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Yusuke YOKOYAMA

Low Latitude Climate Induced Antarctic Melting Revealed from Far-filed Sea Level Records and Near-filed Meteoric Cosmogenic Nuclides in Sediments

Abstract
Far-fields sea level records are useful to reconstruct polar ice sheets melting histories because they are relatively less sensitive to solid Earth properties (Yokoyama & Purcell, 2021). Since Antarctic ice sheets deglacial pathways are still not yet fully understood, mid- to late- Holocene far-filed sea levels can constraint the ice sheets behavior in the past with respect to global climate changes (eg., Yokoyama et al., 2019a). In the meantime, information obtained from near-field sites are useful to unveil the region of the ice discharges in the Antarctica (eg., Yokoyama et al., 2016). High precision mass spectrometry (eg., Sproson et al., 2021; Yokoyama et al., 2019b) allows us to disintegrate the sediments sources either from bedrock, ice, marine etc. In this presentation, we demonstrate the evidence of Holocene melting of Antarctica using combined methods between far-field sea levels and near-filed meltwater signatures using cosmogenic nuclides. They suggested the close relations between low latitude climate and Antarctic melting. In particular, mechanisms of ocean-driven melting of ice shelves by upwelling of warm ocean water onto the continental shelf (Behrens et al, 2022) and atmospheric river induced surface melting of glaciers along the Antarctic coast were featured (Sproson et al., 2022). We will also discuss the importance of thorough exercises of data and model comparison that has been conducted by PALSEA to solve various issues including so-called missing ice problem. References:Behrens, B.C. et al., (2022) Quaternary Science Advances, 7, 100054.Sproson, A.D., et al. (2021) Rapid Comm. in Mass Spectrometry, e9059, 429, 106312.Sproson, A.D., et al. (2022) Nature CommunicationsYokoyama, Y. and Purcell, A. (2021) Geoscience Letters 8:13.Yokoyama, Y., et al. (2019a) Quaternary Science Reviews 206:150–161Yokoyama, Y., et al. (2019b) Nucl. Instr. Meth. In Phys. Res, B. 455, 260-264.Yokoyama, Y., et al. (2016) PNAS, 113, 2354.




Yusuke YOKOYAMA
The University of Tokyo, Japan

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