Lateral variations of the structure of the crust-mantle boundary from conversions of teleseismic P waves

Main Article Content

L. Qiyuan
R. Kind


Clear P-to-S converted phases are observed in teleseismic seismograms recorded at the Grafenberg array. The seismic events used are nuclear explosions from east Kasakh and deep-focus earthquakes from the region of Japan and central Asia. The identification of the converted phases has been improved by the rotation of the coordinate system. Theoretical seismograms have been computed to obtain the response of various velocity structures of the lithosphere under the receivers, using the reflectivity method of Kind (1985) for different source and receiver structures. The interpretation of the P-to-S conversions leads to a model of the crust-mantle transition zone with a first-order discontinuity and a normal velocity contrast in the north, an increased velocity contrast in the centre, and a reduced sharpness of the discontinuity in the south of the array. The sedimentary layers underneath the stations also cause strong converted phases, and they also influence strongly the waveform of the incoming P wave.

Google Scholar           ARK:



Article Details

How to Cite
Qiyuan, L., & Kind, R. (1986). Lateral variations of the structure of the crust-mantle boundary from conversions of teleseismic P waves. Journal of Geophysics, 60(1), 149-156. Retrieved from
Bookmark and Share


Aichele, H. (1976) Interpretation refraktionsseismischer Messungen im Gebiet des Frankisch-Schwabischen Jura. Dissertation, University of Stuttgart

Aki, K., Christofferson, A., Husebye, E.S. (1976) Three dimensional seismic structure of the lithosphere under Montana LASA. Bull. Seismol. Soc. Am. 66:501-524

Bath, M., Stefansson, R. (1966) S-P conversions at the base of the crust. Ann. Geofis. 19:119-130

Bock, G., Ha, J. (1984) Short-period S to P conversion in the mantle at a depth near 700 km. Geophys. J. R. Astron. Soc 77:593-615

Burdick, L.J., Langston, C.A. (1977) Modeling crustal structure through the use of converted phases in teleseismic body waves. Bull. Seismol. Soc. Am. 67:677-691

Faber, S., Muller, G. (1980) Sp phases from the transition zone between the upper and lower mantle. Bull. Seismol. Soc. Am. 70:487-508

Faber, S., Muller, G. (1984) Converted phases from the mantle transition zone observed at European stations. J. Geophys. 54:183-194

Faber, S., Plomerova, J., Babuska, V. (1986) Deep seated lateral velocity variations beneath the GRF array inferred from mislocation patterns and P residuals. J. Geophys. (In press)

Harjes, H.-P., Seidl, D. (1978) Digital recordings and analysis of broadband seismic data at the Grafenberg (GRF) array. J. Geophys. 44:511-523

Kind, R. (1985) The reflectivity method for different source and receiver structures and comparison with GRF data. J. Geophys. 58:146-152

Langston, C.A. (1979) Structure under Mount Rainier, Washington, inferred from teleseismic body waves. J. Geophys. Res. 84:4749-4762

Liu Qiyuan, Fan Hueiji (1986) Matrix-ray method for synthetic seismograms of body waves of earthquakes. Acta Geophysica Sinica (In press) (In Chinese with English abstract)

Liu Qiyuan, Shao Xuezhong (1985) A study of the dynamic characteristics of PS converted waves with synthetic seismograms. Acta Geophysica Sinica 28:291-302 (In Chinese with English abstract)

Plesinger, A., Hellweg, M., Seidl, D. (1986) Interactive high-resolution polarisation analysis of broadband seismograms. J. Geophys. 59:129-139

Polshkov, M.K., Bulin, K.N., Sherbakova, B.E. (1973) Crustal investigation of the U.S.S.R. by means of earthquake-generated converted waves. Tectonophysics 20:57-66

Shao Xuezhong, Zhang Jiru, Yang Xiaofeng, Zhang Xiaohu, Lei Shengli, Wang Qiming, Gao Weian (1978) An experimental study of the structure of the Earth's crust and upper mantle by converted waves. Acta Geophysica Sinica 21:89-100 (In Chinese with English abstract)

Shao Xuezhong, Zhang Jiaru, Liu Qiyuan, Zhang Siya (1986) The commong features of deep structures in some large earthquake areas of North China plain and their meaning to the earthquake site prediction. J. Phys. Earth (In press)

Vinnik, L.P. (1977) Detection of waves converted from P to SV in the mantle. Phys. Earth Planet. Inter. 15:39-45

Vinnik, L.P., Avetisjan, R.A., Mikhailova, N.G. (1983) Heterogeneities in the mantle transition zone from observations of P-to-SV converted waves. Phys. Earth Planet. Inter. 33:149-163