Inversion of three-dimensional features of Antarctic subglacial lakes --- A case study in Lake Vostok
at : Dec 18, 2018 09:55:05  (view:1238)

Authors: Yan li1,2, Yang Lu1,2, Zizhan Zhang1,2, Hongling Shi1,2, Hui Xi1,2

 

1 State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 430077 Wuhan, China;

2 University of Chinese Academy of Sciences, 100049 Beijing, China

Corresponding author: Zizhan Zhang, zzhang@asch.whigg.ac.cn

Abstract: Three-dimensional features of subglacial lakes are critical to estimating basal water storage beneath Antarctic ice sheet. To quantify subglacial water storage, we present a method to implement inversion of three-dimensional features of Antarctic subglacial lakes according to hydraulic potential theory. In the experiment, Lake Vostok is chosen as an example because comprehensive and multi kinds of measurements were obtained over and around the lake. According to the estimate, Lake Vostok covers about 13,300 km2 beneath ice sheet. It consists of two sub-basins separated by a ridge with about 200-300 m water depths. The coverage of the smaller northern sub-basin is about half of the coverage of the southern basin. Corresponding deepest depths of northern and southern sub-basins are about 450 m and 850 m, respectively. Volume of total water is about 4700 km3. These estimates are compared with previous results by seismic reflections and aerogravity inversion. In general, our derived estimates are closer to results by aerogravity inversion than that by seismic reflections. The validation indicates the feasibility of using our method to estimate water depths of other subglacial lakes.

Keywords:  three-dimensional features; Lake Vostok; hydraulic potential; subglacial water storage