Webinaire GM/LGO de Thibaut Barreyre (KG Jebsen Centre for Deep Sea Research, University of Bergen)

Stressed Smokers Under Pressure:

Observing Oceanic and Crustal Forces on Hydrothermal Systems

 

The global Mid-Ocean Ridge contains thousands of deep-sea hot springs extracting 10% of the Earth’s total internal heat, generating massive seafloor metal sulfide accumulations, and fueling a ‘deep biosphere’ of ancient microorganisms, likely the first to emerge on Earth. Economic interest in seafloor hydrothermal systems is increasing rapidly in the world, yet the how these systems persist, function and respond to external oceanic and crustal forces remain poorly understood. Recent studies provide strong evidence of high variability in hydrothermal flow rate and temperature over a wide range of spatial and temporal scales, suggesting that hydrothermal systems respond to sub-surface processes such as earthquakes, eruptions, dissolution/precipitation of hydrothermal minerals and tidal loading of the oceanic crust. Understanding the coupling between sub-surface flow and oceanic and crustal conditions is fundamental for assessing energy budget and transport for deep-sea-relevant resources, and has implications for revealing the details of hydrothermal/volcanic linkages at vent fields essentially anywhere on the global Mid-Ocean Ridge. We Examine time-series data sets of key physical parameters (temperature, seismicity, tidal loading) in hot-spring fluids, using state-of-the-art spectral analysis and theoretical poroelastic and thermal models to illuminate the origin, patterns and cause-and-effect relationships in hydrothermal flow response to ocean and crustal phenomena.