Modification of along-ridge topography and crustal thickness by mantle plume and oceanic transform fault at ultra-slow spreading Mohns Ridge

The mantle plumes modify the geophysical and geochemical features along and across mid-ocean ridges. Despite abundant studies of plume-ridge interaction, very few geodynamic studies focus in the Arctic Ocean. The Jan Mayen Hotspot is located at the south end of the Mohns Ridge and offset by the Jan Mayen Transform Fault, which creates an ideal tectonic setting to study plume-ridge-transform fault interaction at ultraslow spreading ridge. Through comprehensive analysis of geophysical observations, we reveal that the seafloor morphology and crustal thickness along the Mohns Ridge systematically decrease northward within a distance of ~370 km to the Jan Mayen Hotspot. Combined with geodynamic modeling, the properties of Jan Mayen mantle plume were estimated, which has a diameter of 100 km, temperature anomaly of 100 °C, and volume flux of 1.4´10⁶ km³/Myr. Additionally, our model results indicate the along-ridge dispersion of plume is not impeded, but slightly enhanced by the transform fault.