S Velocity Probing of Ontong-Java Plateau by Analyzing Seismograms of B041196C Earthquake

Bagus J. Sentosa

Abstract


This research investigates the S wave velocity structure under Ontong-Java Plateau in Equator Western Pacific using seismogram analysis of B041196F earthquake at various observatory stations. The analyzed wave phases are the S wave, Love and Rayleigh surface wave phases and core reflected ScS and ScS2 wave phases. Seismogram comparison shows different discrepancies that depend on the azimuth direction from hypocenter. South East area of OJP has positive anomaly that differs from the other previously seismological research in the same area. Eastwards area of OJP has negative anomaly like the other result of seismological research. On other azimuth direction indicates that positive anomaly occurred not only in the upper mantle but also at mantle layers till CMB.

Keywords


Seismogram comparison; S wave velocity anomaly; vertical anisotropy in the mantle layers till CMB

Full Text:

PDF

References


Gomer, B.M. and Okal, E.A., 2003, Multiple-ScS Probing of the Ontong-Java Plateau, Phys. of the Earth and Plan. Int., 138, 317– 331.

Dziewonski, A.M. and Anderson, D.L., 1981, Preliminary Reference Earth Model, Phys. of the Earth and Plan. Int., 25, 297 – 356.

Richardson, W.P., Okal, E.A., and Van der Lee, S., 2000. Rayleigh- Wave Tomography of the Ontong-Java Plateau, Phys. Earth Plan. Int., 118, 29 – 51.

Evans, J.R. and Sacks, I.S., 1979, Deep Structure of the Iceland Plateau. J. Geophys. Res., 84, 6859 – 6866.

Okal, E.A. and Anderson, D.L., 1975, A study of Lateral Inhomogeneities in the Upper Mantle by Multiple ScS Travel- Time Residuals. Geophys. Res. Lett., 2, 313 – 316.

Sipkin, S.A. and Jordan, T.H., 1976, Lateral Heterogeneity of the Upper Mantle Determined from the Travel Times of Multiple ScS. J. Geophys. Res., 81 , 6307 – 6320.

Dalkolmo, J., 1993, Synthetische Seismogramme Fuer Eine Sphaerisch Symmetrische, Nichtrotierend Erde Durch Direkte Berechnung der Greenschen Funktion, Diplomarbeit, Inst. fuer Geophys., Uni. Stuttgart.

Friederich, W. and Dalkolmo, J., 1995, Complete Synthetic Seismograms for a Spherically Symmetric Earth by a Numerical Computation of the Green's Function in the Frequency Domain, Geophys. J. Int., 122, 537 – 550.

Santosa, B.J., 1999, Moeglichkeiten and Grenzen der Modellierung Vollstaendiger Langperiodischer Seismogramme, Doktorarbeit, Berichte Nr. 12, Inst. fuer Geophysik, Uni. Stuttgart.

Dreger, D.S., 2002, Time-Domain Moment Tensor INVerse Code (TDMT_INVC), The Berkeley Seismological Laboratory (BSL), report number 8511.

Talandier, J. and Okal, E.A., 1998, On the Mechanism of Conversion of Seismic Waves to and from T Waves in the Vicinity of Island Shores. Bull. Seismol. Soc. Am., 88, 621 – 632.

Yu Guo, J., Lerner-Lam, A. L., Dziewonski, A.M. and Ekström, G., 2005, Deep Structure and Seismic Anisotropy Beneath the East Pacific Rise, Earth and Planetary Science Letters, 232, 259 -272.




DOI: http://dx.doi.org/10.12962/j20882033.v20i3.107

Refbacks

  • There are currently no refbacks.


Creative Commons License

IPTEK Journal of Science and Technology by Lembaga Penelitian dan Pengabdian kepada Masyarakat, ITS is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Based on a work at http://iptek.its.ac.id/index.php/jts.