GeoForschungsZentrum Potsdam
poster/oral: oral
We use precursors to SS and PP waves and PS conversions in the coda of P to map the position of the '410' and '660' in a global and local scale. We see a negative correlation between the thickness of the transition zone and the travel times in the upper mantle. Our conclusion is that there is a correlation between the structure of the transition zone and oceans and continents.
From the absence of PP precursors from the '660' we derive an increased jump in Poisson's ratio at the '660' on a global scale with the result that the '660' is mainly a shear discontinuity. We map the '410' and '660' and additional discontinuities under several permanent broad band stations at subduction zones and hot spots.