Letter abstract
Nature Geoscience 1, 309 - 311 (2008)
Published online: 20 April 2008 | doi:10.1038/ngeo183
Subject Categories: Hydrology, hydrogeology and limnology | Oceanography
Submarine groundwater discharge revealed by 228Ra distribution in the upper Atlantic Ocean
Willard S. Moore1, Jorge L. Sarmiento2 & Robert M. Key2
Submarine groundwater discharge is defined as any flow of water at continental margins from the seabed to the coastal ocean, regardless of fluid composition or driving force1. The flux of submarine groundwater discharge has been hypothesized to be a pathway for enriching coastal waters in nutrients, carbon and metals2. Here, we estimate the submarine groundwater flux from the inventory of 228Ra in the upper Atlantic Ocean, obtained by interpolating measurements at over 150 stations. Only 46%
of the loss in 228Ra from radioactive decay is replenished by input from dust, rivers and coastal sediments. We infer that the remainder must come from submarine groundwater discharge. Using estimates of 228Ra concentrations in submarine groundwater discharge, we arrive at a total flux from submarine groundwater discharge of 2–4
1013 m3 yr-
1, between 80 and 160%
of the amount of freshwater entering the Atlantic Ocean from rivers. Submarine groundwater discharge is not a freshwater flux, but a flux of terrestrial and sea water that has penetrated permeable coastal sediments. Our assessment of the volume of submarine groundwater discharge confirms that this flux represents an important vehicle for the delivery of nutrients, carbon and metal to the ocean.
- Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA
- AOS Program, Princeton University, Princeton, New Jersey 08544, USA
Correspondence to: Willard S. Moore1 e-mail: moore@geol.sc.edu
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
An underground route for the water cycleNature News and Views (18 Apr 1996)
Global pollution measured by lead in mid-ocean sedimentsNature News and Views (25 Mar 1987)
See all 8 matches for News And ViewsRESEARCH
Biological export of shelf carbon is a sink of the global CO 2 cycleNature Article (21 May 1981)
Large groundwater inputs to coastal waters revealed by 226 Ra enrichmentsNature Letters to Editor (18 Apr 1996)
See all 58 matches for Research
