Modeling the Evolution of Transform Faults: Influence of Mid-Ocean Ridge Spreading Dynamics

Abstract

The role of transform faults, significant plate boundaries located on the seafloor, in influencing and modifying the spreading processes of adjacent mid-ocean ridges has long been a subject of investigation. However, the reciprocal impact of spreading rate and magma supply on the development and demarcation of transform faults has not been fully addressed. Observations from the Atlantic further suggest that long offset transform faults tend to remain stable upon variations in magma supply at the adjacent ridge segments, while shorter transforms are frequently abandoned during axis reorganizations by e.g. propagating ridges. In this study, we developed a three-dimensional model to examine the response of transform faults to variations in magma supply at the adjacent ridges.  In a suite of model runs, we change offset, transform fault rheology, and magma supply to evaluate if shorter transforms are more likely to be abandoned or replaced by non-transform offsets than longer transforms. We confront our modeling insights with observations from the North Atlantic, particularly between latitudes 30°N and 35°N, where the Atlantis, Hayes, and Oceanographer transforms appear to have been stable on long time scales, while the shorter segmentations in between have experienced multiple reorganizations.