Skip to main content
Log in

Seismicity and source parameters of moderate earthquakes in Sikkim Himalaya

  • Original Paper
  • Published:
Natural Hazards Aims and scope Submit manuscript

Abstract

In this study, we accurately relocate 360 earthquakes in the Sikkim Himalaya through the application of the double-difference algorithm to 4 years of data accrued from a eleven-station broadband seismic network. The analysis brings out two major clusters of seismicity—one located in between the main central thrust (MCT) and the main boundary thrust (MBT) and the other in the northwest region of Sikkim that is site to the devastating Mw6.9 earthquake of September 18, 2011. Keeping in view the limitations imposed by the Nyquist frequency of our data (10 Hz), we select 9 moderate size earthquakes (5.3 ≥ Ml ≥ 4) for the estimation of source parameters. Analysis of shear wave spectra of these earthquakes yields seismic moments in the range of 7.95 × 1021 dyne-cm to 6.31 × 1023 dyne-cm and corner frequencies in the range of 1.8–6.25 Hz. Smaller seismic moments obtained in Sikkim when compared with the rest of the Himalaya vindicates the lower seismicity levels in the region. Interestingly, it is observed that most of the events having larger seismic moment occur between MBT and MCT lending credence to our observation that this is the most active portion of Sikkim Himalaya. The estimates of stress drop and source radius range from 48 to 389 bar and 0.225 to 0.781 km, respectively. Stress drops do not seem to correlate with the scalar seismic moments affirming the view that stress drop is independent over a wide moment range. While the continental collision scenario can be invoked as a reason to explain a predominance of low stress drops in the Himalayan region, those with relatively higher stress drops in Sikkim Himalaya could be attributed to their affinity with strike-slip source mechanisms. Least square regression of the scalar seismic moment (M 0) and local magnitude (Ml) results in a relation LogM 0 = (1.56 ± 0.05)Ml + (8.55 ± 0.12) while that between moment magnitude (M w ) and local magnitude as M w  = (0.92 ± 0.04)Ml + (0.14 ± 0.06). These relations could serve as useful inputs for the assessment of earthquake hazard in this seismically active region of Himalaya.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

  • Abercrombie RE (1995) Earthquake source scaling relationship from −1 to 5 ML using seismograms recorded at 2.5-km depth. J Geophys Res 100:24015–24036

    Article  Google Scholar 

  • Aki K (1967) Scaling law of seismic spectrum. Bull Seismol Soc Am 72:1217–1231

    Google Scholar 

  • Aki K, Richards PG (2002) Quantitative seismology, 2nd edn. University Science Books, Sausalito, CA

    Google Scholar 

  • Allen I, Trevor Gibson G, Brown A, Cull JP (2004) Depth variation of seismic source scaling relations: implications for earthquake hazard in southeastern Australia. Tectonophysics 390:5–24

    Article  Google Scholar 

  • Allmann BP, Shearer PM (2009) Global variation of stress drop for moderate to large earthquakes. J Geophys Res 114:B-131. doi:10.1029/2008JB005821

    Google Scholar 

  • Andrews DJ (1986) Objective determination of source parameters and similarity of earthquakes of different size. In: Das et al. (Eds) Earthquake source mechanics. Ewing Series, 6, AGU, Washington DC www1986, pp 259–267

  • Archuleta RJ, Cranswick E, Mueller C, Spudich P (1982) Source parameters of the 1980 Mammoth Lakes. California, earthquake sequence. J Geophys Res 87:4595–4607

    Article  Google Scholar 

  • Baltay A, Ide S, Prieto G, Beroza G (2011) Variability in earthquake stress drop and apparent stress. Geophys Res Lett 38:L06303. doi:10.1029/2011GL046698

    Article  Google Scholar 

  • Bansal BK (1998) Determination of source parameters for small earthquake in the Koyna region, 11th symposium on earthquake engineering. Roorkee 1:57–66

    Google Scholar 

  • Boatwright J (1980) A spectral theory for seismic sources: simple estimates of source dimension, dynamic stress drop and radiator energy. Bull Seism Soc Am 70:1–27

    Google Scholar 

  • Boore DM, Campbell WC, Atkinson GM (2010) Determination of stress parameters for eight well-recorded earthquakes in Eastern North America. Bull Seism Soc Am 100:1632–1645. doi:10.1785/0120090328

    Article  Google Scholar 

  • Brune JN (1970) Tectonic stress and seismic shear waves from earthquakes. J Geophys Res 75:4997–5009

    Article  Google Scholar 

  • Brune JN (1971) Correction. J Geophys Res 76:5002

    Article  Google Scholar 

  • Chevrot S, Cansi Y (1996) Source spectra and site-response estimates using the coda of Lg waves in western Europe. Geophys Res Lett 23:1605–1608

    Article  Google Scholar 

  • Chouliaras G, Stavrakakis GN (1997) Seismic source parameters from a new dial-up seismological network in Greece. Pure Appl Geophys 150:91–111

