Skip directly to content

Minimize RSR Award Detail

Research Spending & Results

Award Detail

Awardee:UNIVERSITY OF ALASKA FAIRBANKS
Doing Business As Name:University of Alaska Fairbanks Campus
PD/PI:
  • C. Geoffrey Wheat
  • (831) 633-7033
  • wheat@mbari.org
Award Date:03/01/2016
Estimated Total Award Amount: $ 410,471
Funds Obligated to Date: $ 410,471
  • FY 2015=$410,471
Start Date:03/01/2016
End Date:09/30/2018
Transaction Type:Grant
Agency:NSF
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Collaborative Research: Completing North Pond Borehole Experiments to Elucidate the Hydrology of Young, Slow-Spread Crust
Federal Award ID Number:1634025
DUNS ID:615245164
Parent DUNS ID:048679567
Program:Marine Geology and Geophysics
Program Officer:
  • Deborah K. Smith
  • (703) 292-7978
  • dksmith@nsf.gov

Awardee Location

Street:West Ridge Research Bldg 008
City:Fairbanks
State:AK
ZIP:99775-7880
County:Fairbanks
Country:US
Awardee Cong. District:00

Primary Place of Performance

Organization Name:University of Alaska Fairbanks Campus
Street:909 Koyukuk Drive
City:Faribanks
State:AK
ZIP:99775-7880
County:Fairbanks
Country:US
Cong. District:00

Abstract at Time of Award

Seawater circulates through the upper part of the oceanic crust much like groundwater flows through continental aquifers. However, in the ocean this seawater circulation, many times heated by buried magmatic bodies, transports and releases 25% of the Earth's heat. The rate of fluid flow through ocean crust is estimated to be equal to the amount of water delivered by rivers to the ocean. Much of what we know of this subseafloor fluid flow comes from studies in the eastern Pacific Ocean on ocean crust created by medium and fast spreading mid-ocean ridges. These studies indicate that seawater and its circulation through the seafloor significantly impact crustal evolution and biogeochemical cycles in the ocean and affect the biosphere in ways that are just now beginning to be quantified and understood. To expand this understanding, this research focuses on fluid flow of seafloor generated by slow spreading ridges, like those in the Atlantic, Indian and Arctic Oceans because it is significantly different in structure, mineralogy, and morphology than that formed at fast and intermediate spreading ridges. This research returns to North Pond, a long-term; seafloor; fluid flow monitoring site, drilled and instumented by the Ocean Drilling Program in the Atlantic Ocean. This research site was punctured by boreholes in which fluid flow and geochemical and biological samplers have been deployed for a number of years to collect data and samples. It also provides resources for shipboard and on-shore geochemical and biological analysis. Broader impacts of the work include sensor and technology development, which increases infrastructure for science and has commercial applications. It also provides training for students and the integration of education and research at three US academic institutions, one of which is an EPSCoR state (Mississippi), and supports a PI whose gender is under-represented in sciences and engineering. Public outreach will be carried out in conjunction with the Center for Dark Energy Biosphere Investigations. This project completes a long-term biogeochemical and hydrologic study of ridge flank hydrothermal processes on slow-spreading, 8 million year old crust on the western flank of the Mid-Atlantic Ridge. The site, North Pond, is an isolated northeast-trending sediment pond, bounded by undersea mountains that have been studied since the 1970s. During Integrated Ocean Drilling Program Expedition 336 in 2011 and an expedition five months later (2012), sensors, samplers, and experiments were deployed in four borehole observatories drilled into the seafloor that penetrated into volcanic crust, with the purpose of monitoring changes in hydrologic properties, crustal fluid composition and mineral alteration, among other objectives. Wellhead sampling in 2012 and 2014 already revealed changes in crustal fluid compositions; and associated pressure data confirm that the boreholes are sealed and overpressured, reflecting a change in the formation as the boreholes recover from drilling disturbances. This research includes a 13-day oceanographic expedition and use of on-site robotically operated vehicles to recover downhole instrument packages at North Pond. It will allow the sampling of crustal fluids, recovering pressure data, and measuring fluid flow rates. Ship- and shore-based analyses will be used to address fundamental questions related to the hydrogeology of hydrothermal processes on slow-spread crust.

Publications Produced as a Result of this Research

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

Wheat, C. G., T. Fournier, K. Monahan, and C. Paul. "Take the plunge: A STEM Camp centered on seafloor science" Current, the Journal of Marine Education, v.31, 2018, p.2-8.


Project Outcomes Report

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

Seawater flows though the basaltic crust in the ocean just like groundwater flows through permeable formations on continental crust. Millions of wells have been drilled into these permeable aquifers on continental crust. Most wells are used to extract water for drinking or irrigation. Wells also have been used to pump wastes fluids into the crust and aid in the extraction of oil and natural gas. To assess the permeability and properties of these crustal reservoirs many tracer tests have been conducted in which a tracer (chemical or dye) is pumped into one hole and monitored in others. On the basis of the when the tracer arrives, one can characterize the aquifer. However, prior to this experiment, only one hole-to-hole experiment has ever been conducted in the oceanic crust, even though the upper permeable basalt that underlies an impermeable sediment is one of the largest crustal water reservoirs on Earth. This project represents the second hole-to-hole experiment in the oceanic crust.

 

What makes this experiment novel is that it was fully conducted by a remotely operated vehicle (ROV) and it utilized a legacy borehole, one that was drilled and cased into the basaltic crust, but left for future potential work. We deployed a tracer (dissolved cesium) in the legacy borehole and monitored a nearby borehole to detect when the tracer arrived. The tracer arrived within 11 days. This provides constraints for the hydrologic parameters of the oceanic aquifer and means that future expeditions could inject nutrients or potential metabolites to assess reaction pathways and kinetics of reactions within the basaltic crust. The ocean crustal reservoir is home to one of the largest biomes on Earth and one that appears to be slow growing, yet is sustainable for millions of years or potentially much longer.

 

Much of the project focused on the development of technology to conduct the proposed work and the month-long expedition. These technological developments  will make future experiments possible and were incorporated into several hands-on activities for the Seafloor Science and Remotely Operated Vehicle (SSROV) summer camp. The summer camp is a week-long camp for two levels, 3-5th and 6-9th grades. In 2018, 197 campers and 20 high school and college students participated in the camp.


Last Modified: 10/05/2018
Modified by: C. Geoffrey Wheat

For specific questions or comments about this information including the NSF Project Outcomes Report, contact us.