海面下に着底した東南極氷床の安定性に関する研究

• 研究課題/領域番号: 20J21145
• 研究種目: 特別研究員奨励費
• 配分区分: 補助金
• 応募区分: 国内
• 審査区分: 小区分17030:地球人間圏科学関連
• 研究機関: 東京大学
• 研究代表者: BEHRENS BETHANY 東京大学, 総合文化研究科, 特別研究員(DC1)
• 研究期間 (年度): 2020-04-24 – 2023-03-31
• 研究課題ステータス: 完了 (2022年度)
• 配分額: 3,100千円 (直接経費: 3,100千円); 2022年度: 1,000千円 (直接経費: 1,000千円); 2021年度: 1,000千円 (直接経費: 1,000千円); 2020年度: 1,100千円 (直接経費: 1,100千円)
• キーワード: Antarctica / Beryllium / Ice sheet / Holocene / Tasmania / beryllium isotopes / radiocarbon / glacial cycles / East Antarctica / beryllium / cosmogenic isotopes / glacial discharge

研究開始時の研究の概要

Phase I) Analyze freshwater discharge through ice shelf melt from Wilkes Subglacial Basin, Antarctica, and correlate the data to past climate variability.
Phase II) Collect information about past climate patterns which may have increased Southern Ocean upwelling, leading to warmer surface ocean temperatures and melting of marine-based ice sheets.
Phase III) Determine freshwater output from Aurora Subglacial Basin, Antarctica, to determine any periods of oceanic or atmospheric warming related to climate variations revealed in Phase II which may have affected ice sheet discharge through melting.

研究実績の概要

Phase 1: Preparation of the high resolution Adelie Basin, East Antarctica samples has been completed, and analysis of beryllium isotopes by accelerator mass spectrometry is finished. A manuscript detailing the high resolution dataset is being prepared for submission to a scientific journal.
Phase 2: Additional samples from the Sabrina Coast region of East Antarctica have been analyzed by accelerator mass spectrometer for beryllium isotopes. Comparison to a nearby core at a shallower depth reveal some interesting differences in the data, despite the proximity of the core sites. The results are under discussion with coauthors, and the data was presented at the Japan Geosciences Union meeting and the Geological Society of America meeting in poster form.
Phase 3: Samples from Lake Selina in the West Coast Range of Tasmania have been analyzed by accelerator mass spectrometry, covering the past five marine isotope stages (MIS 1-5). With a greater sample number, it has been interesting to see a stronger climate signal than expected. The results from this analysis were presented at the Geological Society of America meeting as an oral presentation, and the manuscript is complete and under discussion with coauthors. It will shortly be submitted to a scientific journal.

現在までの達成度 (段落)

令和4年度が最終年度であるため、記入しない。

今後の研究の推進方策

令和4年度が最終年度であるため、記入しない。

研究成果

• [雑誌論文] Beryllium isotope variations recorded in the Adelie Basin, East Antarctica reflect Holocene changes in ice dynamics, productivity, and scavenging efficiency (2022)
  • 著者名/発表者名: Behrens Bethany C.、Yokoyama Yusuke、Miyairi Yosuke、Sproson Adam D.、Yamane Masako、Jimenez-Espejo Francisco J.、McKay Robert M.、Johnson Katelyn M.、Escutia Carlota、Dunbar Robert B.
  • 雑誌名: Quaternary Science Advances 巻: 7 ページ: 100054-100054
  • DOI: 10.1016/j.qsa.2022.100054
  • 査読あり / オープンアクセス / 国際共著
• [雑誌論文] Efficient radiocarbon measurements on marine and terrestrial samples with single stage Accelerator Mass Spectrometry at the Atmosphere and Ocean Research Institute, University of Tokyo (2022)
  • 著者名/発表者名: Yokoyama Y., Miyairi Y., Aze T., Sawada C., Ando Y., Izawa S., Ueno Y., Hirabayashi S., Fukuyo N., Ota K., Shimizu Y., Zeng Y., Lan H., Tsuneoka R., Ando K., Nemoto K., Obrochta S., Behrens B., Tam E., Leggett K., Rzeszewicz J., Huang Z., Kondo R., Nagata T.
  • 雑誌名: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 巻: 532 ページ: 62-67
  • DOI: 10.1016/j.nimb.2022.10.006
  • 査読あり / オープンアクセス / 国際共著
• [雑誌論文] Initial measurement of beryllium‐9 using high‐resolution inductively coupled plasma mass spectrometry allows for more precise applications of the beryllium isotope system within the Earth Sciences (2021)
  • 著者名/発表者名: Sproson Adam D.、Aze Takahiro、Behrens Bethany、Yokoyama Yusuke
  • 雑誌名: Rapid Communications in Mass Spectrometry 巻: 35 号: 8 ページ: 1-10
  • DOI: 10.1002/rcm.9059
  • 査読あり / オープンアクセス / 国際共著
• [学会発表] Antarctic Slope Current intensification following Last Glacial Maximum ice retreat (2022)
  • 著者名/発表者名: Bethany C Behrens
  • 学会等名: Japan Geoscience Union
• [学会発表] Climatic and paleomagnetic forcing of beryllium isotope ratios of Lake Selina, Tasmania from 125,000 years ago to the present (2022)
  • 著者名/発表者名: Bethany C Behrens
  • 学会等名: Geological Society of America
  • 国際学会
• [学会発表] Relationship between the Southern Westerly Winds and glacial dynamics at the Sabrina Coast, East Antarctica as determined by beryllium isotope ratios (2022)
  • 著者名/発表者名: Bethany Behrens
  • 学会等名: Geological Society of America
  • 国際学会
• [学会発表] East Antarctic meltwater influx from the Wilkes Subglacial Basin since the Last Glacial Maximum as determined by beryllium isotope ratios (2021)
  • 著者名/発表者名: Bethany Behrens, Yosuke Miyairi, Adam D. Sproson, Masako Yamane, Yusuke Yokoyama
  • 学会等名: Japan Geoscience Union
• [学会発表] Holocene glacial dynamics of East Antarctica detected by beryllium isotope ratios from the Adelie Basin (2021)
  • 著者名/発表者名: Bethany Behrens, Yusuke Yokoyama, Yosuke Miyairi, Adam D. Sproson, Masako Yamane, Francisco J. Jimenez-Espejo
  • 学会等名: Geological Society of America
• [学会発表] East Antarctic meltwater influx from the Wilkes Subglacial Basin since the Last Glacial Maximum as determined by beryllium isotopes (2021)
  • 著者名/発表者名: Bethany Behrens, Yosuke Miyairi, Adam D. Sproson, Masako Yamane, Yusuke Yokoyama
  • 学会等名: Australia Earth Sciences Convention
  • 国際学会
• [学会発表] East Antarctic meltwater influx from the Wilkes Subglacial Basin since the Last Glacial Maximum as determined by beryllium isotopes (2020)
  • 著者名/発表者名: Bethany Behrens, Yosuke Miyairi, Adam D. Sproson, Masako Yamane, Yusuke Yokoyama
  • 学会等名: Japan Geoscience Union