Bayani Cardenas

Ridge to reef volcanic hydrogeology: submarine groundwater in the world’s most biodiverse coasts

Bayani Cardenas – Jackson School of Geosciences, The University of Texas at Austin

Abstract

Water flows from land to the ocean not only through rivers and estuaries but also below-ground through coastal and submarine aquifers. While the global fresh submarine groundwater discharge (SGD) is less than nutrient inputs are 25% of riverine inputs. This land-ocean connectivity is important for sensitive ecosystems such as coral reefs if the groundwater we present the interesting but in the Philippines which has been coral reefs provide for local communities. We studied coastal and submarine thermal springs associated with high fluxes of acidic waters and carbon dioxide, some of which are within or close to thriving coral reefs. The SGD fluxes are amongst the largest in the world and the SGD carbon dioxide fluxes overwhelm coastal carbon budgets. The presentation delivers explanations for the high SGD, discussing the mechanics and different sources and pathways of water, by bringing together multiple lines of evidence from different methods including deep diving, drones, novel sensors, geochemical tracers, thermal remote sensing, and modeling.