Abstract:

The West Antarctic ice sheet has an important impact on global climate change and sea level rise and its dynamics and thermodynamics are among the focuses of polar research. Simulation of the ice sheet using numerical modeling constrains a study area’s dynamics and thermodynamics in the absence of observation data and it has become an important means of studying Antarctica. The Marie Byrd Land in West Amtarctica is near the Ford Mountain Range and the Ross Ice Shelf. In this paper, Elmer/Ice is used to simulate Marie Byrd Land’s western region’s ice velocity field, temperature field and pressure field. The study showed that the temperature field at the bottom of the ice sheet in this area was almost uniform, most of the ice bottom reached the pressure melting point, and only a small part of the ice bottom was still below the pressure melting point. There was no obvious difference in the bottom temperature fields among three simulations respectively using different geothermal fluxes (80 mW×m⁻², 100 mW×m⁻², 120 mW×m⁻²). The surface ice velocity was also simulated in the x, y, and z directions. The ice sheet’s simulated surface velocities were 0.012 – 744.7 m×a^–1. Model results indicate that the vertical direction has the greatest impact on the surface ice velocity; the stress field at the bottom of the ice sheet is roughly inversely proportional to the ice thickness. The z-direction profile from Bedmap 2 was used to analyze the causes of changes in ice flow velocities and ice sheet stress fields, and it is inferred that the existence of deep valleys under the ice may have a strong influence on the ice sheet velocity fields and stress fields.

Key words:

Antarctic ice sheet, Marie Byrd Land, Elmer/Ice, ice sheet temperature, ice velocity field, ice sheet pressure field