NEW: The floating undersea robots known as Mermaids exceed our wildest expectations. Click here for some latest results...
TOMOGRAPHY: There is excellent agreement between the images of the broken-up Farallon plate beneath the western United States, obtained with P and S finite-frequency tomography. The figure shows the P velocity image from Sigloch et al. (2008) and that for S velocity by Tian et al. (2009). Colour indicates depth: anything blue-ish is in the upper mantle.
PREPRINT: With Diego Mercerat we show that cross-correlation travel times vary linearly with variations in the Earth's elastic parameters for changes of up to +/-10%. There is thus no need for nonlinear iterations for much of the mantle. Click here for a preprint.
LECTURE: At the Meeting of the European Seismological Commission I gave my view on where global seismic tomography is heading. Click here for a video and/or a PDF version of my talk.
By now the debate on Banana-doughnut kernels for seismic tomography is a little old, most seismologists accept that we have to use finite frequency methods if we wish to make any progress. But I keep the link because it is still a much-requested item.
Want to learn about finite-frequency tomography? If you do not wish to spend 34 pounds on the book, but also lack the courage to digest all 194 equations in Dahlen, Hung and Nolet (2000), then try this tutorial paper (click on the image).