Sea surface temperature record off central Japan since the Last Glacial Maximum using planktonic foraminiferal Mg/Ca thermometry

• Published in: Journal of Quaternary Science
• Main Authors: Sagawa, Takuya, Toyoda, Kazuhiro, Oba, Tadamichi
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: Oyashio; Pacific; Planktonic foraminifera
• Online Access: http://dx.doi.org/10.1002/jqs.941; http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.941; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.941

Abstract 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.