HR: 0830h
AN: S21E-0380    [PDF]
TI: Regional Variations in the Earth's upper inner core
AU: * Stroujkova, A
EM: ana_s@juno.com
AF: University of Connecticut, Department of Geology and Geophysics 354 Mansfield Rd, Storrs, CT 06269 United States
AU: Cormier, V F
EM: v.cormier@comcast.net
AF: University of Connecticut, Department of Geology and Geophysics 354 Mansfield Rd, Storrs, CT 06269 United States
AB: Strong regional variations in seismic velocity and attenuation have been observed in the uppermost layer of the inner core. Different studies suggest hemispherical differences within this transitional layer, with eastern hemisphere faster than the western (e.g. Garcia, 2002; Wen and Niu, 2002). The scale and the depth dependence of the heterogeneities are still in debate. In order to systematically study smaller scale heterogeneities we selected a data set of PKIKP and PKiKP phases with epicentral distances between 120\deg and 140\deg. The upper layer of the inner core was divided into `bins' and the seismograms were gathered into these bins according to the ray turning points. After correcting for source, site and propagation effects we stacked traces with close epicentral distance within each bin to improve signal-to-noise ratio. Finally we performed full 3D modeling of the obtained waveforms.
DE: 7200 SEISMOLOGY
DE: 7207 Core and mantle
DE: 8115 Core processes (1507)
SC: Seismology [S]
MN: 2003 Fall Meeting