Mid-ocean ridge jumps: Impacts, classification, and mechanisms

Abstract

Mid-ocean ridge jumps (RJs) are key reorganization events in mid-ocean ridge (MOR) systems when a MOR segment shifts to a neighboring location, leaving the old segment inactive. Despite their global significance, current research predominantly concentrates on individual RJs or large jumps, lacking a systematic examination of RJ events. While many studies emphasize hotspot-ridge interactions as a primary driver, earlier work has also highlighted the role of plate motion changes and the potential for synergistic interactions between these two processes. This underscores the need for a more comprehensive investigation. This study systematically investigates RJs across 33 global sites, analyzing over 50 individual RJ events. We initially classify these events into three categories based on their geological settings: (1) in pure divergent settings, (2) in shear zones, and (3) in subduction-influenced zones. Our analysis elucidates the fundamental tectonic processes governing these events, identifying off-axis mantle upwellings and plate motion changes as the primary drivers of RJs across all settings. While mantle upwellings contribute to vertical movements and the weakening of the lithosphere, plate motion changes realign the horizontal stresses necessary for extensional forces and ultimately determine the final placement of new spreading centers. Rather than operating in isolation, these mechanisms interact synergistically, contributing to the intricate dynamics of RJ events. By reevaluating the significance of RJs on the evolution of MORs, our findings greatly contribute to the knowledge of complex structures within the oceanic domain and enhance our comprehension of Earth's crustal evolution.