Sedimentary nitrogen isotopic ratio as a recorder for surface ocean nitrate utilization

Journal Article · Tue Mar 01 00:00:00 EST 1994 · Global Biogeochemical Cycles; (United States)

DOI:https://doi.org/10.1029/93GB03396· OSTI ID:7226144

Altabet, M A; Francois, R ^[1]

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1. Woods Hole Oceanographic Institution, MA (United States)

The availability of nutrients in the near surface ocean is an important control on primary production, whose variability over geologic time may have altered major biogeochemical cycles. Ocean models have suggested a specific link between glacial/interglacial variations in atmospheric CO2 concentrations and changes in nutrient concentration at the surface of high latitude seas. Isotope ratios have been used to evaluate nutrients in the ocean surface. To test the fidelity with which surface generated isotopic signals are recorded in deep-sea sediments, this study focused on equatorial Pacific ocean and the southern ocean. In both regions large gradients in near surface NO3 concentration and depletion dominate any local temporal variation. Corresponding gradients were found in Nitrogen 15 and compared to sedimentary values. Results indicate that strong near surface N15 gradients are indeed recorded in underlying surface sediments. 55 refs., 10 figs., 1 tab.

• OSTI ID: 7226144
• Journal Information: Global Biogeochemical Cycles; (United States), Vol. 8:1; ISSN 0886-6236
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
NITRATES
ECOLOGICAL CONCENTRATION
NITROGEN 15
SEAS
NUTRIENTS
SEDIMENTS
ISOTOPE RATIO
PACIFIC OCEAN
PALEOCLIMATOLOGY
ISOTOPES
LIGHT NUCLEI
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PALEONTOLOGY
STABLE ISOTOPES
SURFACE WATERS
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)