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  • 1 MCT/Observatório Nacional R: Gal. José‚ Cristino 77, S?o Cristóv?o, 20921-400 Rio de Janeiro, Brazil
  • 2 MCT/Observatório Nacional R: Gal. José‚ Cristino 77, S?o Cristóv?o, 20921-400 Rio de Janeiro, Brazil
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Seismic coda Qattenuation (Qc) in the frequency range from 6 to 20 Hz of two distinct Scoda windows (early and later portions) are compared to analyse the effects of both coda windows on crustal seismic attenuation estimates around Samambaia fault (João CâmaraNortheastern Brazil). Qcvalues associated with the later portion are systematically higher than those related to the early portion. These values follow a frequency (f) function given by Qc(f) = Q0f, where Q0= 11739 and= 1.000.06. In general, Q0estimate is less sensitive to site effects and stabler than that obtained from the early portion of S coda waves, while its corresponding frequency dependence is similar to that obtained from the early portion of S coda waves. It suggests thatparameter does not depend on coda window's location along the seismic signal. A comparative analysis of both Q0andvalues with those found recently shows that there is no difference in using early or later portion of S coda waves in the stations located on Pre-Cambrian basement in the João Câmara area. This comparison also shows that the major variations in Q0values were observed at seismic stations installed on sedimentary terrain. Differences in the seismic attenuation, in both sides of the Samambaia fault, were also observed in this study, and it is in agreement with the hypothesis that Samambaia fault is a kind of boundary between two seismic attenuation zones.

  • Takeya M K 1992: PhD Thesis, University of Edinburgh, Great Britain

  • Souza J L de 1996c: Geofísica Internacional, 35, 301-314.

    () 35 Geofísica Internacional : 301 -314.

  • Souza J L de, Mitchell B J 1998: Pure Appl. Geophys., 153, 587-612.

    () 153 Pure Appl. Geophys. : 587 -612.

  • Souza J L de 1996a: An. Acad. bras. Ci., 68, 41-63.

    () 68 An. Acad. bras. Ci. : 41 -63.

  • Souza J L de 1996b: Geofísica Internacional, 35, 285-300.

    () 35 Geofísica Internacional : 285 -300.

  • Souza J L de 1991: Pure and Appl. Geophys., 136, 604-624.

    () 136 Pure and Appl. Geophys. : 604 -624.

  • Souza J L de 1995: Geophys. J. Int., 122, 691-702.

    () 122 Geophys. J. Int. : 691 -702.

  • Sato H 1977: J. Phys. Earth, 25, 27-41.

    () 25 J. Phys. Earth : 27 -41.

  • Shedlock K M, Giardini D, Grünthal G, Zhang P 2000: Seism. Res. Lett., 71, 679-686.

    () 71 Seism. Res. Lett. : 679 -686.

  • Sherbune R W 1975: PhD Thesis, Pennsylvania State University, USA

  • Dias A P, Souza J L de 2004: Journal of Seismology, 8, 235-246.

    () 8 Journal of Seismology : 235 -246.

  • Assumpção M 1992: J. Geophys. Res., 97, 11889-11903.

    () 97 J. Geophys. Res. : 11889 -11903.

  • Aki K, Chouet B 1975: J. Geophys. Res., 80, 3322-3342.

    () 80 J. Geophys. Res. : 3322 -3342.

  • Carvalho L A 2003: MSc Dissertation, MCT - Observatório Nacional, Rio de Janeiro, Brazil (in Portuguese)

  • DNPM 1983: Projeto mapas metalogenéticos e de previsão de recursos minerais. Mapatectono-estrutural : Natal, folha SB. 25-V-C (1 : 250000)

  • Duarte O de O 1984: Manual de Subrotinas, Quarta Edção, PETROBRÁS, Rio de Janeiro, Brasil

  • Ferreira J M 1997: PhD Thesis, Instituto Astronmico e Geofísico, Universidade de São Paulo, São Paulo, Brazil (in Portuguese)

  • Barazangi M, Isacks B 1976: Geology, 4, 686-692.

