Seafloor mapping with AUV-borne high-resolution bathymetry
AUV-borne high-resolution (HR) bathymetry data are revolutionizing our ability of seafloor mapping and hence our understanding of the Mid-Ocean Ridge (MOR) processes. HR bathymetry data provide great details in fine-scale fault systems with resolutions of 0.5-5 m, by a factor of 20-100 times of conventional shipborne bathymetry data. In addition, an unexpected black-smoker hydrothermal vent was recently discovered in the off-axis region (rather than in the more magmatic on-axis region like other vents) of the fast spreading EPR 9°54’N (McDermott et al., 2022), which is associated with a nearby fault (imaged by HR bathymetry data) that provides fluid pathways. There is a challenge to the roles of faults and associated hydrothermal circulation at the MOR, which are largely underestimated and needed to be re-examined by HR bathymetry data systematically and comprehensively. Since MORs accrete young pristine oceanic crusts, they provide a window into early/active-stage fault growth that is essential to understand lithosphere deformation and associated hydrothermal circulation. However, the MOR fault growth model (initiation, propagation, interaction, and linkage of faults) is currently enigmatic due to too few high-quality fault maps. Since our current understanding of fault growth is mostly based on on-land, easy-to-access fault data (Lathrop et al., 2022) and since the new ability of AUV-based seafloor mapping allows us to study fine-scale faults and fault systems on the seafloor almost as straightforwardly as on land, it is timely to explore how MOR faults grow in seafloor spreading regimes, how lithosphere deforms as it stretches, and how hydrothermal circulation responds to different stages of the fault growth.
Related publications:
Chen Jie, Cannat Mathilde, Tao Chunhui, Sauter Daniel, Munschy Marc (2021). 780 thousand years of upper-crustal construction at a melt-rich segment of the ultraslow spreading Southwest Indian Ridge 50°28’E. Journal of Geophysical Research:Solid Earth.
