Thermohaline structure and circulation beneath the Langhovde Glacier ice shelf in East Antarctica

• Published in: Nature Communications
• Main Authors: Minowa, Masahiro, Sugiyama, Shin, Ito, Masato, Yamane, Shiori, Aoki, Shigeru
• Other Authors: MEXT | Japan Society for the Promotion of Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry; Antarctic; East Antarctica; Langhovde; Langhovde Glacier; Antarc*; Antarctica; Ice Shelf; Ice Shelves
• Online Access: http://dx.doi.org/10.1038/s41467-021-23534-w; http://www.nature.com/articles/s41467-021-23534-w.pdf; http://www.nature.com/articles/s41467-021-23534-w

Abstract Basal melting of ice shelves is considered to be the principal driver of recent ice mass loss in Antarctica. Nevertheless, in-situ oceanic data covering the extensive areas of a subshelf cavity are sparse. Here we show comprehensive structures of temperature, salinity and current measured in January 2018 through four boreholes drilled at a ~3-km-long ice shelf of Langhovde Glacier in East Antarctica. The measurements were performed in 302–12 m-thick ocean cavity beneath 234–412 m-thick ice shelf. The data indicate that Modified Warm Deep Water is transported into the grounding zone beneath a stratified buoyant plume. Water at the ice-ocean interface was warmer than the in-situ freezing point by 0.65–0.95°C, leading to a mean basal melt rate estimate of 1.42 m a −1 . Our measurements indicate the existence of a density-driven water circulation in the cavity beneath the ice shelf of Langhovde Glacier, similar to that proposed for warm-ocean cavities of larger Antarctic ice shelves.