2023-06-23 スウォンジー大学
◆イギリス南極調査局（BAS）の研究チームによるこの研究は、地理学部の氷河学者であるベルント・クレッサ教授も関与し、新たな地質地図が科学誌に掲載された。この知見は、氷河の基底剪断応力に直接影響を与え、氷が海洋に流れ込む速度に関わる。今後はより詳細な研究が行われ、将来の氷の流失をより正確に予測するための基盤が提供されることが期待されている。
＜関連情報＞
- https://www.swansea.ac.uk/press-office/news-events/news/2023/06/ground-beneath-antarcticas-most-vulnerable-glacier-mapped-for-first-time.php
- https://www.science.org/doi/10.1126/sciadv.adf2639
統合された航空地球物理学的観測から得られた、西南極、スウェイツ氷河の地質スケッチマップと氷流への影響 Geological sketch map and implications for ice flow of Thwaites Glacier, West Antarctica, from integrated aerogeophysical observations
Tom A. Jordan,Sarah Thompson,Bernd Kulessa and Fausto Ferraccioli
Science Advances Published:31 May 2023
DOI:https://doi.org/10.1126/sciadv.adf2639
Abstract
The geology beneath Thwaites Glacier, the Antarctic glacial catchment most vulnerable to climate change, is unknown. Thwaites Glacier lies within the West Antarctic Rift System, but details of the subglacial geology relevant to glacial flow, including sediment availability, underlying lithology, and heat flux, are lacking. We present the first sketch map of the subglacial geology of Thwaites Glacier, interpreted from maps of airborne gravity, magnetic and radar data, supported by 2D models and 3D inversion of subsurface properties, and the regional geological context. A zone of Cretaceous mafic magmatism extending ~200 km inland from the coast is interpreted, while sedimentary basins are restricted to a region 150 to 200 km inboard of the coast, underlying just 20% of the catchment. Several granitic subglacial highlands are identified, forming long-lived topographic highs. Our geological interpretation places constraints on the basal properties of Thwaites Glacier, laying the foundation for both improved predictions of ice sheet change and studies of West Antarctic tectonics.
