Spatial variations in the frequency-magnitude distribution of earthquakes in the southwestern Okinawa Trough
Earth, Planets and Space volume 59, pages 221–225 (2007)
The relations between the frequency of occurrence and the magnitude of earthquakes are established in the southern Okinawa Trough for 2823 relocated earthquakes recorded during a passive ocean bottom seismometer experiment. Three high b-values areas are identified: (1) for an area offshore of the Ilan Plain, south of the andesitic Kueishantao Island from a depth of 50 km to the surface, thereby confirming the subduction component of the island andesites; (2) for a body lying along the 123.3°E meridian at depths ranging from 0 to 50 km that may reflect the high temperature inflow rising up from a slab tear; (3) for a third cylindrical body about 15 km in diameter beneath the Cross Backarc Volcanic Trail, at depths ranging from 0 to 15 km. This anomaly might be related to the presence of a magma chamber at the base of the crust already evidenced by tomographic and geochemical results. The high b-values are generally linked to magmatic and geothermal activities, although most of the seismicity is linked to normal faulting processes in the southern Okinawa Trough.
Aki, K., Maximum likelihood estimate of b in the formula logN=a-bM and its confidence limits, Bull. Earthq. Res. Inst., Tokyo Univ., 43, 237–239, 1965.
Bender, B., Maximum likelihood estimation of b-values for magnitude grouped data, Bull. Seismol. Soc. Am., 73, 831–851, 1983.
Chang, T.-Y., J.-C. Sibuet, C.-S. Lee, and J.-Y. Lin, Tremors in the Southwestern Okinawa Trough., Tectonophysics, 2006 (submitted).
Chen, C. H., T. Lee, Y. N. Hsieh, C.-H. Chen, and W. Y. Hsu, Magmatism at the onset of back arc basin spreading in Okinawa Trough, J. Volcanol. Geotherm. Res., 69, 313–322, 1995.
Engdahl, E. R., R. D. Van der Hilst, and R. P. Buland, Global teleseismic earthquake relocation with improved travel times and procedures for depth determination, Bull. Seismol. Soc. Am., 88, 722–743, 1998.
Font, Y., S. Lallemand, and J. Angelier, Etude de la transition entre l’orogène actif de Taiwan et la subduction des Ryukyu—Apport de la sismicité, Bull. Soc. Géol. Fr., 170, 271–283, 1999.
Fournier, M., O. Fabbri, J. Angelier, and J.-P. Cadet, Regional seismicity and on-land deformation in the Ryukyu Arc: Implications for the kinematics of opening of the Okinawa Trough, J. Geophys. Res., 106, 13,751–13,768, 2001.
Frohlich, C. and S. Davis, Teleseismic b values: Or, much ado about 1.0, J. Geophys. Res., 98, 631–644, 1993.
Glasby, G. P. and K. Notsu, Submarine hydrothermal mineralization in the Okinawa Trough, SW Japan: an overview, Ore. Geol. Rev., 23 (3–4), 299–339, 2003.
Gutenberg, R. and C. F. Richter, Frequency of earthquakes in California, Bull. Seismol. Soc. Am., 34, 185–188, 1944.
Hsu, S.-K., J.-C. Sibuet, and C.-T. Shyu, Magnetic inversion of the East China Sea and Okinawa Trough: Tectonic implications, Tectonophysics, 333, 111–122, 2001.
Ishimoto, M. and K. Iida, Observations of earthquakes registered with the microseismograph constructed recently, Bull. Earthq. Res. Inst., 17, 443–478, 1939.
Kao, H. and P.-R. Jian, Seismogenic patterns in the Taiwan region: Insights from source parameter inversion of BATS data, Tectonophysics, 333, 179–198, 2001.
Kissling, E., W. L. Ellsworth, D. Eberhart-Phillips, and U. Kradolfer. Initial reference models in local earthquake tomography, J. Geophys. Res., 99, 19635–19646, 1994.
Kubo, A. and E. Fukuyama, Stress field along the Okinawa Trough and the Ryukyu Arc inferred from moment tensors of shallow earthquakes, Earth Planet. Sci. Lett., 210, 305–316, 2003.
Lee, Y. L., The study of active submarine volcanoes and hydrothermal vents in the southernmost part of Okinawa Trough, Master thesis, National Taiwan Ocean University, Taiwan, 45 pp, 2005 (in Chinese).
Lin, J.-Y., S.-K. Hsu, and J.-C. Sibuet, Melting features along the Ryukyu slab tear, beneath the southwestern Okinawa Trough, Geophys. Res. Lett., 31, L19607, doi:10.1029/2004GL020862, 2004a.
Lin, J.-Y., S.-K. Hsu, and J.-C. Sibuet, Melting features along the western Ryukyu slab edge (northeast Taiwan): Tomographic evidence, J. Geo-phys. Res., 109, B12402, doi:10.1029/2004JB003260, 2004b.
Lin, J.-Y., J.-C. Sibuet, C. S. Lee, S.-K. Hsu, and F. Klingelhoefer, Origin of the southern Okinawa Trough volcanism from detailed seismic tomography, J. Geophys. Res., 2006a (accepted).
