pn10-15.fm

Transcription

1 k Jigu-Mulli-wa-Mulli-Tamsa Vol. 13, No. 3, 2010, p. 277~285 w ûw k * w œw A Review of the Study of the South Korea Tae Woong Chung* Department of Energy & Mineral Resources Engineering, Sejong University w Lgqƒ s w. ûw Lgq d ú û. g ³ y, œm w Lgq û ùkùš. ûw, Lgq, Q Lg, Abstract: For regional earthquakes in the Korean Peninsula, the seismic Lg waves have the largest amplitude. Our researches in South Korea found that more reasonable low was obtained as the inter-station distances increase. The other methods such as coda normalization method and multiple lapse time window method also produced that the low is related to the values of seismically inactive region. Keywords: South Korea, Lg waves, Q Lg, seismically inactive region œœ w vwƒ w ƒ, w d z ƒ ƒw š. p w ³ 5.2(» t) ù y w ³ 5.0 z ƒ j ³». w j w ³ 7.0 (zi e ) ƒ¾ «w, w w vw öe y» k š, ü w ü» m y w z š. ƒ¾ ù j v w j, ƒ vw ƒ ; ; k *Corresponding author chungtw@sejong.ac.kr Address: Department of Energy & Mineral Resources Engineering, Sejong University, Seoul , Korea ƒ d q s y d w Q ùkü, Q ü dw» w v. Ÿ w ƒ š, w Pq Sq Q w w û š ( ; k, 2001; Á, 2000;, 2001; 2004; Chung and Sato, 2001a; 2001b; Kim et al., 2004; Chung et al., 2006). wr w x ƒ q ƒ q Lgqƒ w x ùkù (e.g. Furumura and Kennett, 2001). p zi e, ƒ j q, Lgqƒ s Lgq Q ü w. w w w x k w Lgq w œs (e.g. Cong et al., 1996) mw Lgq Q š ƒ, w x w ƒ (e.g. Hong et al., 2008; Hong and Lee, 2009). w ƒ, ûw w y w ƒ ( k, 2002, 2008, 2009;, 2009;, 2004, 2009; Chung and Lee, 2002, 2003; Chung et al., 2005, 2007, 2010; Hong, 277

2 278 k 2010),» w ûw Lgq Q w w» w. Lg q ûw ƒ Lg q Press Ewing (1952)» p w 2 t q w Lgq Rgq š w,»ƒ m t q w š t t q ù Lgq w Ú Loveq q w. q q ƒ ƒ w ùkùš, w ƒ 100 km m w. w w 2km w ƒ x. w» r, Lgq 3.5 km/s ƒ j qx, 2.9 km/s ¼ z (Fig. 1). Lgq t y Sqƒ w w š. Sato and Fehler (1998) Lg (Q Lg )ƒ w y w w d mw w. p 1 Hz y w x, y y w w (Aki, 1980a; Jin and Aki, 1988). w ƒ w d» q Lgq w ù( ; Furumura and Kennett, 2001), w ûw d š z l ƒ ûw š, w Lg qx» w ƒ. ûw ƒ ûw sww w q w» j ù ûw 1905» d M L 5 3 w., ƒ q w yw w ù 200 Ms ³ 5 50z w (Chung and Brantley, 1989). ûw ƒ w Lee (1979)ƒ ûw ƒ ̃ 35 km š tw z, ½ ½ (1983) 15 km ¾ ƒ w ƒ ù, Pq ƒ 5.98 km/s, 6.38 km/s p 7.95 km/s w. ƒ š w w w ù, z Fig. 1. The typical Lg waves observed in KRA station (35.33 o N, o E) with epricentral distances R( ). The velocity windows 3.5 ~ 2.9 km/s was denoted as solid lines with arrows. w (Chung, 1995; k, 1999;, 1999) w ƒ, w ƒ, w» (KMA) ù (KIGAM) w w t š. ûw û wš x» w e» ƒ y w xkƒ Ÿ w r. û û x» w n Ÿ w s w (Lee, 1974). d w Aki (1080b) Coda rp Sq q rp w w, q q Codaq ù q œm w w w w Coda³ y š w. d wù ƒ w d, Pq(Yoshimoto et al., 1993) Lgq(Frankel et al., 1990) y. Chung and Lee (2003) d w w 4 d s³ f 0.51 (Fig. 2), w û w Q s ew ( Sato, 2000; k, 2001;, 2001; Chung and Sato, 2001a, 2001b). w û Q s y ƒ û w x. Q s ƒ y w (Fig. 2), y ks g (Domnguez et al., 1997), e s (Benz et al., 1997; Paul et al., 1996; Domnguez and Rebollar, 1997), (Sereno et al., 1988), q e (Shi et

