- Open Access
Fault low velocity zones deduced by trapped waves and their relation to earthquake rupture processes
Earth, Planets and Space volume 54, pages1045–1048(2002)
Detailed structures of fault low velocity zones (LVZ) have been studied by analyzing fault-zone trapped waves at various active faults. These studies demonstrate that widths of the fault LVZ are ranging from an order of 10 m to a few hundred meters. In order to evaluate the effect of fault LVZ on the earthquake rupture process, a model of the LVZ related to the plastic deformation around an edge of propagating earthquake rupture is proposed. In this study, earthquake rupture processes are regarded as Mode III crack propagation. The LVZ is identical to the fault damaged zone which is related to plastic deformation in the vicinity of the crack tip. The Mode III crack analysis gives a simple relationship between the width of the low velocity zone, the breakdown stress drop at the crack tip, and characteristic slip distance d0 in friction laws. The parameters applicable to the Nojima fault producing the 1995 Hyogo-ken Nanbu earthquake show that the breakdown stress drop is 10 times larger than the static stress drop and d0 is about 10 cm. These values are consistent with the value obtained by the other study for the Nojima fault so the present model is applicable for considering earthquake rupture within the damaged zone.
Aki, K., Characterization of barriers on an earthquake fault, J. Geophys. Res., 84, 6140–6148, 1979.
Andrew, J., Rupture propagation with finite stress in antiplane strain, J. Geophys. Res., 81, 3575–3582, 1976a.
Andrew, J., Rupture velocity of plane strain shear cracks, J. Geophys. Res., 81, 5679–5687, 1976b.
Barenblatt, G. I., The formation of equilibrium cracks during brittle fracture: General idea and hypothesis, J. Appl. Math. Mech., 23, 622–636, 1959.
Fujita, K. and O. Ikuta, Resistivity structure of the central part of the Yamasaki fault studied by the multiple electrodes resistivity method, Earth Planets Space, 52, 567–571, 2000.
Guatteri, M., P. Spudich, and G. C. Beroza, Inferring rate and state friction parameters from a rupture model of the 1995 Hyogo-ken Nanbu (Kobe) Japan earthquake, J. Geophys. Res., 106, 26511–26521, 2001.
Harris, R. and S. Day, Effect of a low-velocity zone on a dynamic rupture, Bull. Seism. Soc. Am., 87, 1267–1280, 1997.
Ida, Y., Cohesive force across the tip of a longitudinal-shear crack and Griffith’s specific surface energy, J. Geophys. Res., 77, 3796–3805, 1972.
Ide, S. and M. Takeo, Determination of constitutive relation of fault slip based on seismic wave analysis, J. Geophys. Res., 102, 27379–27391, 1997.
Ito, H. and Y. Kuwahara, Trapped waves along the Nojima fault from the aftershock of Kobe earthquake, 1995, Proceedings of VIIIth International Symposium on the observation of the Continental Crust Trough Drilling, 399–402, 1996.
Ito, H., Y. Kuwahara, T. Miyazai, O. Nishizawa, T. Kiguchi, K. Fujimoto, Y. Ohtani, H. Tanaka, T. Higuchi, S. Agar, A. Brie, and H. Yamamoto, Structure and physical properties of the Nojima fault by the Active fault drilling, Geophys. Explor., 49, 522–535, 1996.
Ito, H., K. Nishigami, and Y. Kuwahara, Fault guided waves at the Mozumi-Sukenobu fault, central Japan, Geophys. Res. Lett., 2002 (in preparation).
Kuwahara, Y., K. Imanishi, and H. Ito, Seismic trapped wave observation in the fault zone of the Western Tottori earthquake of 2000, Program abstract of Japan Earth and Planetary Sci. Joint meeting, 2001.
Li, Y.-G., P. C. Leary, K. Aki, and P. E. Malin, Seismic trapped modes in the Oroville and San Andreas fault zones, Science, 249, 763–766, 1990.
Li, Y.-G., K. Aki, D. Adams, and A. Hasemi, Seismic guided waves trapped in the fault zone of the Landers, California, earthquake of 1992, J. Geophys. Res., 99, 11705–11722, 1994.
Li, Y.-G., K. Aki, and F. L. Vernon, San Jacinto fault zone guided waves: A discrimination for recently active fault strands near Anza, California, J. Geophys. Res., 102, 11689–11701, 1997.
Mooney, W. D. and A. Ginzburg, Seismic measurements of the internal properties of fault zones, Pure Appl. Geophys., 124, 141–157, 1986.
Ohnaka, M., Critical size of the nucleation zone of earthquake rupture inferred from immediate foreshock activity, J. Phys. Earth, 41, 45–46, 1993.
Rice, J. R., The mechanics of earthquake rupture, in Physics of the Earth’s Interior, edited by A. Dziewonski and E. Boshi, pp. 555–649, Italian Physical Society, Amsterdam, North Holland, 1980.
Schmidt, R. A. and H. P. Rossmanith, Basics of rock fracture mechanics, in Rock Fracture Mechanics, edited by H. P. Rossmanith, pp. 1–29, Springer, Verlag, 1983.
Shibazaki, B. and M. Matsu’ura, Transition process from nucleation to highspeed rupture propagation: scaling from stick-slip experiments to natural earthquakes, Geophys. J. Int., 132, 14–30, 1998.
Stuart, W. D., R. J. Archuleta, and A. G. Lindh, Forecast model for moderate-earthquake near Parkfield, California, J. Geophys. Res., 90, 592–604, 1985.
Takeuchi, A., H. Ongirad, and T. Akimitsu, Recurrence interval of big earthquakes along the Atotsugawa fault system, central Japan—Results of Seismo-geological survey, Geophys. Res. Lett., 2002 (submitted).
Tanaka, H., K. Fujimoto, T. Ohtani, and H. Ito, Structural and chemical characterization of shear zones in the freshly activated Nojima fault, Awaji island, southwest Japan, J. Geophys. Res., 106, 8789–8810, 2001.
Tse, S. T. and J. R. Rice, Crustal earthquake instability in relation to the depth variation of frictional slip properties, J. Geophys. Res., 91, 9425–9472, 1986.
Unsworth, M., G. Egbert, and J. Booker, High-resolution electromagnetic imaging of the San Andreas fault in Central California, J. Geophys. Res., 104, 1131–1150, 1999.
About this article
Cite this article
Kuwahara, Y., Ito, H. Fault low velocity zones deduced by trapped waves and their relation to earthquake rupture processes. Earth Planet Sp 54, 1045–1048 (2002). https://doi.org/10.1186/BF03353299
- Earthquake Rupture
- Trap Wave
- Plastic Deformation Zone
- Static Stress Drop
- Nojima Fault