DI11C-2621
SS-precursors Imaging of the Mantle Transition Zone based on Finite-Frequency Theory

Monday, 14 December 2015
Poster Hall (Moscone South)
Carlos Alberto Moreno Chaves1,2 and Jeroen Ritsema1, (1)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (2)USP University of Sao Paulo, São Paulo, Brazil
Abstract:
Olivine, the most abundant mineral in mantle rock, undergoes a sequence of pressure-induced phase changes. Given the opposite signs of the Clapeyron slopes, estimates of the depths of the 400-km and 660-km phase changes can be used to constrain temperature variations in the transition zone.

SS-precursor analysis is a classic tool to map the depths of the 410-km and 660-km phase changes. A number of researchers have argued that finite-frequency theory is necessary to accurately model SS-precursors since the sensitivity of SS reflections extends several thousands kilometers beyond the ray-theoretical reflection point. Using a new global data set of SS precursors, we will make a preliminary comparison of 410-km and 660-km maps derived using ray and finite-frequency theories.