Lin, J.-Y., J.-C. Sibuet, C. S. Lee, S.-K. Hsu, F. Klingelhoefer, Y. Auffret, P. Pelleau, and J. Crozon. Microseisismicity and faulting in the southwestern Okinawa Trough, Tectonophysics, 2006b (revised).
Murru, M., C. Montuori, M. Wyss, and E. Privitera, The location of magma chambers at Mt. Etna, Italy, mapped by b-values, Geophys. Res. Lett., 26, 2553–2556, 1999.
Power, J. A., M. Wyss, and J. L. Latchman, Spatial variations in frequency-magnitude distribution of earthquakes at Soufrière Hills volcano, Montserrat, West Indies, Geophys. Res. Lett., 25, 3653–3656, 1998.
Reyners, M., D. Eberhart-Phillips, G. Stuart, and Y. Nishimura, Imaging subduction from the trench to 300 km depth beneath the central North Island, New Zealand, with Vp and Vp/Vs, Geophys. J. Int., 165(2), 565–583, 2006.
Scholz, C. H., The frequency-magnitude relation of microfracturing in rock and its relation to earthquakes, Bull. Seismol. Soc. Am., 58, 399–415, 1968.
Schorlemmer, D., S. Wiemer, and M. Wyss, Wariations in earthquake-size distribution across different stress regimes, Nature, 437, doi:10.1038/nature04094, 2005.
Shaw, B. E., Frictional weakening and slip complexity in earthquake faults, J. Geophys. Res., 100, 18,239–18,252, 1995.
Shinjo, R., S. Hokakubo, S. Haraguchi, T. Matsumoto, and J. Woodhead, Geochemical characteristics of volcanic rocks from the southern Okinawa Trough and its implications for tectonomagmatic evolution, EOS Trans. AGU, 84(46), Fall Meet. Suppl., Abstract V31E-0973, 2003a.
Shinjo, R., S. Hokakubo, S. Haraguchi, and T. Matsumoto, Regional variation in geochemistry of volcanic rocks from the southern Okinawa Trough, Earth Mon., 43, 21–26, 2003b (in Japanese).
Sibuet, J.-C., B. Deffontaines, S.-K. Hsu, N. Thareau, J.-P. Le Formal, and C.-S. Liu, The southwestern Okinawa Trough back-arc basin: Tectonics and volcanism., J. Geophys. Res., 103, 30,245–30,267, 1998.
Sibuet, J.-C. and S.-K. Hsu, How was Taiwan created?, Tectonophysics, 379, 159–181, 2004.
Thurber, C. H. and D. Eberhart-Phillips, Local earthquake tomography with flexible gridding, Comput. Geosci., 25, 809–818, 1999.
Urbancic, T. I., C. I. Trifu, J. M. Long, and R. P. Toung, Space-time correlations of b-values with stress release, PAGEOPH, 139, 449–462, 1992.
Wang, C., M.-L. Yang, C.-P. Chou, Y.-C. Chang, and C.-S. Lee, Westward extension of the Okinawa Trough and its western end in the northern Taiwan area: Bathymetric and seismological evidence, Terr. Atm. Oc. Sci., 372, 167–177, 2000.
Warren, N. W. and G. V. Latham, An experimental study of thermally induced microfracturing and its relation to volcanic seismicity, J. Geo-phys. Res., 75, 4455–4464, 1970.
Watanabe, T., Effects of water and melt on seismic velocities and their application to characterization of seismic reflectors, Geophys. Res. Lett., 20, 2933–2936, 1993.
Wessel, P. and W. M. F. Smith, Free software helps map and display data, EOS Trans. Am. Geophys. Union, 72, 441–446, 1991.
Wiemer, S., A software package to analyze seismicity: ZMAP, Seismol. Res. Lett., 72, 373–382, 2001.
Wiemer, S. and M. Wyss, Seismic quiescence before the 1993 M=7.5 Landers and M=6.5 Big Bear (California) earthquakes, Bull. Seismol. Soc. Am., 84, 900–916, 1994.
Wiemer, S. and M. Wyss, Mapping the frequency-magnitude distribution in asperities: An improved technique to calculate recurrence times?, J. Geophys. Res., 102, 15,115–15,128, 1997.
Wiemer, S. and M. Wyss, Mapping spatial variability of the frequency-magnitude distribution of earthquakes, Adv. Geophys., 45, 259–302, 2002.
Wiemer, S., S. R. McNutt, and M. Wyss, Temporal and three-dimensional spatial analysis of the frequency-magnitude distribution near Long Valley caldera, California, Geophys. J. Int., 134, 409–421, 1998.
Wyss, M., Towards a physical understanding of the earthquake frequency distribution, Geophys. J. R. Astr. Soc., 31, 341–359, 1973.
About this article
Cite this article
Lin, JY., Sibuet, JC., Lee, CS. et al. Spatial variations in the frequency-magnitude distribution of earthquakes in the southwestern Okinawa Trough. Earth Planet Sp 59, 221–225 (2007). https://doi.org/10.1186/BF03353098