    Article  Google Scholar 

  • Cotte N, Pedersen H, Campillo M, Mars J, Ni J, Kind R, Sandvol E, Zhao W (1999) Determination of the crustal structure in Southern Tibet by dispersion and amplitude analysis of Rayleigh waves. Geophys J Int 138:809–819

    Google Scholar 

  • Deichmann N (2006) Local magnitude. A moment revisited. Bull Seism Soc Am 96:1267–1277. doi:10.1785/0120050115

    Article  Google Scholar 

  • Drouet S, Souriau A, Cotton F (2005) Attenuation, seismic moment, and site effects for weak-motion events: application to the Pyrenees. Bull Seismol Soc Am 95(5):1731–1748

    Article  Google Scholar 

  • Drouet S, Chevrot S, Cotton F, Souriau A (2008) Simultaneous Inversion of Source Spectra, Attenuation Parameters and Site Responses: Application to the data of the French Accelerometric Network. Bull Seism Soc Am 98:198–219. doi:10.1785/0120060215

    Article  Google Scholar 

  • Drukpa D, Velasco AA, Doser DI (2006) Seismicity in the Kingdom of Bhutan (1937–2003): evidence for crustal transcurrent deformation. J Geophys Res B Solid Earth Planets 111:B06301

    Google Scholar 

  • Eshelby J (1957) The determination of the elastic field of an ellipsoidal inclusion and related problems. Proc R Soc Lond A 241:376–396

    Article  Google Scholar 

  • Fletcher JB (1980) A comparison between high-dynamic range digital recordings of Oroville, California aftershocks and their source parameters. Bull Seism Soc Am 70:735–755

    Google Scholar 

  • Fletcher JB, Boatwright J, Harr L, Hanks T, McGarr A (1984) Source parameters for aftershocks of the Oroville, California earthquake. Bull Seism Soc Am 74:1101–1123

    Google Scholar 

  • GSI (2000) Seismotectonic Atlas of India and its environs

  • Gupta DI, Rambabu V (1993) Source parameters of some significant earthquakes near Koyna Dam, India. Pageop 140:403–413

    Article  Google Scholar 

  • Gupta HK, Singh DD (1980) Spectral analysis of body waves for earthquakes in Nepal Himalaya and vicinity: their focal parameters and tectonic implications. Tectonophysics 62:53–66

    Article  Google Scholar 

  • Hanks TC, Boore DM (1984) Moment-Magnitude relations in theory and practice. J Geophys Res 89:6229–6235

    Article  Google Scholar 

  • Hanks TC, Kanamori H (1979) A moment magnitude scale. J Geophys Res 84:2348–2350

    Article  Google Scholar 

  • Havskov J, Ottemöller L (2003) SEISAN: the earthquake analysis software, version 8.0, Institute of Solid Earth Physics, University of Bergen, Bergen, Norway

  • Hazarika P, Kumar MR, Srijayanthi G, Raju PS, Rao NP, Srinagesh D (2010) Transverse Tectonics in Sikkim Himalaya: evidences from seismicity and focal mechanism data. Bull Seism Soc Am 100:1816–1822. doi:10.1785/0120090339

    Article  Google Scholar 

  • Herrmann RB, Kijko A (1983) Modelling some empirical vertical component Lg relations. Bull Seismol Soc Am 75:157–171

    Google Scholar 

  • Hiramatsu Y, Yamanaka H, Tadokoro K, Nishigami K, Ohmi S (2002) Scaling law between corner frequency and seismic moment of microearthquakes: is the breakdown of cube law a nature of earthquake? Geophys Res Lett 29:1211. doi:10.1029/2001GL013894

    Article  Google Scholar 

  • Hough SE (1996) Observational constraints on earthquake source scaling: understanding the limits in resolution. Tectonophysics 261:83–95

    Article  Google Scholar 

  • Johnson LR, McEvilly TV (1974) Near field observations and source parameters of Central California earthquakes. Bull Seismol Soc Am 64:1855–1886

    Google Scholar 

  • Kato N (2009) A possible explanation for difference in stress drop between intraplate and interplate earthquakes. Geophys Res Lett 36:L23311. doi:10.1029/2009GL040985

    Article  Google Scholar 

  • Kayal JR, Baruah S, Baruah S, Gautam JL, Arefiev SS, Tatevossian R (2011) The September 2011 Sikkim deeper centroid Mw 6.9 earthquake: role of transverse faults in eastern Himalaya, DCS-DST News

  • Kim WY, Wahlstrom R, Uski M (1989) Regional spectral scaling relations of source parameters for earthquakes in the Baltic Shield. Tectonophysics 166:151–161

    Article  Google Scholar 

  • Kumar D, Ram VS, Khattri KN (2006) A study of source parameters, site amplification functions and average effective shear wave quality factor qseff from analysis of accelerograms of the 1999 Chamoli earthquake, Himalaya. Pure Appl Geophys 163:1369–1398

