skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Marine biogeochemistry of mercury

Abstract

Noncontaminating sample collection and handling procedures and accurate and sensitive analysis methods were developed to measure sub-picomolar Hg concentrations in seawater. Reliable and diagnostic oceanographic Hg distributions were obtained, permitting major processes governing the marine biogeochemistry of Hg to be identified. Mercury concentrations in the northwest Atlantic, central Pacific, southeast Pacific, and Tasman Sea ranged from 0.5 to 12 pM. Vertical Hg distributions often exhibited a maximum within or near the main thermocline. At similar depths, Hg concentrations in the northwest Atlantic Ocean were elevated compared to the N. Pacific Ocean. This pattern appears to result from a combination of enhanced supply of Hg to the northwest Atlantic by rainfall and scavenging removal along deep water circulation pathways. These observations are supported by geochemical steady-state box modelling which predicts a relatively short mean residence time for Hg in the oceans; demonstrating the reactive nature of Hg in seawater and precluding significant involvement in nutrient-type recyclic. Evidence for the rapid removal of Hg from seawater was obtained at two locations. Surface seawater Hg measurements along 160/sup 0/ W (20/sup 0/N to 20/sup 0/S) showed a depression in the equatorial upwelling area which correlated well with the transect region exhibiting low /supmore » 234/Th//sup 238/U activity ratios. This relationship implies that Hg will be scavenged and removed from surface seawater in biologically productive oceanic zones. Further, a broad minimum in the vertical distribution of Hg was observed to coincide with the intense oxygen minimum zone in the water column in coastal waters off Peru.« less

Authors:
Publication Date:
Research Org.:
Connecticut Univ., Storrs (USA)
OSTI Identifier:
6621611
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; MERCURY COMPOUNDS; BIOGEOCHEMISTRY; SEAWATER; ISOTOPE RATIO; AQUATIC ECOSYSTEMS; ATLANTIC OCEAN; PACIFIC OCEAN; SPATIAL DISTRIBUTION; THORIUM 234; URANIUM 238; WATER CHEMISTRY; ACTINIDE ISOTOPES; ACTINIDE NUCLEI; ALPHA DECAY RADIOISOTOPES; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CHEMISTRY; DAYS LIVING RADIOISOTOPES; DISTRIBUTION; ECOSYSTEMS; EVEN-EVEN NUCLEI; GEOCHEMISTRY; HEAVY NUCLEI; HYDROGEN COMPOUNDS; ISOTOPES; NUCLEI; OXYGEN COMPOUNDS; RADIOISOTOPES; SEAS; SURFACE WATERS; THORIUM ISOTOPES; URANIUM ISOTOPES; WATER; YEARS LIVING RADIOISOTOPES; 520101* - Environment, Aquatic- Basic Studies- Radiometric Techniques- (-1989)

Citation Formats

Gill, G A. Marine biogeochemistry of mercury. United States: N. p., 1986. Web.
Gill, G A. Marine biogeochemistry of mercury. United States.
Gill, G A. 1986. "Marine biogeochemistry of mercury". United States.
@article{osti_6621611,
title = {Marine biogeochemistry of mercury},
author = {Gill, G A},
abstractNote = {Noncontaminating sample collection and handling procedures and accurate and sensitive analysis methods were developed to measure sub-picomolar Hg concentrations in seawater. Reliable and diagnostic oceanographic Hg distributions were obtained, permitting major processes governing the marine biogeochemistry of Hg to be identified. Mercury concentrations in the northwest Atlantic, central Pacific, southeast Pacific, and Tasman Sea ranged from 0.5 to 12 pM. Vertical Hg distributions often exhibited a maximum within or near the main thermocline. At similar depths, Hg concentrations in the northwest Atlantic Ocean were elevated compared to the N. Pacific Ocean. This pattern appears to result from a combination of enhanced supply of Hg to the northwest Atlantic by rainfall and scavenging removal along deep water circulation pathways. These observations are supported by geochemical steady-state box modelling which predicts a relatively short mean residence time for Hg in the oceans; demonstrating the reactive nature of Hg in seawater and precluding significant involvement in nutrient-type recyclic. Evidence for the rapid removal of Hg from seawater was obtained at two locations. Surface seawater Hg measurements along 160/sup 0/ W (20/sup 0/N to 20/sup 0/S) showed a depression in the equatorial upwelling area which correlated well with the transect region exhibiting low /sup 234/Th//sup 238/U activity ratios. This relationship implies that Hg will be scavenged and removed from surface seawater in biologically productive oceanic zones. Further, a broad minimum in the vertical distribution of Hg was observed to coincide with the intense oxygen minimum zone in the water column in coastal waters off Peru.},
doi = {},
url = {https://www.osti.gov/biblio/6621611}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 1986},
month = {Wed Jan 01 00:00:00 EST 1986}
}

Thesis/Dissertation:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this thesis or dissertation.

Save / Share: