Deep water cycle

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Related topics Biogeochemistry geochemical cycle chemical cycling environmental chemistry Biosequestration Deep biosphere Ocean acidification acid rain Biogeochemical planetary boundaries
Research groups DAAC GEOTRACES IMBER NOBM SOLAS
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The deep water cycle, or geologic water cycle, involves exchange of water with the mantle, with water carried down by subducting oceanic plates and returning through volcanic activity, distinct from the water cycle process that occurs above and on the surface of Earth.^[1] Some of the water makes it all the way to the lower mantle and may even reach the outer core. Mineral physics experiments show that hydrous minerals can carry water deep into the mantle in colder slabs and even "nominally anhydrous minerals" can store several oceans' worth of water.

The process of deep water recycling involves water entering the mantle by being carried down by subducting oceanic plates (a process known as regassing) being balanced by water being released at mid-ocean ridges (degassing).^[1] This is a central concept in the understanding of the long‐term exchange of water between the Earth's interior and the exosphere and the transport of water bound in hydrous minerals.^[2]