleigh and Love waves from buried sources in a multi-layerd elastic half-space. Bull Seism Soc Am 54:627–679 (1964)Google Scholar
  8. 8.
    Kind R (1978) The reflectivity method for a buried source. J Geophys 44:603–612Google Scholar
  9. 9.
    Kind R (1979) Extensions of the reflectivity method. J Geophys 45:373–380Google Scholar
  10. 10.
    Kazi MH (1978) The Love wave scattering matrix for a continental margin. Geophys J R Astron Soc 52:25–44CrossRefGoogle Scholar
  11. 11.
    Herrmann RB (1979) SH-wave generation by dislocation sources—a numerical study. Bull Seismol Soc Am 69:1–15Google Scholar
  12. 12.
    Florsch N, Fah D, Suhadolc P, Panza GF (1991) Complete synthetic seismogram for high-frequency multimode SH-waves. PAGEOPH 136(4):529–560CrossRefGoogle Scholar
  13. 13.
    Apsel RJ, Luco JE (1983) On the Greens function for a layered half space, Part-II. Bull Seismol Soc Am 73:930–953Google Scholar
  14. 14.
    Kennett BLN, Kerry NJ (1979) Seismic waves in a stratified half space. Geophys J R Astron Soc 57:557–583. Scholar
  15. 15.
    Kennett BLN (1983) Seismic wave propagation in stratified media. Cambridge University PressGoogle Scholar
  16. 16.
    Takeuchi H, Saito M (1972) Seismic surface waves. In: BA Bolt (ed) Methods in computational physics, 11 edn. Academic Press, New YorkGoogle Scholar
  17. 17.
    Haskell NA (1953) The dispersion of surface waves in multi-layered media. Bull Seismol Soc Am 43:17–34Google Scholar
  18. 18.
    Chen X (1993) A systematic and efficient method of computing normal modes for multilayered half space. Geophys J Int 115:391–409. Scholar
  19. 19.
    Acton CE, Priestley K, Mitra S, Gaur VK (2011) Crustal structure of Darjeeling-Sikkim Himalaya and southern Tibet. Geophys J Int 184:829–852. Scholar
  20. 20.
    Aki K, Richards PG (2002) Quantitative seismology, 2nd edn. University Science Books, Sausalito, CaliforniaGoogle Scholar
  21. 21.
    Zhu L, Rivera LA (2002) A note on the dynamic and static displacements from a point source in multilayered media. Geophys J Int 148:619–627. Scholar
  22. 22.
    Seismological Report on Sikkim Earthquake of 18th September 2011. Bulletin Series B, GSI (2014)Google Scholar
  23. 23.
    Roy A (2013) Waves in elastic solids. Levant Books, KolkataGoogle Scholar

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© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Department of MathematicsSiliguri CollegeSiliguriIndia

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