Crustal Thickness of Funafuti Using Receiver Function Analysis

V. Srivardhan

Department of Applied Geophysics, Indian School of Mines, Dhanbad, India.

DOI: 10.4236/ijg.2013.410129                

Abstract

In this study, the characterization of the depth of the Mohorovicic discontinuity under the crust of Funafuti island was determined by analyzing the 3 component seismograms from 54 different earthquake events recorded by the station between 2008 and 2012. These seismograms were from teleseismic earthquakes whose epicenter lay at distances greater than 3000 km from the station. The seismograms were iteratively deconvolved in the time domain to remove the unwanted noise and then stacked to obtain better receiver functions. For analysis of the receiver functions, it was assumed that the range in which the Vp/Vs ratio would lie for the given region would be between 1.60 - 1.85 and the depth of the discontinuity was assumed to lie between 5 - 20 km. Analysis of the receiver functions showed that the Mohorovicic discontinuity was at a depth of 11 km and the Vp/Vs ratio was 1.75 for the region.

Keywords

Receiver Function Analysis; Funafuti; Mohorovicic Discontinuity; Deconvolution of Three Component Seismogram; Iterative Time Domain Deconvolution

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	R. N. Jansson, “Receiver Function Modeling,” MS Thesis, University of Copenhagen, Copenhagen, 2008.
[2]	H. Tiegan and D. A. Fiona, “Point Estimates of Crustal Thickness Using Receiver Function Stacking,” McGill Science Undergraduate Research Journal, Vol. 7, No. 1, 2012, pp. 21-27.
[3]	Y. L. Chen, F. L. Niu, R. F. Liu, Z. B. Huang, H. Tkalcic, L. Sun and W. Chan, “Crustal Structure Beneath China from Receiver Function Analysis,” Journal of Geophysical Research, Vol. 115, 2010, Article ID: B03307.
[4]	W. Lowrie, “Fundamentals of Geophysics,” Cambridge University Press, Cambridge, 2007.
[5]	S. Stein and M. Wysession, “An Introduction to Seismology, Earthquakes, and Earth Structure,” Blackwell Publishing Ltd, Malden, 2003.
[6]	M. P. Shearer, “Introduction to Seismology,” Cambridge University Press, Cambridge, 2009.
[7]	C. A. Langston, “Structure under Mount Rainer, Washington, Inferred from Teleseismic Body Waves,” Journal of Geophysical Research, Vol. 84, No. B9, 1979, pp. 4749-4762. http://dx.doi.org/10.1029/JB084iB09p04749
[8]	J. P. Ligorria and C. J. Ammon, “Iterative Deconvolution and Receiver Function Estimation,” Bulletin of the Seismological. Society of America, Vol. 89, No. 5, 1999, pp. 1395-1400.
[9]	A. K. Pesce, “Comparison of Receiver Function Deconvolution Techniques,” MS Thesis, Massachusetts Institute of Technology, 2010.
[10]	C. Escalante, J. Y. Gu and M. Sacchi, “Simultaneous Iterative Time-Domain Sparse Deconvolution to Teleseismic Receiver Functions,” Geophysical Journal International, Vol. 171, No. 1, 2007, pp. 316-325. http://dx.doi.org/10.1111/j.1365-246X.2007.03511.x
[11]	M. Kikuchi and H. Kanamori, “Inversion of Complex Body Waves,” Bulletin of the Seismological Society of America, Vol. 72, No. 2, 1982, pp. 491-506.
[12]	J. F. Cassidy, “Numerical Experiments in Broadband Receiver Function Analysis,” Bulletin of the Seismological Society of America, Vol. 82, No. 3, 1992, pp. 1453-1474.
[13]	G. T. Bonney, “The Atoll of Funafuti: Borings into a Coral Reef and the Results. Being the Report of the Coral Reef Committee,” The Royal Society of London, London, 1904.
[14]	T. Cooksey, “Rock Specimens from Funafuti,” Australian Museum, Sydney, 2012.
[15]	A. Holmes and D. L. Holmes, “Principles of Physical Geology,” 3rd Edition, ELBS and Nelson, Hamshire, 1978.
[16]	C. Xue and F. Malologa, “Coastal Sedimentation and Coastal Management of Fongafale, Funafuti Atoll, Tuvalu,” SOPAC Technical Report 221, 1995.
[17]	L. Zhu and H. Kanamori, “Moho Depth Variation in Southern California from Teleseismic Receiver Functions,” Journal of Geophysical Research, Vol. 105, No. B2, 2000, pp. 2969-2980. http://dx.doi.org/10.1029/1999JB900322