    () 4 Geology : 686 -692.

  • Carvalho L A, Souza J L de 2003: CR-ROM of the 8th International Congress of the Brazilian Geophysical Society and 5th Latin American Geophysical Conference (in Portuguese)

  • Chinn D, Isacks B, Barazangi M 1976: EOS Trans. Am. Geophys. Union, 57, 334.

    () 57 EOS Trans. Am. Geophys. Union : 334.

  • Chinn D, Isacks B, Barazangi M 1980: Geophys. J. R. astr. Soc., 60, 209-244.

    () 60 Geophys. J. R. astr. Soc. : 209 -244.

  • Barazangi M, Pennington W, Isacks B 1975: J. Geophys. Res., 80, 1079-1092.

    () 80 J. Geophys. Res. : 1079 -1092.

  • Stauder W 1975: J. Geophys. Res., 80, 1053-1064.

    () 80 J. Geophys. Res. : 1053 -1064.

  • Stauder W 1973: J. Geophys. Res., 78, 5033-5061.

    () 78 J. Geophys. Res. : 5033 -5061.

  • Ferreira J M, Takeya M K, Costa J M, Moreira J A M, Assumpção M, Veloso J A, Pearce R G 1987: Geophys. Res. Lett., 14, 1402-1405.

    () 14 Geophys. Res. Lett. : 1402 -1405.

  • Ferreira J M, Oliveira R T, Takeya M K, Assumpção M 1998: Geophys. J. Int., 134, 341-355.

    () 134 Geophys. J. Int. : 341 -355.

  • Haberland C, Rietbrock A 2001: J. Geophys. Res., 106, 11151-11167.

    () 106 J. Geophys. Res. : 11151 -11167.

  • Hwang H-J, Mitchell B J 1987: Geophys. J. R. astr. Soc., 90, 575-613.

    () 90 Geophys. J. R. astr. Soc. : 575 -613.

  • Osagie E O 1986: Geophys. J. R. astr. Soc., 86, 1-17.

    () 86 Geophys. J. R. astr. Soc. : 1 -17.

  • Padilha A L, da Costa I V J M, Trivedi N B 1992: Acta Geod. Geoph. Mont. Hung., 27, 111-119.

    () 27 Acta Geod. Geoph. Mont. Hung. : 111 -119.

  • Raoof M M, Nuttli O 1985: Pure Appl. Geophys., 122, 619-644.

    () 122 Pure Appl. Geophys. : 619 -644.

  • Renbarger K S 1984: MSc Dissertation, The University of Texas at El Paso, USA

  • Takeya M, Ferreira J M, Pearce R G, Assumpção M, Costa J M, Sophia C M 1989: Tectonophysics, 167, 117-131.

    () 167 Tectonophysics : 117 -131.

  • Wessel P, Smith W H F 1998: EOS Trans. Amer. Geophys. U., 79, 579.

    () 79 EOS Trans. Amer. Geophys. U. : 579.

  • Whitman D, Isacks B L, Chatelain J-L, Chiu J-M, Perez A 1992: J. Geophys. Res., 97, 19929-19947.

    () 97 J. Geophys. Res. : 19929 -19947.

  • Sacks I S 1977: Tectonophysics, 37, 131-139.

    () 37 Tectonophysics : 131 -139.

  • Aki K 1969: J. Geophys. Res., 74, 615-631.

    () 74 J. Geophys. Res. : 615 -631.

  • James D E 1971: Bull. Geol. Soc. America, 82, 3325-3346.

    () 82 Bull. Geol. Soc. America : 3325 -3346.

  • Jordan T E, Isacks B L, Allmendinger R W, Brewer J A, Ramos V A, Ando C J 1983: Bull. Geol. Soc. America, 94, 341-361.

    () 94 Bull. Geol. Soc. America : 341 -361.

  • Molnar P, Oliver J 1969: J. Geophys. Res., 74, 2648-2682.

    () 74 J. Geophys. Res. : 2648 -2682.