Figure F3. Topography and bathymetry of the Papuan Peninsula-Woodlark Basin region with acoustic imagery superimposed in the Basin. The neo-volcanic zone of the spreading center is indicated by the region of strong (dark) acoustic backscatter. Shallow earthquake seismicity (solid circles) and associated focal mechanisms (Abers, 1991; Abers et al., 1997) indicate tensional seismicity as far west as 148°E. See Figure F1 for an explanation of tectonic symbols and place abbreviations.