Sea-level stability over geological time owing to limited deep subduction of hydrated mantle

Liquid surface oceans are a seemingly unique feature of Earth. Long-term, global sea level depends on the balance water fluxes between Earth’s mantle and surface: degassing through volcanism regassing via subduction hydrous minerals. However, overall these at geological timescales remains uncertain. Geological observations suggest stability long-term thus near-steady-state regassing–degassing balance. In contrast, according to current thermopetrological modelling, input H2O inferred from geophysical leads an unequivocal excess relative degassing. Here we use recent experimental high-pressure data natural hydrated peridotites update models reassess calculations into subduction. Our 56 transects show that 15?20 × 108 TgH2O every million years yields limited 2.0?3.5 years. The occurs exclusively lithospheric coldest subducting plates. requantification budget associated with matches estimations suggests levels have been relatively stable over timescales. Accounting for reduces estimated recycled deep during sea-level time, zone modelling.