HR: 16:45h
AN: S14A-04 INVITED    [Abstracts]
TI: Scattering of PKKP and P'P' - a tool for mapping fine-scale mantle heterogeneity
AU: * Rost, S
EM: s.rost@leeds.ac.uk
AF: University of Leeds, School of Earth and Environment Institute of Geophysics and Tectonics, Leeds, LS2 9JT, United Kingdom
AU: Earle, P S
EM: pearle@usgs.gov
AF: U.S. Geological Survey, 1711 Illinois Street, Golden, CO 80401, United States
AU: Foks, L N
EM: ear5nlf@leeds.ac.uk
AF: University of Leeds, School of Earth and Environment Institute of Geophysics and Tectonics, Leeds, LS2 9JT, United Kingdom
AU: Shearer, P M
EM: pshearer@ucsd.edu
AF: Scripps Institution of Oceanography, IGPP 0225 U.C. San Diego, La Jolla, CA 92093, United States
AB: Much of what we know about the Earth's deep internal structure at scale lengths around 10 km comes from teleseismic observations of 1 Hz scattered waves. These waves originate when high-frequency surface or body waves interact with fine-scale volumetric heterogeneity or rough boundary layers. Previous studies used scattered energy related to PKP, PKiKP, and P_diff to identify and map the small-scale structure of the mantle and core. These studies elucidate the mineral-physical and geochemical constitution of the Earth and can help answer questions such as the existence of melt in the Earth's deep interior, the location of geochemical reservoirs, and the fate of subducted crustal and slab material. We use observations of scattered energy related to the core phases PKKP and P'P' to study fine-scale mantle heterogeneities. PKKP and P'P' are maximum travel-time phases with respect to perturbations at their reflection points (either at the core-mantle boundary or at the surface, respectively). Therefore, deep-mantle scattered energy arrives as precursors to the main phases where it can be observed free from the contaminating contribution of crustal scattering. Additionally, the scattered energy arrives over a large distance range in a quiet time window. Scattered PKKP and P'P' waves are sensitive to scatterers at different depths within the mantle and hold promise for development of both one dimensional scattering profiles and three-dimensional maps of fine-scale heterogeneity in the Earth's interior.
DE: 7203 Body waves
DE: 7208 Mantle (1212, 1213, 8124)
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Fall Meeting