Planktonic foraminifera in the sea of Okhotsk : population and stable isotopic analysis from a sediment trap
Alderman, Susan E.
MetadataShow full item record
The relationship of planktonic foraminiferal populations and stable isotopes to synoptic sea surface temperatures (SST's) was examined in the Sea of Okhotsk, using sediment trap samples (trap deployed Aug. '90 - Aug. '91; 53°19'N, 149°50'E) and AVHRR satellite sea surface temperature data. Synoptic SST's for the deployment ranged between -1.2 and 14.8°C. Two species dominated total yearly foraminiferal flux: N. pachyderma (left) and G. bulloides, with 57% and 31% of yearly flux, respectively. Calcification depths (from δ180eq. calcite) for these species ranged between 20 and 40 meters. Due to the highly stratified water column in the Sea of Okhotsk, these foraminifera experienced temperatures much colder than SST, and use of standard paleotemperature proxies significantly underestimates SST. The average paleotemperatures calculated from both δ180pachy and δ18Dbull were 5-6°C lower than average synoptic SST. Faunal indicators were consistent with this finding, with the N. pachyderma left-to-right coiling ratios >98% for the entire trap deployment. These ratios would suggest maximum seasonal SST's no greater than 10°C, nearly 5°C colder than the actual sea surface temperature maximum. The results from this study indicate that in highly stratified water columns, standard paleotemperature proxies may yield results as much as 5°C cooler than actual sea surface conditions.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1996
Showing items related by title, author, creator and subject.
Relationship of plankton and marine snow to hydrography and currents on the southwest portion of Georges Bank during June 1997 Du, Qingling (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-06)A key question in biological oceanography is how plankton populations maintain themselves in regions of favorable growth and survival in the face of horizontal transport by ocean currents. Plankton are thought to be ...
Amaral-Zettler, Linda A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1996-09)The Acantharea and the Polycystinea are two classes of sarcodines (Sarcodina) which are exclusively planktonic and occur strictly in oligotrophic marine environments. Although these protists have been the topic of research ...
The influence of differential production and dissolution on the stable isotope composition of planktonic foraminifera Erez, Jonathan (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1978-11)Planktonic foraminifera from plankton tows, sediment traps and sediments from the central North Atlantic were studied in order to understand how they acquire their oxygen and carbon isotope compositions. Shallow dwelling ...