3 ûw 279 d w Fig. 2. The of our results with error bars, and other studies. Circles with C and N represent the value of California and New York State, respectively (Frankel et al., 1990). Frequency-dependent values are classified into three regions of seismicity; the thick solid lines from 1 to 5 denote active regions, the thin solid lines from 6 to 10 denote moderate regions, and the broken lines from 11 to 15 denote inactive regions: 1, Granada basin, southern Spain (De Miguel et al., 1992); 2, subduction zone in Mexico (Domínguez et al., 1997); 3, Sierra Nevada, California (Paul et al., 1996); 4, southern California (Benz et al., 1997); 5, northern Baja California (Domínguez and Rebollar, 1997); 6, Basin and Range province (Benz et al., 1997); 7, central France (Campillo et al., 1985); 8, Great Basin (Chávez and Priestley, 1986); 9, Tibetian Plateau (McNamara et al., 1996); 10, eastern Kazakhstan (Sereno, 1990); 11, Norway (Sereno et al., 1988); 12, central Appalachia (Shi et al., 1996); 13, southeastern Canada (Atkinson and Mereu, 1992); 14, Canadian shield (Hasegawa, 1985); 15, Adirondack mountains in the United States (Shi et al., 1996). This figure is modified version of Chung et al. (2005). al., 1996) (Shi et al., 1996) (Frankel, 1990), eù (Chun et al., 1987) (Atkinson and Mereu, 1992; Hasegawa, 1985) û, y (Benz et al., 1997), v (Campillo et al., 1985), s (Chvez and Priestley, 1986), p p š (McNamara et al., 1996), e k (Sereno, 1990). w, Frankel et al.(1990) w y w ûe s j 3 Hz šw (Fig. 2 C, N). Aki (1980b) w ƒ ƒü ³» w w. ûw error barƒ š q, eù û w., Coda³ y w Frankel et al. (1990) š z w š w mƒ v w y. Chun et al. (1987) 2 2 d w d z z w d w, Reversed Two Station Method (RTSM) š w. RTSM»¾ œ Lgq d ( ; Xie et al., 2006), d d. RTSM d (SP)ƒ yw w, SP w ƒ ù., r û e w ù (De Miguel et al., 1992) y w (Fig. 2). w w ƒ 250 km w, RTSM SP 60 km w w. w û 180 km, SP < 53 km RTSM Q P ( f ) = f.48 (½ ³, 1999), 380 km, SP < 100 km RTSM Coda ³ y 10 w š (Chung and Lee, 2002; k, 2002). w SP v ƒ Q w ƒ y y w. Ou and Herrmann (1990) 200 km w (1) t q 0.5 j Atkinson and Mereu (1992) 130 km w j y w. eù û (Shi et al., 1996) 1300 km ¼ d w, eù 867 km, SP 210 km l Chun et al. (1987) w û Q œwš. wr, Shih et al. (1994) Lg y»w d sz ƒ w š ƒ w RTSM 2 2 d yw source pair/receiver pair (SPRP) š w. Chung et al. (2005) SPRP w w RTSM 50 km ¼ SP y w w y y ƒ û œw (Fig. 2). ù SPRP w RTSM w, p w(fan and Lay, 2003) w j. w j SPRP w (Shih et al., 1994) ùkù, Shih et al. Ÿ w w w v. Shih et al. (1994) w

