More than 90% of the total Earth's carbon is stored at depth. However, our understanding on how this carbon is recycled and affects life on out planet remains largely unconstrained. Among the most important carbon-bearing molecules, methane (CH4) is important because it has a much higher global warming potential with respect to carbon dioxide (CO2). However, the cycling of deep methane inside the Earth has received, surprisingly, little attention. DeepSeep focus on the production and cycling of deep methane produced through the process called "serpentinization", whereby the most abundant rocks on Earth – mantle rocks – react with water to produce a new mineral called serpentine. This process is special because it produces another fundamental fluid phase called molecular hydrogen, or dihydrogen (H2), which is nowadays central in green energy strategies. When serpentinization produces dihydrogen, carbon is converted to methane. The resulting geological fluids, rich in dihydrogen and methane, are among the least explored fluids of deep Earth processes, even though they may have disproportionate effects of global carbon cycling and may have played a key role in the emergence of life on our planet and potentially elsewhere.
DeepSeep aims at identifying the processes, chemical features, and fluxes of dihydrogen and methane produced through the process of serpentinization in the deep Earth today and in deep time, and how these fluids may have contributed to deep subsurface biosphere processes on Earth and potentially beyond.
