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Sea surface temperature record off central Japan since the Last Glacial Maximum using planktonic foraminiferal Mg/Ca thermometry
Author(s) -
Sagawa Takuya,
Toyoda Kazuhiro,
Oba Tadamichi
Publication year - 2006
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.941
Subject(s) - last glacial maximum , geology , globigerina bulloides , foraminifera , oceanography , glacial period , sea surface temperature , water mass , paleoceanography , holocene , seawater , climatology , paleontology , benthic zone
We conducted paired measurements of the Mg/Ca ratio and δ 18 O of planktonic foraminifera, Globigerina bulloides , from a sediment core (MD01‐2420) off central Japan in the northwest Pacific, to reconstruct current movements since the Last Glacial Maximum (LGM). These methods make it possible to determine the magnitude and timing of the sea surface temperature (SST) changes and to reconstruct the variations of the past seawater δ 18 O (δ 18 Ow) off central Japan. The amplitude of Mg/Ca‐based SST changes between the Holocene and the LGM was about 10°C. The strong resemblance of the SSTs estimated from both methods, Mg/Ca‐based and δ 18 O‐based, suggests that the SST changes were caused primarily by latitudinal displacement of the Kuroshio–Oyashio currents and no distinct change in the carbonate dissolution of the core. The southward migration of the water mass was 5–6° in latitude at the LGM. The values for regional δ 18 Ow changes, which were obtained by subtracting the ice volume contribution from the calculated δ 18 Ow, describe the millennial‐scale water mass migration over the last 30 kyr. Copyright © 2005 John Wiley & Sons, Ltd.