HR: 17:15h
AN: T24C-06    [Abstracts]
TI: Crustal Thickness Variations in the Aegean Region and its Implications for the Extension of Continental Crust
AU: * Zhu, L
EM: lupei@eas.slu.edu
AF: Department of Earth and Atmospheric Sciences, Saint Louis University, 3507 Laclede Ave., St Louis, 63144 United States
AU: Mitchell, B
EM: bjmitch@eas.slu.edu
AF: Department of Earth and Atmospheric Sciences, Saint Louis University, 3507 Laclede Ave., St Louis, 63144 United States
AU: Akyol, N
EM: nihal.akyol@deu.edu.tr
AF: Department of Geophysics, Dokuz Eylul University, Boca, Izmir, 00000 Turkey
AU: Cemen, I
EM: icemen@okstate.edu
AF: School of Geology, Oklahoma State University, OSU, Stillwater, 74078 United States
AU: Kekovali, K
EM: kekovali@boun.edu.tr
AF: Kandilli Observatory and Earthquake Research Institute, Bogazici University, Istanbul, 00000 Turkey
AB: We installed five broadband and 45 short-period temporary seismic stations, distributed partly as a dense, 100-km-long, N-S linear array and partly as a regional network, throughout the Menderes Massif of western Turkey in order to study crust/upper mantle structure and seismicity. In this study, we have combined teleseismic waveform data from these stations with several permanent seismic stations to determine crustal thickness variations in the Aegean region. Receiver function studies at 7 broadband stations, using the H-kappa stacking method, have yielded crustal thicknesses and Vp/Vs ratios over a broad region of the Aegean. A more detailed crustal image was obtained in the central Menderes Massif where we applied CCP stacking to receiver functions obtained from the N-S linear array. The results show a general trend of westward crustal thinning from 36 km in central Anatolia, to 28-30 km in the central Menderes Massif, to 25 km beneath the Aegean Sea. They also indicate that crustal thinning in the Aegean is not uniform in the N-S extensional direction. The crust is thinner in the Menderes Massif (28 to 30 km of crustal thicknesses) and the Cyladic Massif (25 to 26 km) than in surrounding regions where crustal thicknesses are 32-34 km. The long-lived elevated Moho under the metamorphic core complexes suggests that the lower crust in the Aegean region is at least three times stronger than that in the Basin and Range Province, where the Moho is much flatter.
DE: 7203 Body waves
DE: 7205 Continental crust (1219)
DE: 8109 Continental tectonics: extensional (0905)
SC: Tectonophysics [T]
MN: Fall Meeting 2005