Kajita, Hiroto; Suganuma, Yusuke; Haneda, Yuki; Okada, Makoto; Yamamoto, Masanobu; Seki, Osamu; Ohkouchi, Naohiko: Alkenone sea surface temperature from the Chiba Composition Section [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.971475 (dataset in review)
Abstract:
This study displays the high-time resolution of paleo-sea surface temperature (SST) covering the marine isotope stage (MIS) 19 based on the unsaturation ratio of long-chain alkenones (UK'37) retrieved from the Chiba Composition Section (CbCS), central Japan. The CbCS consists of five sections: the Yoro River (35°17.41N; 140°08.48E), Yoro-Tabuchi (35°17.41N; 140°08.49E) and Urajiro (35°16.85N; 140°07.47E) sections. A total of 149 samples were processed for biomarker analyses from the Yoro-Tabuchi (ID: TB2-xx), Yoro River (ID: YT-xxx and TB-xxx), and Urajiro (ID: YW-xxx) sections of the CbCS. Please see Haneda et al. (2020, doi:10.1016/j.epsl.2019.115936) for the sample stratigraphy.
After the surface was cleaned ultrasonically with ethanol, it was freeze-dried and ground into a fine powder. The powdered sediment (6-7 g) was extracted via ultrasonication with dichloromethane, dichloromethane/methanol (1:1, v/v), and methanol. The combined supernatant was dried under N2 gas and extracted with n-hexane from distilled water to obtain the neutral components. The extracted lipids were separated into four subfractions via silica gel column chromatography. The hydrocarbon fraction was eluted with n-hexane/dichloromethane (95:5, v/v). Then, the ketone fraction was eluted with n-hexane/dichloromethane (1:4, v/v) for alkenone analysis. Then, the ketones' fraction was introduced into a gas chromatograph with a mass-selective detector and a flame ionization detector (model 7890A, Agilent Technology) equipped with a VF-5ms fused silica capillary column (30 m × 0.25 mm internal diameter with 0.25 μm film, Agilent Technology). The oven temperature was programmed as follows: maintained at 40 °C for 2 min, raised to 120 °C at 30 °C/min, raised to 300 °C at 6 °C/min, and maintained at 300 °C for 20 min. Alkenone unsaturation ratios (UK'37) were converted into SSTs (℃) using the following calibration.
SST = (UK'37 - 0.039)/0.034
Supplement to:
Kajita, Hiroto; Suganuma, Yusuke; Haneda, Yuki; Okada, Makoto; Yamamoto, Masanobu; Seki, Osamu; Ohkouchi, Naohiko (submitted): Seasonal Sea Surface Temperature Variations at the Northern Limit of the Kuroshio Current in Marine Isotope Stage 20-18. Geophysical Research Letters
Funding:
Coverage:
Median Latitude: 35.288733 * Median Longitude: 140.138033 * South-bound Latitude: 35.285800 * West-bound Longitude: 140.131300 * North-bound Latitude: 35.290200 * East-bound Longitude: 140.141500
Event(s):
Urajiro * Latitude: 35.285800 * Longitude: 140.131300 * Location: Japan * Method/Device: Outcrop sample (OUTCROP) * Comment: All rock samples were taken from outcrops along the rivers in the Boso Peninsula, Japan
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | Kajita, Hiroto | |||
| 2 | Sample ID | Sample ID | Kajita, Hiroto | |||
| 3 | Latitude of event | Latitude | Kajita, Hiroto | |||
| 4 | Longitude of event | Longitude | Kajita, Hiroto | |||
| 5 | AGE | Age | ka BP | Kajita, Hiroto | According to Suganuma et al. (2018) | Geocode |
| 6 | Sea surface temperature | SST | °C | Kajita, Hiroto | SST, from UK'37 |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
298 data points