4 280 k w ù, w j ƒ w, ƒ w wƒ w ƒ w ƒ w ³ z. w w 3» w y y w y y m w É w ƒ swš (Hirata et al., 1989; Chung et al., 1990; Chung and Kanazawa, 1991; Chung, 1992; Kim et al., 1994). wš 1.5 Hz Coda (Chung and Lee, 2003) w, w š (Fig. 2). w Ÿ RTSM w d (SP) y SPRP w ƒ Lg w (Fan and Lay, 2003), k (2008) Chung and Lee (2002) k (2002) SP w» w w d s ûw w RTSM w. d w 112 km 260 km SP y w ù, RTSM SPRP ù Coda³ y w y w w w y w š ƒ. Chun (Personal Communication) w w Lgq w» w d w w, d y ƒ j w ƒ š w. w RTSM SP ¼ w mw v». k (2009) IRIS (Incorporated Research Institutions for Seismology) ù sww d w 1000 km SP d w RTSM d w, y w. wr Xie et al. (2006) Lg Ÿ w, w w yw m vw Lg w w, 1 Hz y w. w, y. ù, w IRIS d w, ƒ Lgq». w yw m vw Lg ¾, w w Fig. 3. Tomographic values of Q Lg * The low values are denoted as dark color. (modified from Chung et al., 2007). x w œ w x w m vw Lg w š. Chung et al. (2007) IRIS d ü ww RTSM w w m v w Lg y w., w 193 w Q o ww ƒ ù w w Fig. 3 w. Fig. 3 p w Q o û Q o. w ƒ 30 km Ì w ƒ¾ 3000 m w 8.5 km Ì (Hirata et al., 1992). Q o ƒ y k w, û Q o y w š w. wr, Hong (2010) Lgq s rp (Sereno et al., 1988; Xie and Patton, 1999) rp w sw p g q ( fc) Xie (2002), Q w w m vw Lg wþ, w Q o w. Q š (Q i ) (Q s )ƒ ww

5 ûw 281 Lgq š q ƒ w š w z w. š Q i ƒ q k ù xk yw, Q s q, y ùkü. x w š w š w ( ; Stocker and Gordon, 1975; Kampfmann and Berckhemer, 1985), w y k w» w š w ƒ ww š w ( ; Chung et al., 2009). y, ƒ g Q d ( ;, 2004). g Q d Sqƒ Source ƒ, w d k ( ; Aki, 1969, Aki and Chouet, 1975). w š w ý ƒ, š Q i Sq q g q s jš, Q s Sq q j g q s j w š w. w e Hoshiba (1991)ƒ w š Zeng et al. (1991) Sato (1993)ƒ w ü. d g q s mw š w w Multiple Lapse Time Window method (MLTW ) Hoshiba et al. (1991) Fehler et al. (1992) w ( ; Sato and Fehler, 1998). Mayeda et al. (1992) MLTW w y w y e s w š w š, Canas et al. (1998) w e ú y ƒ Q i Q s. wr œx w d ƒ ƒ, y w y Q i Q s š (Hoshiba, 1993). w š š, š ƒp wƒ w. (2009) w Lgq š q w š e Fehler et al. (1992) w (MLTW) ƒ q w ww, k (2009a) w w g Q šw. w q Yoshimoto (2000) le w q w w w Q šw ( k, 2009b; Fig. 4. Comparison of intrinsic Q i for uniform model of South Korea (2010; 2009) and worldwide regions. Grey lines represent the values of volcanic regions Mt. Fuji (Chung et al., 2009), Hawaii, Central California, Long Valley (Mayeda et al., 1992), Kagoshima, Chubu, Shikoku in Japan (Hoshiba, 1993), Canary Island (Canas et al., 1998). Dashed lines are following regions South Apennines (Bianco et al., 2002), Furiuri, Italia (Bianco et al., 2005), Southern Spain (Akinci et al., 1995), Almeria, Southeastern Spain (Pujades et al., 1997). This figure is modified from Chung et al. (2010). Fig. 5. Comparison of scattering Q s for uniform model of South Korea (2010; 2009) and worldwide regions. The regions are the same for Fig. 4 (modified from Chung et al., 2010).

