Design of the subsurface observatory at Surtsey volcano, Iceland

A subsurface observatory at Surtsey, Iceland's youngest volcanic island, offers unprecedented insights into microbial life and hydrothermal processes in young basaltic tuff. The 2017 ICDP SUSTAIN Expedition drilled three boreholes through the active hydrothermal system, with one equipped to monitor water-rock interactions and microbial activity under sterile conditions. Using filtered seawater and UV sterilization, researchers maintained a contamination-free environment, enabling experiments at temperatures from 25°C to 125°C—approaching the upper limit of functional life (~121°C). The observatory provides a natural laboratory for studying fluid-rock-microbe interactions over time, with comparisons to 1979 and 2019 drill cores offering a 50-year perspective on hydrothermal evolution. This design bridges field observations and experimental validation, advancing understanding of submarine microbial processes.

Türke, A., Jackson, M. D., Bach, W., Kahl, W.-A., Grzybowski, B., Marshall, B., Gudmundsson, M. T., & Jørgensen, S. L. (2019). Design of the subsurface observatory at Surtsey volcano, Iceland. Scientific Drilling, 25, 57–62. https://doi.org/10.5194/sd-25-57-2019