| More

APPLICATION OF 3-D VELOCITY MODELS AND RAY TRACING IN DOUBLE DIFFERENCE EARTHQUAKE LOCATION ALGORITHMS: APPLICATION TO THE MYGDONIA BASIN (NORTHERN GREECE)

Views: 258 Downloads: 236
O. C. Galanis, C. B. Papazachos, P. M. Hatzidimitriou, E. M. Scordilis
O. C. Galanis, C. B. Papazachos, P. M. Hatzidimitriou, E. M. Scordilis

Abstract


In the past years there has been a growing demand for precise earthquake locations for seismotectonic and seismic hazard studies. Recently this has become possible because of the development of sophisticated location algorithms, as well as hardware resources. This is expected to lead to a better insight of seismicity in the near future. A well-known technique, which has been recently used for relocating earthquake data sets is the double difference algorithm. In its original implementation it makes use of a one-dimensional ray tracing routine to calculate seismic wave travel times. We have modified the implementation of the algorithm by incorporating a three-dimensional velocity model and ray tracing in order to relocate a set of earthquakes in the area of the Mygdonia Basin (Northern Greece). This area is covered by a permanent regional network and occasionally by temporary local networks. The velocity structure is very well known, as the Mygdonia Basin has been used as an international test site for seismological studies since 1993, which makes it an appropriate location for evaluating earthquake location algorithms, with the quality of the results depending only on the quality of the data and the algorithm itself. The new earthquake locations reveal details of the area's seismotectonic structure, which are blurred, if not misleading, when resolved by standard (routine) location algorithms.


Full Text:

PDF

References


Aki, K. and Richards, P.G., 1980, Quantitative Seismology, vol. Il, W.H. Freeman and Company, 932pp.

Eaton, J. P., 1969, HYPOLAYR, a computer program for determining hypocenters of local earthquakes in an earth consisting of uniform flat layers over a half space, U.S. Geological Survey Open-File Report, 155 p.

Franklin, J.Ν., 1970. Well-posed stochastic extensions of ill-posed linear problems, J. Math. Anal. Appi., 31, 682-716.

Fréchet, J., 1985, Seismogenesis and seismic doublets, Ph.D. thesis. Scientific and Medical University of Grenoble, 206p. (in French).

Geiger, L, 1912, Probability method for the determination of earthquake epicenters from the arrival time only, (translated from Geiger's 1910 German article) Bulletin of St. Louis University, 8 (1), p. 56-71.

Got, J.-L, Fréchet, J., and Klein, F.W., 1994, Deep fault plane geometry inferred from multiplet relative relocation beneath the south flank of Kilauea, J. Geophys. R., 99, 15375-15386.

Lee, W. H. K., and Lahr, J. Α., 1972, HYP071: a computer program for determining hypocenter, magnitude and first motion pattern of local earthquakes, U.S. Geological Survey Open-File Report, 100 p.

Monteiller, V., 2003, High Resolution Tomography with the aid of seismic multiplets, Ph.D. thesis, Joseph Fourier University, Grenoble (in French).

Monteiller, V., Got, J.-L., Virieux, J. and Okubo, P.G., 2003, Double Difference Tomography of Kilauea Volcano, Hawaii, Geophysical Research Abstracts, 5, 05974.

Moser, T.J., 1991, Shortest path calculation of seismic rays, Geophysics, 56, 59-67.

Moser, T.J., Nolet, G., Snieder, R., 1992, Ray Bending Revisited, Bulletin of the Seismological Society of America, 82, 259-288.

Mountrakis, D.M., 1985, Geology of Greece, University Studio Press, Thessaloniki, 208 pp. (in Greek)

Mountrakis, D., Kilias, Α., Tranos, M., Thomaidou, E., Papazachos, C, Karakaisis, G., Skordilis, E., Hatzidimitriou, P., Papadimitriou, E., Vargemezis, G., Aidona, E., Karagianni, E., Vamvakaris, D. and Skarlatoudis, Α., 2003, Determination of the characteristics and the seismotectonic behavior of the main seismic-active faults of the Northern Greece Area with the use of neotectonic and seismic data, Earthquake Planning and Protection Organization (OASP). (in Greek)

Paige, C.C. and Saunders, M.A., 1982, LSQR - an algorithm for sparse linear equations and sparse least squares, ACM Transactions on Mathematical Software, 8, 43-71.

Papazachos, B., Mountrakis, D., Psilovikos, A. and Leventakis, G., 1979, Surface fault traces and fault plane solutions of May-June 1978 major shocks in the Thessaloniki area, Greece. Tectonophysics 53, 171-183.

Papazachos, C, 1998, Crustal P- and S-velocity structure of the Serbomacedonian Massif (Northern Greece) obtained by non-linear inversion of traveltimes, Geophys. J. Int., 134, 25-39.

Papazachos, C, Soupios, P., Sawaidis, A. and Roumelioti, Z., 2000. Identification of small-scale active faults near metropolitan areas: An example from the Asvestochori fault near Thessaloniki, Proc. XXVII ESC General Assembly, Lisbon, 10-15 September, 221-225.

Psilovikos, A and Sotiriadis, L, 1983, The neotectonic graben complex of the Sevomacedonian massif at the area of Promygdonia basin, in northern Greece, Clausthaler Geologische Abhandlungen, 44, 21-53.

Snieder, R. and Sambridge, M., 1992, Ray perturbation theory for traveltimes and ray paths in threedimensional heterogeneous media, Geophysical Journal International, 109, 294-322.

Waldhauser, F., 2001, hypoDD - A program to compute double-difference hypocenter locations, U.S. Geol. Survey Open File Report 01-113, 25pp.

Waldhauser, F. and Ellsworth, W.L., 2000, A double-difference earthquake location algorithm: Method and application to the northern Hayward fault, Bull. Seism. Soc. Am., 90, 1353-1368.

Wessel, P. & Smith, W. 1995. New version of the Generic Mapping Tools. EOS Trans. Amer. Geophys. U., 76:329.


Refbacks

  • There are currently no refbacks.


Copyright (c) 2018 O. C. Galanis, C. B. Papazachos, P. M. Hatzidimitriou, E. M. Scordilis

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.