WesternGeco and Schlumberger, as part of the Sumatran Andaman Great Earthquake Research (SAGER) team, contributed to the effort to image the Sumatran seismogenic zone that ruptured on 26 December 2004. Resulting reflection images allow interpretation of the rupture point down to 40 km of depth, providing arguably the best seismic reflection images of a deep subduction zone to date. Early images, generated on the vessel, showed that the subducting mechanism (oceanic crust plus Moho) can be seen down to 12 s two-way traveltime (TWTT). Additional interpretation has shown seismic reflections as deep as 18 s TWTT (50–60 km of depth). This is a rare example of a complete subduction zone system being directly imaged with reflection seismic technology to over 40 km of depth.