{"id":191042,"date":"2025-08-18T11:50:41","date_gmt":"2025-08-18T15:50:41","guid":{"rendered":"https:\/\/web.uri.edu\/gso\/?p=191042"},"modified":"2025-08-18T11:50:42","modified_gmt":"2025-08-18T15:50:42","slug":"how-did-freshened-water-end-up-beneath-the-seafloor-sediment-collected-by-scientists-may-reveal-answers","status":"publish","type":"post","link":"https:\/\/web.uri.edu\/gso\/news\/how-did-freshened-water-end-up-beneath-the-seafloor-sediment-collected-by-scientists-may-reveal-answers\/","title":{"rendered":"How did freshened water end up beneath the seafloor? Sediment collected by scientists may reveal answers"},"content":{"rendered":"\n

URI Professor Rebecca Robinson is studying freshened water extracted from unprecedented scientific ocean drilling operation<\/h2>\n\n\n\n

August 18, 2025
<\/h4>\n\n\n\n

How did freshened water end up beneath the New England Shelf miles offshore, how long has it been there, and how much of it exists?<\/p>\n\n\n\n

Rebecca Robinson<\/a>, a professor at GSO, is attempting to answer those questions by studying samples collected from three sites off the coast of Nantucket.<\/p>\n\n\n\n

Robinson was one of three chief scientists to lead a multi-national, multi-disciplinary team of 41 researchers on the New England Shelf Hydrogeology<\/a> expedition. After 74 days offshore, the team returned in August with water and sediment samples\u2014in the form of 718 cores measuring more than 871 total meters\u2014to be analyzed in the researchers\u2019 respective labs.<\/p>\n\n\n

\n
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From left, geochemists Rebecca Robinson, Sara Polanco, and Bryce Mitsunuga discuss a sample allocation plan in the Geochem container. (Photo by Maryalice Yakutchik, ECORD IODP\u00b3)<\/figcaption><\/figure>\n<\/div>\n\n\n

\u201cSampling of this offshore freshened groundwater to the extent that we can make comprehensive geochemical assessments of its history, including its age, is unprecedented in scientific ocean drilling,\u201d said Robinson.<\/p>\n\n\n\n

The salinity levels of sediments below the seafloor are typically close to those in the overlying ocean, yet offshore New England, the subseafloor contains an unusually large reservoir of freshened water.<\/p>\n\n\n\n

\u201cThe sheer freshness of the water, which was close to drinking water limits, was a surprise to me,\u201d said Robinson. \u201cI didn\u2019t think freshened meant to the level of oceanic salinities, but I also didn\u2019t think it would be so close to what we get out of the taps.\u201d<\/p>\n\n\n\n

The expedition was organized by the European Consortium for Ocean Research Drilling as part of the International Ocean Drilling Programme<\/a> (IODP\u00b3). Using a 185-foot-long liftboat equipped with a small drilling rig, 50,000 liters of water was pumped from several different depths.<\/p>\n\n\n

\n
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British Geological Survey hydrogeologist Rachel Bell, left, discusses groundwater sampling logistics in front of the sampling manifold with co-chief scientist Rebecca Robinson. (Photo by Maryalice Yakutchik, ECORD IODP\u00b3)<\/figcaption><\/figure>\n<\/div>\n\n\n

\u201cIt was a challenge to pump significant amounts of groundwater out of the wells without destabilizing them,\u201d said Robinson. \u201cTo prevent a column of sediment from collapsing, we had to be strategic about where we were pumping, the flow rate through the equipment, and where we placed our equipment. These were variables we learned to optimize.\u201d<\/p>\n\n\n\n

Robinson was pleased with the results of the drilling operation.<\/p>\n\n\n\n

\u201cI am thrilled with our success in sampling such difficult formations and with the astonishing amount of water we were able to recover for science,\u201d said Robinson.<\/p>\n\n\n\n

Robinson will study the origins and history of the nitrogen in the groundwater by examining the composition of the samples in her lab.<\/p>\n\n\n\n

\u201cWe will study the nitrogen cycling of the water and how it is impacted by the freshened water,\u201d said Robinson. \u201cAll organisms need nitrogen for life, so its cycling marks different types of microbial processing that occurs. Learning what happens along its flow path can tell us something about its history.\u201d<\/p>\n\n\n\n

Robinson will also measure the concentrations and the isotopic composition of nitrogen using an isotope ratio mass spectrometer. The age of the water will be measured by other researchers using radiogenic isotopes, such as carbon-14 and helium-4.<\/p>\n\n\n\n

The other two chief scientists on the expedition were Professor Brandon Dugan of the Colorado School of Mines and Professor Karen Johannesson of the University of Massachusetts Boston. The full science team will convene at the University of Bremen\u2019s core repository in Bremen, Germany in January and February 2026 to further examine the cores, collect more data, and write preliminary reports about the initial findings.<\/p>\n\n\n\n

The cores will be archived and made accessible for further scientific research for the scientific community after a one year-moratorium period. All expedition data will be open access and resulting outcomes will be published.<\/p>\n\n\n\n

The expedition was co-funded by IODP\u00b3 and the National Science Foundation.<\/p>\n","protected":false},"excerpt":{"rendered":"

URI Professor Rebecca Robinson is studying freshened water extracted from unprecedented scientific ocean drilling operation<\/p>\n","protected":false},"author":4762,"featured_media":191043,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[79],"tags":[],"class_list":["post-191042","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts\/191042","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/users\/4762"}],"replies":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/comments?post=191042"}],"version-history":[{"count":1,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts\/191042\/revisions"}],"predecessor-version":[{"id":191044,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts\/191042\/revisions\/191044"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/media\/191043"}],"wp:attachment":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/media?parent=191042"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/categories?post=191042"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/tags?post=191042"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}