The New England Shelf Hydrogeology Expedition (“Proposed Action”) is an investigation to be funded by the U.S. National Science Foundation (NSF) and International Ocean Drilling Programme to understand the sources, distribution, and movement of freshwater beneath the seafloor offshore Massachusetts. The Portal now displays the proposed sampling locations for the Expedition. More information about the sampling to be conducted at each station can be viewed by clicking each proposed sampling point.
This map shows proposed sampling locations for the New England Shelf Hydrogeology Expedition, including primary drill sites (purple circles) and alternative drill sites (green circles), along with 2023 All Vessel Transit Counts and Active Renewable Energy Leases. The Available Information window appears when a website user clicks on a proposed sampling location.
NSF prepared a Draft Environmental Assessment (EA) to evaluate potential impacts of the Proposed Action on the environment pursuant to the National Environmental Policy Act (NEPA). The Draft EA is posted for a 30-day public comment period on the NSF website at: www.nsf.gov/funding/environmental-compliance, closing on April 11, 2025. Comments may be submitted via email to: NSFNEPAMV@nsf.gov. Comments received will be addressed in the Final EA.
The Expedition has been in the planning phases for nearly 20 years by an interdisciplinary team that includes researchers from the University of Massachusetts, Woods Hole Oceanographic Institution, USGS Coastal and Marine Science Center, and others. The research plan leverages information from several previous surveys on the Atlantic continental shelf beginning in the 1970s to characterize sediments below the seafloor and obtain samples using drilling and coring.
This study will use a technique called wireline coring, which encompasses a suite of coring tools, to obtain intact cores of sediment up to 550 meters long at 3-4 locations chosen to help constrain the depth and distance from shore of freshwater saturated sediments. The cores will be analyzed to understand the age and chemical composition of freshwater, which can be used to infer source(s), as well as the microbial diversity and activity within the sediments. It is estimated that the New England shelf may contain 1300 cubic km of freshwater; for perspective, the City of New York uses 1.5 cubic km of freshwater per year. Aquifers like the New England shelf could be used in the future as water reserves for densely populated nearshore regions. Offshore freshwater sources occur in many other places globally. The northeast coast of the U.S. is perhaps the best understood example of an offshore freshwater system.
Research activities would include:
- Drilling, from L/B Robert, at three primary sites; an alternate site would also be used if necessary.
- Coring to collect soft sediments.
- Logging would involve installation of a suite of tools to collect measurements within each borehole. This would be a lightweight assembly between 4-5.2 cm in diameter and not exceeding 5 meters in length.
- Borehole observatories may, depending on operational time and pump test success, be installed for a longer period (multiple years) at a maximum of two of the sites. These would measure pressure, temperature, and resistivity. The instrumentation would be installed inside of the borehole, with a command module that rests on the seafloor a couple meters outside of the borehole (it would not float in the water column).
- Supply deliveries (two trips anticipated) by motor vessel M/V Rana Miller and provisions and personnel transfers via helicopter (about 11-12 trips).
For more information:
