Distribution of Bouguer gravity anomaly and crust and upper mantle in the Antarctic region

• Main Authors: Takeshi Matsumoto, Jiro Segawa, Katsutada Kaminuma
• Format: Article in Journal/Newspaper
• Language: English; Japanese
• Published: National Institute of Polar Research 1986
• Subjects: Geography (General); G1-922; Antarctic; The Antarctic; Ross Sea; Antarc*; Ice Sheet
• Online Access: https://doi.org/10.15094/00008517; https://doaj.org/article/7dff731a7596401cbe0368837741ef7c

Bouguer gravity anomaly south of 45°S was derived from the newly provided data of free-air anomaly and topography, and its implications in the crust and upper mantle structure of the land and its marginal ocean area were discussed from the viewpoint of gravity anomaly. Bouguer anomaly in the Antarctic Continent presents negative anomaly, showing that the land area is in isostatic equilibrium with the thick crust supporting the load of both thick ice sheet and bedrock topography. In the surrounding ocean area exists the zone of relatively negative anomaly corresponding to the mid-oceanic ridges. The result of further analysis shows that there is some relationship between the sub-bottom structure of the Ross Sea and that of mid-oceanic ridges, and that no clear boundary of lithosphere and asthenosphere is recognized, which suggests that the asthenosphere reaches up to the bottom of the crust in this place.