    Google Scholar 

  • Kumar D, Sarkar I, Sriram V, Khattri KN (2005) Estimation of the source parameters of the Himalaya earthquake of October 19, 1991, average effective shear wave attenuation parameter and local site effects from accelerograms. Tectonophysics 407:1–24

    Article  Google Scholar 

  • Mandal PK, Rastogi BK, Sarma CSP (1998) Source parameters of Koyna earthquakes, India. Bull Seism Soc Am 88:833–842

    Google Scholar 

  • Mayeda K, Malagnini L, Walter WR (2007) A new spectral ratio method using narrow band coda envelopes: evidence for non-self-similarity in the Hector Mine sequence. Geophys Res Lett 34:L11303. doi:10.1029/2007GL030041

  • O’Neill ME (1984) Source dimension and stress drops of small earthquakes near Parkfield, California. Bull Seism Soc Am 71:27–40

    Google Scholar 

  • Ottemoller L, Havskov J (2003) Moment magnitude determination for local and regional earthquakes based on source spectra. Bull Seism Soc Am 93:203–214

    Article  Google Scholar 

  • Pearson C (1982) Parameters and a magnitude moment relationship for small earthquakes observed during hydraulic fracturing experiments in crystalline rocks. Geophys Res Lett 9:404–407

    Article  Google Scholar 

  • Prieto GA, Shearer PM, Vernon FL, Kilb D (2004) Earthquake source scaling and self-similarity estimation from stacking P and S spectra. J Geophys Res 109:B08310. doi:10.1029/2004JB003084

    Article  Google Scholar 

  • Raj A, Nath SK, Bansal BK, Thingbaijam KKS, Kumar A, Thiruvengadam N, Yadav A, Arrawatia ML (2009) Rapid estimation of source parameters using finite fault modeling-Case studies from the Sikkim and Garhwal Himalayas. Seism Res Lett 80(1):89–96

    Article  Google Scholar 

  • Rajendran K, Rajendran CP, Thulasiraman N, Andrews R, Sherpa N (2011) The 18 September, North Sikkim earthquake: a preliminary report. Curr Sci 101:1475–1479

    Google Scholar 

  • Ram VS, Kumar D, Khattri KN (2005) The 1986 Dharamsala earthquake of Himachal Himalaya – estimates of source parameters, average intrinsic attenuation and site amplification functions. J Seismol 9:473–485

    Google Scholar 

  • Sharma ML, Wason HR (1994) Occurrence of low stress drop earthquakes in the Garhwal Himalaya region. Phys Earth Planet Inter 85:265–722

    Article  Google Scholar 

  • Shi J, Kim WY, Richards PG (1998) The corner frequencies and stress drops of intraplate earthquakes in the Northeastern United States. Bull Seism Soc Am 88:531–542

    Google Scholar 

  • Singh DD, Rastogi BK, Gupta HK (1978) Spectral analysis of body waves for earthquakes and their source parameters in the Himalaya and nearby regions. Phys Earth Planet Inter 18:143–152

    Article  Google Scholar 

  • Singh SK, Apsel RJ, Fried J, Brune JN (1982) Spectral attenuation of SH-waves along the Imperial fault. Bull Seism Soc Am 72:2003–2016

    Google Scholar 

  • Thatcher W, Hanks TC (1973) Source parameters of southern California earthquakes. J Geophys Res 78:8547–8576

    Article  Google Scholar 

  • Tucker BE, Brune JN (1977) Source mechanism and mb–Ms analysis of aftershocks of the San Fernando earthquake. Geophys J 74:6617–6672

    Google Scholar 

  • Waldhauser F (2001) HypoDD—a program to compute double-difference hypocenter locations. US Geol Survey Open File Report 113:1–25

  • Wyss M, Brune JN (1968) Seismic moment, stress and source dimensions for earthquakes in the California-Nevada region. J Geophys Res 73:4681–4694

    Article  Google Scholar 

  • Wyss M, Brune JN (1971) Regional variation of source properties in southern California estimated from the ratio of short to long period amplitudes. Bull Seismol Soc Am 61:1153–1168

    Google Scholar 

  • Yen YT, Ma KF (2011) Source-scaling relationship for M 4.6-8.9 earthquakes, specifically for earthquakes in the collision zone of Taiwan. Bull Seismol Soc Am 101:464–481. doi:10.1785/0120100046

    Article  Google Scholar 

Download references

Acknowledgments

The SIKKIM experiment is supported by the Seismology Division of the Department of Science and Technology (presently under Ministry of Earth Sciences), India, under the project DST/23(337)/SU/2002. We sincerely thank P. Solomon Raju, Vijaya Raghavan and Satish Saha for providing excellent support for conducting the experiment. We are grateful to two anonymous reviewers, whose comments have significantly improved the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Pinki Hazarika.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hazarika, P., Ravi Kumar, M. Seismicity and source parameters of moderate earthquakes in Sikkim Himalaya. Nat Hazards 62, 937–952 (2012). https://doi.org/10.1007/s11069-012-0122-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11069-012-0122-8

Keywords

Navigation