BCO-DMO

Award: OCE-1536539

Award Title: Collaborative Research: Completing North Pond Borehole Experiments to Elucidate the Hydrology of Young, Slow-Spread Crust

Outcomes Report

The purpose of this collaborative research project was to study the microscopic life that grows on rocks below the seafloor. This oceanic crust is a massive potential reservoir for life on Earth, but very little is known about the composition of this life and how it impacts the rocks. Upper oceanic crust is primarily composed of basalts, with similar composition to lava rocks on land, and this rock is enriched in elements like iron and sulfur that life might be able to use for chemical energy to grow. In order to study microscopic life below the seafloor, holes were drilled into the ocean crust in 2011 during Expedition 336 of the International Ocean Discovery Program. Observatories were placed into these holes in a similar way to how wells are placed in aquifers on land. Our team inserted a buffet of different sterilized rocks into the observatories and left them there for several years to allow the microscopic life living in this habitat to colonize the experiment surfaces. In 2017 we recovered these experiments to examine the microscopic life that grew on the rocks using microscopic and DNA sequencing techniques. We have also been trying to grow some of the unique microbial groups that have the ability to harness the energy from the iron in the rocks for metabolism. Microscopic analysis revealed a variety of biofilm structures and mineral alteration products that had formed on the rock surfaces, and DNA analysis indicates varying microbial community structure on the different rock types. Although the project has officially ended, analysis of these samples continues, leveraging support from the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI). This project enabled the largest and most diverse recovery of rock colonization experiments done in the marine subsurface, allowing a detailed examination of the microbe-mineral interactions that occur in Earth?s subsurface. Lessons learned from these experiments have relevance for designing approaches for determining if life might exist on the rocky ocean worlds of our Solar System like Europa and Enceladus. During the 2017 cruise, we engaged middle school students in the exploration and science of our project through a ship-to-shore outreach project called 'Adopt A Microbe' (https://sites.google.com/site/adoptamicrobe2017/) run in collaboration with the Girl Scouts of Maine. Last Modified: 12/20/2018 Submitted by: Beth Orcutt

Dataset	Latest Version Date	Current State
16S rRNA gene amplicon sequences from FLOCS experiments at the Juan de Fuca Ridge CORKs during August 2014.	2019-02-20	Final no updates expected
Scanning Electron Microscopy (SEM) photographs of biofilms and mineral alteration products from R/V Atlantis AT39-01 in the North Pond CORK Sites U1382A, U1383C from 2011-2017	2019-02-22	Final no updates expected
CTD data from AT39-01 (North Pond 2017 expedition) from the R/V Atlantis in the central North Atlantic during October 2017	2019-03-07	Final no updates expected
Chronoamperometry data from cathodic poised potential experiments with subsurface crustal samples from CORK borehole observatories at North Pond on the Mid-Atlantic Ridge during R/V Atlantis cruise AT39-01	2019-10-30	Final no updates expected
Metadata for cathodic poised potential experiments with subsurface crustal samples from CORK borehole observatories at North Pond on the Mid-Atlantic Ridge during R/V Atlantis cruise AT39-01	2019-10-30	Final no updates expected
Cyclic voltametry data from cathodic poised potential experiments with subsurface crustal samples from CORK borehole observatories at North Pond on the Mid-Atlantic Ridge during R/V Atlantis cruise AT39-01	2020-02-03	Final no updates expected
16S rRNA gene amplicon sequences from cathodic poised potential experiments with subsurface crustal samples from CORK borehole observatories at North Pond on the Mid-Atlantic Ridge during R/V Atlantis cruise AT39-01	2019-10-30	Final no updates expected
Scanning Electron Microscopy (SEM) photographs of biofilms on indium tin oxide electrodes from cathodic poised potential experiments with subsurface crustal samples from CORK borehole observatories at North Pond on the Mid-Atlantic Ridge during R/V A	2020-02-03	Final no updates expected

Award: OCE-1536539

Award Title: Collaborative Research: Completing North Pond Borehole Experiments to Elucidate the Hydrology of Young, Slow-Spread Crust

Funding Source: NSF Division of Ocean Sciences (NSF OCE)

Program Manager: Barbara Ransom

Outcomes Report

People

Award: OCE-1536539

Award Title: Collaborative Research: Completing North Pond Borehole Experiments to Elucidate the Hydrology of Young, Slow-Spread Crust

Funding Source: NSF Division of Ocean Sciences (NSF OCE)

Program Manager: Barbara Ransom

Outcomes Report

People