Seamount chains and hotspot tracks: Superficially similar, deeply different

Abstract

Nearly 80% of the seafloor extension has not been covered by high-resolution bathymetry, impeding direct observation of seamounts. Nevertheless, lists of seamount location and height at a global scale have been produced using different techniques. In this work four of such databases (publicly available) are compared with each other to assess their differences. Results identify large differences among databases that could have exerted strong influences on models of seamount production and associated geodynamic processes. Despite those differences, it is shown that all databases allow the identification of seamount lines both along the present-day Mid Ocean Ridge (MOR) system and on intraplate settings. Notably, those seamount lines do not coincide with the so-called hotspot tracks that commonly were defined by selectively focusing attention on the larger seamounts. Examination of all the databases also shows that distinction based only on seamount size between seamounts produced at Mid-Ocean Ridge (MOR) environments from those associated with mantle-plum fed-hotspot activity has been overestimated. This, combined with the fact that most seamount lines defined by the available databases can be traced back to past locations of MOR indicates that most of the present-day intraplate linear arrays of seamounts, which include some large seamounts, were not produced by the action of underlying mantle anomalies envisaged in the form of mantle plumes. The evidence presented here calls for a reassessment of the form in which volcanic and tectonic activities are conceptually related to each other.