2020 Fiscal Year Annual Research Report
| Project/Area Number |
20J21145
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| Research Institution | The University of Tokyo |
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Principal Investigator |
BEHRENS BETHANY 東京大学, 総合文化研究科, 特別研究員(DC1)
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| Project Period (FY) |
2020-04-24 – 2023-03-31
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| Keywords | East Antarctica / Holocene / beryllium / cosmogenic isotopes / glacial discharge / glacial cycles |
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| Outline of Annual Research Achievements |
Additional analysis of Adelie Basin, East Antarctica, samples using the leaching method for beryllium-10 (10Be) and beryllium-9 (9Be) was carried out to obtain a ratio curve representative of glacial discharge. The core we are analyzing is 185 meters long and covers the Holocene epoch. This research was presented at the Australia Earth Sciences Convention in February, and we are currently writing a manuscript outlining the 10Be/9Be results.
Analysis has begun on 10Be/9Be ratio of samples from Lake Selina, Tasmania. Based on the 10Be/9Be results, it is possible to identify the Laschamp geomagnetic excursion, and with further analysis we expect to see the Blake geomagnetic excursion, as well. We have also begun pretreatment for grain size analysis to examine changes in wind regime.
Grain size analysis for four cores from the Sabrina Coast, East Antarctica has been completed. The longer piston cores results show a cyclicity similar to the magnetic susceptibility logs, and the periods with larger grain size in the kasten cores seem to correspond with ice sheet retreat. We will know with more certainty after the age model is complete. Analysis for 10Be/9Be has begun for two of these cores with which we plan to assess glacial advance and retreat over the past few glacial-interglacial cycles.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
The lockdown during spring 2020 due to the pandemic delayed the 10Be/9Be preparation and analysis by a couple of months. Therefore, the manuscript we are writing to present these results was also delayed. However, we were able to make good progress with grain size analysis, finishing all cores from the Sabrina Coast.
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| Strategy for Future Research Activity |
Adelie Basin, East Antarctica, 10Be/9Be ratio analysis will be completed this year for a high-resolution analysis of Holocene glacial dynamics of the Wilkes Basin. The compound specific 14C dating will be carried out for the cores from the Sabrina Coast, East Antarctica, as will additional 10Be/9Be analysis. We will continue analysis of Lake Selina 10Be/9Be to explore paleogeomagnetic excursions.
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