  Arc volcanoes, created by magma generated from the dehydration of subducting
slabs, show great variability in their sizes and along-arc spatial
distributions. In this study, we address a fundamental question, namely, how do
subduction zones and volcanic arcs respond to the subduction of ``atypical''
oceanic lithosphere. We investigate the correlation between the geographical
location and volume of arc volcanoes and the subduction of linear oceanic
features, including hotspot tracks, oceanic plateaus, volcanic ridges,
mid-oceanic ridges, arc volcano chains, and fracture zones, around the Pacific
basin. We use multidisciplinary and complementary data sets (topography and
bathymetry, seismology and volcano morphometry), and design new analytical and
data processing methods. We analyze 35 oceanic linear features. The subduction
of three oceanic plateaus and five hotspot chains are clearly associated with
volcanism increase, whereas four hotspot chains are related to volcanic gaps.
We propose that the patterns of volcanism increase or decrease related to these
oceanic features depend on the interplay between chemical (potentially
enhancing melting) and thermo-mechanical (inhibiting melting) effects, and/or
by the variations of the chemical signatures along hotspot chains. The
subduction of volcanic ridges is generally associated with small increases in
arc volcanism, which may be accounted for by the fact that these features are
highly hydrated and therefore promote melt. The subduction of active
mid-oceanic ridges is generally associated with slab windows and arc volcano
gaps. No clear inference is found for the subduction of inactive arc ridges.
