Open AccessSeasonal and interannual variation in Santa Barbara Basin water temperatures observed in sediment trap foraminiferal Mg/Ca
Author(s) -
Pak Dorothy K.,
Lea David W.,
Kennett James P.
Publication year - 2004
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2004gc000760
Subject(s) - globigerina bulloides , sediment trap , geology , oceanography , sediment , temperate climate , paleoceanography , water column , foraminifera , geomorphology , ecology , benthic zone , biology
We have generated a Santa Barbara Basin sediment trap Mg/Ca record to evaluate culture‐based calibration equations for the temperate/subpolar planktonic foraminiferal species Globigerina bulloides and Neogloboquadrina pachyderma (dextral). G. bulloides and N. pachyderma Mg/Ca are significantly correlated with seasonal variations in temperature of the near‐surface and subthermocline depths, respectively. The average deviation between Mg‐based and δ 18 O ‐based temperature estimates is ±0.6°C for G. bulloides and ±0.8°C for N. pachyderma . Differences between Mg‐derived temperatures and instrumental temperatures may be due to cleaning methods, environmental factors such as seasonal variations in foraminiferal depth habitats, or possible secondary effects on Mg/Ca. Core‐top Mg/Ca of both G. bulloides and N. pachyderma is in excellent agreement with average values from the sediment trap, lending strong support for the interpretation of downcore Mg/Ca from these species as annual average near‐surface and thermoclinal temperatures.