Volcanic geothermal systems, such as the ones present in Iceland, receive heat and a considerable amount of carbon dioxide (CO2) mostly from the magma. This CO2 is naturally removed from the reservoirs by calcite precipitation, gas emissions towards the atmosphere, and carbon dissolution in groundwater transporting the CO2 further away from the systems.

In the context of boosting carbon capture and storage (CCUS) to reduce the CO2 atmospheric content, Iceland provides some of the best conditions to study at field scale the natural geochemical processes involving CO2 and its mineralization.

Fumaroles in the geothermal area at Krýsuvík in SW-Iceland (Credits: C. Marieni)

Water sampling from the lake Þingvallavatn (Credits: C. Marieni)

Geothermal gas sampling from a well at Hellisheidi – Carbfix project (Credits: C. Marieni)