6 282 k Chung et al., 2010). w w ƒ (Lee et al., 2010; Chung and Yoshimoto, 2010). Chung et al. (2010) (2009) w Fig. 4, 5 wš w. z z (Chung et al., 2009), w (Mayeda et al., 1992), eú (Canas et al., 1998), eš (Hoshiba, 1993) y Q i» œ. t e s Long Valley (Mayeda et al., 1992), gã(hoshiba, 1993), k û r (Bianco et al., 2002) Firiuli (Bianco et al., 2005) y r û (Akinci et al., 1995) Almeria (Pujades et al., 1997) w w œ. w Q i û ùkùš. ûw Lgq Q, RTSM (Reversed two station method) SPRP (Source Pair Receiver Pair) d ú û. g ³ y, œm w Lgq û ùkùš w ü w. š x ½, ½, 1983, q w ûw ƒ, w Ÿ wz, 16, ½ ³,, ½, 1999, Pq, w wz, 35, »y, k, 1999, w û w ƒ, w wz, 2, 1-8. k, 2001, w û ƒ Pq Sq, w wz, 22, k, 2002, Reversed Two Station Method w, w wz, 5, k, 2008, w Lgq w w RTSM w, k, 11, k, 2009a, w g Q, k, 12, k, 2009b,, k, 12, k,,», 1999, ûw ƒ, w wz, 20, k, w, 2000, w w û š q P Sq, w wz, 3, k, w,»y, 2001, w û 9 d y Coda³ y w w û Q P Q S, w wz, 22, k,, z, x, Ÿx, x,,,, ½, 2004, w ƒ (Q-Structure), w» š, KINS/HR-641, pp k,, 2009, (MLTW) w, k, 12, k, k, x, 2009, w Lgq,»» š, CATER , pp k, Lees, J. M., 2008, R qj w m v, k, 11, k, Lees, J. M.,, 2008, R w, k, 11, Aki, K., 1969, Analysis of the seismic coda of local earthquakes as scattered waves, Journal of Geophysical Research, 74, Aki, K., 1980a, Scattering and attenuation of shear waves in the lithosphere, Journal of Geophysical Research, 85, Aki, K., 1980b, Attenuation of shear waves in the lithosphere for frequencies from 0.05 to 25 Hz, Physics of the Earth and Planetary Interiors, 21, Aki, K. and Chouet, B., 1975, Origin of coda waves; source, attenuation and scattering effects, Journal of Geophysical Research, 80, Atkinson, G. M., and Mereu, R., 1992, The shape of ground motion attenuation curves in southeastern Canada, Bulletin of the Seismological Society of America, 82, Benz, H. M., Frankel, A., and Boore, D. M., 1997, Regional Lg attenuation for the continental United States, Bulletin of the Seismological Society of America, 87, Bianco, F., Del Pezzo, E., Akinci, A., Di Luccio, F., Malagnini, L., and Anonymous, Depth dependent intrinsic and scattering attenuation in the lithospheric structure of the Friuli region, Italy, Eos, Transactions, American Geophysical Union, 83, 990. Bianco, F., Del Pezzo, E., Malagnini, L., Di Luccio, F., and Akinci, A., 2005, Separation of depth-dependent intrinsic and scattering seismic attenuation in the northeastern sector of the Italian Peninsula, Geophysical Journal International, 161, Campillo, M., Plantet, J. L., and Bouchon, M., 1985, Frequencydependent attenuation in the crust beneath central France from Lg waves: data analysis and numerical modeling, Bulletin of the Seismological Society of America, 75,

7 ûw 283 Canas, J. A., Ugalde, A., Pujades, L. G., Carracedo, J. C., Soler, V., and Blanco, M. J., 1998, Intrinsic and scattering seismic wave attenuation in the Canary Islands, Journal of Geophysical Research, 103, Chun, K.-Y., West, G. F., Kokoski, R. J., and Samson, C., 1987, A novel technique for measuring Lg attenuation Results from eastern Canada between 1 to 10 Hz, Bulletin of the Seismological Society of America, 77, Chung, T. W., 1992, A quantitative study of seismic anisotropy in the Yamato Basin, the southeastern Japan Sea, from refraction data collected by an ocean bottom seismographic array, Geophysical Journal International, 109, Chung, T. W., 1995, A quantitative study on the crustal structure of the Korean Peninsula based on the earthquakes from 1991 to 1994, Journal of Korean Earth Sciences Society, 16, Chung, T. W., and Sato, H., 