Temporal variability of the stability field of methane hydrates in the oceans

Climate change is mainly monitored at the Earth's surface. However, it is well known that as partof ongoing climate change, ocean circulation is also changing, and therefore the ocean floor isalso subject to temperature changes.In this study, the depth of the global methane hydrate stability zone was assessed by analyzing itschanges over the period from 1993 to 2018 to investigate the effect of climate change on thestability of methane hydrates.Indeed, seafloor sediments are often permeated by a methane hydrate phase, the stability ofwhich depends on the pressure and temperature field, among other parameters, and any changesin temperature conditions near the seafloor can bring the methane hydrate into unstableconditions.The data needed for the assessment of methane hydrate stability were obtained from The GlobalOcean Physics Reanalysis data set (GLORYS12V1), produced under the European CopernicusMarine Environment Monitoring Service (CMEMS), and GEBCO- The General Bathymetric Chartof the Oceans. The data were then processed with original data processing software developed inFortran and Python languages.A quantitative estimate of the amount of methane released into ocean masses by the dissociationof methane hydrate in shallow sediments over the period under consideration was also obtained.The release of large amounts of methane could have an impact on submarine geological hazards,such as submarine landslides, and the eventual reaching of the atmosphere by methane wouldreinforce ongoing climate change.