Fig. 1

Bathymetric map of the Hawaiian Islands and the surrounding Pacific Plate. The seismic lines of this study are shown by solid black lines, and yellow circles show the positions of ocean-bottom seismometers (OBSs). Colored lines show the locations of previous active-source seismic surveys around the island chain. Hawaiian Plume-Lithosphere Undersea Melt Experiment (PLUME) station locations are shown by black dots (e.g., Wolfe et al. 2009; Leahy et al. 2010; Laske et al. 2011). Thin white lines indicate seafloor age (in millions of years; from Muller et al. 2008). The black dashed line indicates the axis of the Hawaiian Arch (e.g., Holcomb and Robinson 2004; Ballmer et al. 2011). The North Arch volcanic field, characterized by strong acoustic reflectivity (Normark et al. 1989; Clague et al. 1990, 2002), is indicated by gray shading