2001a, Attenuation of high-frequency P- and S-waves in the crust of the southeastern Korea, Bulletin of the Seismological Society of America, 91, Chung, T. W., and Sato, H., 2001b, A preliminary study on the attenuation of high-frequency P and S waves in the crust of the Yangsan fault area, southeastern South Korea, Science Report of Tohoku University, Seriese 5, 36, Chung, T. W., Lees, J. M., Yoshimoto, K., Fujita, E., Ukawa, M., 2009, Intrinsic and scattering attenuation of the Mt. Fuji region, Japan, Geophysical Journal International, 177, Chung, T. W., and Lee, K., 2002, Attenuation of high-frequency Lg waves around the Yangsan Fault area, the southeast Korea, Journal of Korean Geophysical Soc. 5, 1-8. Chung, T. W., and Lee, K., 2003, A study of high-frequency in the crust of south Korea, Bulletin of the Seismological Society of America, 93, Chung, T. W., Noh, M. H., Kim, J. K., Park, Y. K., Yoo, H. J., and Lees, J. M., 2007, A Study of the Regional Variation of Low-Frequency around the Korean Peninsula, Bulletin of the Seismological Society of America, 97, Chung, T. W., Noh, M. H., and Matsumoto, S., 2006, The attenuation structure of the South Korea: A review, Journal of the Korean Geophysical Society, 9, Chung, T. W., Hirata, N., and Sato, R., 1990, Two dimensional P and S-wave velocity structure of the Yamato Basin, the southeastern Japan Sea, from refraction data collected by an ocean bottom seismographic array, Journal of Physics of the Earth, 38, Chung, T. W. and Kanazawa, T., 1991, Sn observation in the Yamato Basin, the southeastern Japan Sea, from refraction data collected by an ocean bottom seismographic array, Journal of Physics of the Earth, 39, Chung, T. W., Park, Y. K., Kang, I. B., and Lee, K., 2005, Crustal in South Korea using the source pair/receiver pair method, Bulletin of the Seismological Society of America, 95, Chung, T. W., and Yoshimoto, K., 2010, A study of the separation of intrinsic and scattering seismic attenuation in southeastern South Korea, based on the velocity structure, Bulletin of the Seismological Society of America, in submitted. Chung, T. W., Yoshimoto, K., and Yun, S., 2010, The Separation of intrinsic and scattering seismic attenuation in South Korea, Bulletin of the Seismological Society of America, in press. Chung, W. Y., and Brantley, B. J., 1989, The 1984 southern Yellow Sea earthquake of eastern China: source properties and seismotectonic implications for a stable continental area, Bulletin of the Seismological Society of America, 79, Cong, L., Xie, J., and Mitchell, B. J., 1996, Excitation and propagation of Lg from earthquakes in central Asia with implications for explosion/earthquake discrimination, Journal of Geophysical Research, 101, 27,779-27,789. De Miguel, F., Ibanez, J. M., Alguacil, G., Canas, J. A., Vidal, F., Morales, J., Pea, J. A., Posadas, A. M., and Luzn, F., 1992, 1-18 Hz Lg attenuation in the Granada Basin (southern Spain), Geophysical Journal International, 111, Domnguez, T., and Rebollar, C. J., 1997, Regional variations of seismic attenuation from coda and Lg waves in northern Baja California, Journal of Geophysical Research, 102, Domnguez, T., Rebollar, C. J., and Castro, R. R., 1997, Regional variations of seismic attenuation of Lg waves in southern Mexico, Journal of Geophysical Research, 102, Fan, G. W., and Lay, T., 2003, Strong Lg wave attenuation in the northern and eastern Tibetian Plateau measured by a twostation/two-event stacking method, Geophysical Research Letter, 30, 1530, doi: /2002gl Fehler, M., Hoshiba, M., Sato, H., and