“…While the crust of the western Pacific was formed by Jurassic mid‐ocean ridge seafloor spreading, broad areas of the Pacific plate were subjected to Cretaceous volcanism in the form of numerous seamounts and large igneous provinces (Larson, 1991; Stadler & Tominaga, 2015). Most of the large volcanic features are documented by satellite altimetry data, but it is common to observe small seafloor volcanic features using ship multibeam sonar and high‐resolution MCS data (e.g., D. K. Smith & Jordan, 1987, 1988; Stadler & Tominaga, 2015). Furthermore, in addition to extrusive volcanics apparent at the seafloor, seismic profiles provide evidence of subseafloor volcanic features, such as volcanic sills within sediments and upper crust (Abrams et al., 1992; Feng, 2016; Kaneda et al., 2010; Lancelot, Larson, & Fisher, 1990; Lancelot, Larson, & Shipboard Scientific Party, 1990; Mochizuki et al., 2005; Schlanger & Moberly, 1986; Stadler & Tominaga, 2015; Tominaga et al., 2008).…”