Teh-Ru (Alex) Song joined DTM as a Carnegie Fellow on 2 July. Song received his Ph.D. in 2006 at the Seismological Laboratory at Caltech, where he worked on broadband modeling of mantle structure and great earthquakes through studies of mantle triplications, waveform diffraction patterns, and Earth's normal modes. He also studied spatial variations in the occurrences of subduction zone earthquakes using gravity and topography.

At DTM, Song plans to focus on the modeling of broadband waveforms to determine slab structure--essential information for deciphering the thermal state of subducted lithosphere, its water budget, continental crustal growth, and the occurrence of intermediate-depth earthquakes. In particular, he will be focusing on the flat subduction zones of southwestern Japan and central Chile and on the steep subduction zones in northeastern Japan and Alaska.

Song will also be working to validate the hypothesis that large seismic moment release during great subduction zone earthquakes occur primarily at regions of low gravity and topography in the forearcs, whereas little or no seismic moment release occurs in regions of gravity and topographic highs in the forearcs. Song plans to examine the 2001 Peru great earthquake, determining whether the slip model constructed from variations in gravity and topography in the forearc can explain the seismic waveform data.