Obara, K., 1992, Separation of scattering and intrinsic attenuation for the Kanto-Tokai region, Japan, using measurements of S-wave energy versus hypocentral distance, Geophysical Journal International, 108, Frankel, A., McGarr, A., Bicknell, J., Mori, J., Seeber, L., and Cranswick, E., 1990, Attenuation of high-frequency shear waves in the crust: measurements from New York State, South Africa and southern California, Journal of Geophysical Research, 95, Furumura, T., and Kennett, B. L. N., 2001, Variation in regional phase propagation in the area around Japan, Bulletin of the Seismological Society of America, 91, Hasegawa, H. S., 1985, Attenuation of Lg waves in the Canadian shield, Bulletin of the Seismological Society of America, 75, Hirata, N., Tokuyama, H., and Chung, T. W., 1989, An anomalously thick layering of the crust of the Yamato Basin, southeastern Japan Sea: the final stage of back-arc spreading, Tectonophysics, 165, Hoshiba, M., Simulation of multiple-scattered coda wave excitation based on the energy conservation law, Physics of the Earth Planetary Interiors, 67, Hoshiba, M Separation of scattering attenuation and intrinsic absorption in Japan using the multiple lapse time

8 284 k window analysis of full seismogram envelope, Journal of Geophysical Research, 98, 15,809-15,824. Hoshiba, M., Sato, H., and Fehler, M., 1991, Numerical basis of the separation of scattering and intrinsic absorption from full seismogram envelope: a Monte- Carlo simulation of multiple isotropic scattering, Papers in Meteorology and Geophysics, 42, Hong, T.-K., Baag, C.-E. Choi, H., and Sheen, D.-H. Sheen, 2008, Regional seismic observations of the 9 October 2006 underground nuclear explosion in North Korea and the influence of crustal structure on regional phases, Journal of Geophysical Research, 113, B03305, doi /2007JB Hong, T.-K. and Rhie, J., 2009, Regional Source Scaling of the 9 October 2006 Underground Nuclear Explosion in North Korea, Bulletin of the Seismological Society of America, 99, Hong, T.-K., 2010, Lg Attenuation in a region with both continental and oceanic environments, Bulletin of the Seismological Society of America, 100, Jin, A., and Aki, K., 1988, Spatial and temporal correlation between coda Q and seismicity in China, Bulletin of the Seismological Society of America, 78, Kampfmann, W., and Berckhemer, H., High temperature experiments on the elastic and anelastic behavior of magmatic rocks, Physics of the Earth and Planetary Interiors, 40, Kim, H. J., Park, C. H., Hong, J. K., Jou, H. T., Chung, T. W., Zhigulef, V., and Anosov, G. I., 1994, A seismic experiment in the Ulleung basin, East sea of Korea, Geophysical Research Letter, 21, Kim, K. D., Chung T. W., and Kyung, J. B., 2004, Attenuation of high- frequency P and S waves in the crust of Choongchung provinces, central south Korea, Bulletin of the Seismological Society of America, 94, Kvamme, L. B., and Havskov, J., 1989, Q in Southern Norway. Bulletin of the Seismological Society of America, 79, Lee, S. M., 1974, The tectonic setting of Korea, with relation to plate tectonics, Journal of Geological Society of Korea, 10, Lee, K., 1979, On crustal structure of the Korean Peninsula, Journal of Geological Society of Korea, 15, Lee, W. S., Yun, S., and Do, J.