Imaging Structure at and Near Upper Mantle Discontinuities using a Generalized Radon Transform
Abstract
We apply a generalized Radon transform (GRT) to SS waves reflected at the 410 and 660 km seismic discontinuities in order to image and characterize the interfaces. The GRT assumes both specular and non-specular reflections from scattering points, utilizing the main seismic signal as well as what is commonly considered noise. Thousands of seismograms image single scattering points along a vertical profile, amplifying weak signals without relying on the accuracy of the forward model or background velocity profile. Here we present the result of a test of the GRT using synthetic data and compare it with a preliminary GRT analysis of real data. Using broad-band SS data with bounce points in a 20 by 20 degree bin centered at 35 latitude, 175 longitude, we find that, compared to conventional stacking techniques, the GRT strongly enhances the visibility of the SS precursors. GRT results are used to characterize the regularity of the transitions, leading to quantitative estimates of variations in temperature and composition. Theoretical velocity profiles across the 410 and 660 provide a reference for interpretation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2005
- Bibcode:
- 2005AGUFMDI41A1249L
- Keywords:
-
- 7203 Body waves;
- 7208 Mantle (1212;
- 1213;
- 8124)