Nonhomogeneous seawater Sr isotopic composition in the coastal oceans : a novel tool for tracing water masses and submarine groundwater discharge
MetadataShow full item record
Here we present high-precision (2σ = ±3 ppm) 87Sr/86Sr measurements in coastal waters, together with salinity, to evaluate water mass mixing and the influence of submarine groundwater discharge (SGD) in coastal waters and marginal seas. Nonhomogeneous Sr isotopic variations in water columns were documented in the Southern Okinawa Trough (SOT), South China Sea, and Kao-ping Canyon (KPC), where seawater 87Sr/86Sr varied up to 70 ppm. Seawater Sr isotopic composition changes only slightly in the upper 200 m of the SOT but was detectable and highly correlated with salinity, indicating a mixing between radiogenic North Pacific Tropical Water (high 87Sr/86Sr and high salinity) at 100–150 m and a less radiogenic component with low 87Sr/86Sr and low salinity at ∼200 m. Vertical profiles of seawater 87Sr/86Sr along the KPC show significant variations, suggesting dynamic mixing affected by continental inputs (i.e., river runoff and SGD) in this region. These results highlight the potential use of seawater Sr isotopes as a powerful tracer for determining mixing ratios and the dynamic mixing of oceanic water masses, especially in coastal and marginal seas.
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 12 (2011): Q05002, doi:10.1029/2010GC003372.
Suggested CitationGeochemistry Geophysics Geosystems 12 (2011): Q05002
Showing items related by title, author, creator and subject.
Investigating boron isotopes for identifying nitrogen sources supplied by submarine groundwater discharge to coastal waters Tamborski, Joseph; Brown, Caitlin; Bokuniewicz, Henry J.; Cochran, J. Kirk; Rasbury, E. Troy (Frontiers Media, 2020-08-11)Stable isotopes of oxygen, nitrogen, and boron were used to identify the sources of nitrate (NO3–) in submarine groundwater discharge (SGD) into a large tidal estuary (Long Island Sound, NY, United States). Potential ...
The magnitude and origin of groundwater discharge to Eastern U.S. and Gulf of Mexico coastal waters Befus, Kevin Martin; Kroeger, Kevin D.; Smith, Christopher G.; Swarzenski, Peter W. (John Wiley & Sons, 2017-10-28)Fresh groundwater discharge to coastal environments contributes to the physical and chemical conditions of coastal waters, but the role of coastal groundwater at regional to continental scales remains poorly defined due ...
Global estimate of submarine groundwater discharge based on an observationally constrained radium isotope model Kwon, Eun Young; Kim, Guebuem; Primeau, Francois W.; Moore, Willard S.; Cho, Hyung-Mi; DeVries, Timothy; Sarmiento, Jorge L.; Charette, Matthew A.; Cho, Yang-Ki (John Wiley & Sons, 2014-12-03)Along the continental margins, rivers and submarine groundwater supply nutrients, trace elements, and radionuclides to the coastal ocean, supporting coastal ecosystems and, increasingly, causing harmful algal blooms and ...