-Y., 2010, Scattering and intrinsic attenuation of short-period S waves in the Gyeongsang Basin, South Korea, revealed from S-wave seismogram envelopes based on the radiative transfer theory, Bulletin of the Seismological Society of America, 100, Mayeda, K., Koyanagi, S., Hoshiba, M. Aki, K., and Zeng, Y., 1992, A comparative study of scattering, intrinsic, and coda - 1 Q for Hawaii, Long Valley, and central California between 1.5 and 15.0 Hz, Journal of Geophysical Research, 97, McNamara, D. E., Owens, T. J., and Walter, W. R., 1996, Propagation characteristics of Lg across the Tibetian Plateau, Bulletin of the Seismological Society of America, 86, Ou, G. B., and Herrmann, R. B., 1990, Statistical model for ground motion produced by earthquakes at local and regional distances, Bulletin of the Seismological Society of America, 80, Paul, A., Jongmans, D., Campillo, M. Malin, P., and Baumont, D., 1996, Amplitude of regional seismic phases in relation to crustal structure of the Sierra Nevada, California, Journal of Geophysical Research, 101, Pujades, L., Ugalde, G. A., Canas, J. A., Navarro, J. M., Badal, F. J., and Corchete, V., 1997, Intrinsic and scattering attenuation from observed seismic codas in the Almeria Basin (southeastern Iberian peninsula), Geophysical Journal International, 129, Press, F., and Ewing, M., 1952, Two slow surface waves across North America, Bulletin of the Seismological Society of America, 43, Sato, H., 1993, Energy transportation in one- and two-dimensional scattering media; analytic solutions of the multiple isotropic scattering model, Geophysical Journal International, 112, Sato, H. and Fehler, M. C., 1998, Seismic wave propagation and scattering in the heterogeneous earth, Springer-Verlag New York, Inc. 308 pp. Sereno, T. J., 1990, Frequency-dependent attenuation in eastern Kazakhstan and implications for seismic detection thresholds in the Soviet Union, Bulletin of the Seismological Society of America, 80, Sereno, T. J., Bratt, S. R., and Bache, T. C., 1988, Simultaneous inversion of regional wave spectra for attenuation and seismic moment in Scandinavia, Journal of Geophysical Research, 93, Shi, J., Kim, W. Y., and Richard, P. G., 1996, Variability of crustal attenuation in the northeastern United States from Lg waves, Journal of Geophysical Research, 101, Shih, X. R., Chun, K. -Y., and Zhu, T., 1994, Attenuation of 1-6 s Lg waves in Eurasia, Journal of Geophysical Research, 99, Stocker, R. L. and Gordon, R. B., 1975, Velocity and internal friction in partial melts, Journal of Geophysical Research, 80, Taylor, S. R., Bonner, B. P., and Zandt, G., 1986, Attenuation and scattering of broadband P and S waves across North America, Journal of Geophysical Research, 91, Xie, J., 2002, Source scaling of Pn and Lg spectra and their ratios from explosions in central Asia: Implications for the identification of small seismic events at regional distances, Journal of Geophysical Research, 107(B7), 2128, doi: / 2001JB Xie, J., and Patton, H. J., 1999, Regional phase excitation and propagation in the Lop or region of central Asia and implications for P/Lg discriminants, Journal of Geophysical Research, 104, Xie, J., Wu, A., Liu, R., Schaff, D., Liu, Y., and Liang, J., 2006, Tomographic regionalization of crustal Lg Q in eastern Eurasia, Geophysical Research Letter, 33, L03315, doi /

9 ûw GL Yoshimoto, K., 2000, Monte Carlo simulation of seismogram envelopes in scattering media. Journal of Geophysical Research, 105, Yoshimoto, K., Sato, H., and Ohtake, M., 1993, Frequencydependent attenuation of P and S waves in the Kanto area, Japan, based on the coda-normalization method, Geophysical Journal International, 114, Zeng, Y., Su, F., and Aki, K., 1991, Scattering wave energy propagation in a random isotropic scattering medium; 1, Theory, Journal of Geophysical Research, 96,