Biology Meets Subduction

The team selected Costa Rica as a study site because several other teams have investigated its active volcanoes and subduction zones, providing important contextual data for further exploration. Offshore, the area has been investigated as part of the International Ocean Discovery Program. Onshore, some of the current project’s investigators have already documented a number of the existing conditions where sampling took place.

Carbon is stored in ocean sediments, as well as in Earth’s mantle and crust. Each of these “storage areas” serves as a carbon reservoir. Carbon flux is the term for carbon movement between reservoirs.

Many questions exist about the influence of biological processes on carbon flux. This investigation will help scientists better predict how carbon moves in and out of Earth on a global basis and how that movement is related to biological processes.

Because this project is exploratory, it will improve what we know about how carbon moves, but also is offering vast opportunities for surprising new discoveries. Another unique aspect is that the lead investigators are early career scientists (within seven years of being awarded a PhD), who have aligned themselves with a strong collection of external with collaborators, many of whom are leaders in their field. What this team learns will inform the field of deep carbon science for years to come.

The team visited 25 field sites over the course of 12 days: Poás, Turrialba, and Arenal volcanoes and springs along the Nicoya and Osa peninsulas. Costa Rican scientists will play integral roles in the logistic and scientific success of the field campaign, with Carlos Ramirez from the University of Costa Rica leading the charge. The local team also includes Gino Gonzalez from the University of Costa Rica, and J. Maarten de Moor, Maria Martinez, Monserrat Cascante, and Ricardo Sanchez from the Observatorio Vulcanológico Y Sismológico de Costa Rica, Universidad Nacional, Costa Rica (OVSICORIO-UNA)). Together, the local and international team of investigators conducted different sampling protocols at each of the locations, as described below.

Onsite sampling

Principal Investigator Peter Barry (University of Oxford, UK) and collaborator Patrick Beaudry (Massachusetts Institute of Technology, USA) collected fluid and gas samples in the forearc and arc to distinguish biogenic, thermogenic, and abiotic carbon sources.  

Donato Giovanelli (Earth-Life Science Institute, Japan and Rutgers University, USA) and Karen Lloyd (University of Tennessee, USA) led a team of collaborators that includes Lloyd’s graduate student Katie Fullerton, as well as collaborator Heather Miller (Michigan State University, USA). They combined in situ measurements of biologically relevant geochemistry and metabolic activity with ex situ biochemical and molecular tools to investigate the functional and taxonomic diversity of the microbial community within sediments and fluids in the volcanic arc and forearc.

Daniel Hummer (Southern Illinois University, USA) and J. Marteen de Moor (Universidad Nacional, Costa Rica), Angelo Battaglia (Università degli Studi di Palermo, Italy), Giulio Bini (University of Florence, Italy), and Kayla Iocovino (Arizona State University, USA) measured the complete chemical composition of gases from actively degassing volcanoes using a combination of direct measurement and in situ sampling. Taryn Lopez (University of Alaska Fairbanks, USA) spearheaded this part of the sampling plan and was unable to join the team in the field, but will remain heavily involved in the project moving forward. 

Hummer and de Moor, with collaborators Esteban Gazel and Aristides Alfaro (Virginia Tech, USA), sampled volcanic tephras (solid matter, such as ash, dust, and cinders, that is ejected into the air by an erupting volcano) from Turrialba, Poás, and Arenal volcanoes, which contain abundant olivine phenocrysts with melt and fluid inclusions. 

Collaborator Stephen Turner (Washington University in St. Louis, USA) used sophisticated analytical methods to track fluxes from the slab to the mantle wedge, helping to delineate volatile sources and the proportion of deeply recycled carbon. Kayla Iocovino is working to create a box model describing carbon flux at this convergent margin.

Katie Pratt (University of Rhode Island, USA) documented the expedition, blogging from the field and photographing and filming the team in action. Videographers Marcus Lehmann, Brian Cimaglia, Russ Hollingsworth, and Tom Owens, also joined the expedition and are creating short films about this novel field investigation. 
Additional collaborators not participating in the field, but involved in data and sample analysis, include Mustafa Yucel, Matt Schrenk, Shuhei Ono, Rosario Esposito, David Hilton, Christopher House, Amanda Martino, Elena Manini, Constantino Vitriani, Tomohiro Mochizuki, Mayukpo Nakagawa, and Francesco Regoli. 
Since the sampling expedition is now complete, investigators are sharing samples and conducting additional analyses in many laboratories around the globe. The team expects to report out their results in spring 2018.  Check back here as the results unfold.

Additional collaborators not participating in the field, but involved in data and sample analysis, include Mustafa Yucel, Matt Schrenk, Shuhei Ono, Rosario Esposito, David Hilton, Christopher House, Amanda Martino, Elena Manini, Constantino Vitriani, Tomohiro Mochizuki, Mayukpo Nakagawa, and Francesco Regoli.

Since the sampling expedition is now complete, investigators are sharing samples and conducting additional analyses in many laboratories around the globe. The team expects to report out their results in spring 2018. Check back here as the results unfold.