Improved Constraints on Models of Glacial Isostatic Adjustment: A Review of the Contribution of Ground-Based Geodetic Observations

Matt A. King , Zuheir Altamimi , Johannes Boehm , Machiel Bos , Rolf Dach , Pedro Elosegui , François Fund (1) , Manuel Hernández-Pajares , David Lavallee , Paulo Jorge Mendes Cerveira , Nigel Penna , Riccardo E. M. Riva , Peter Steigenberger , Tonie van Dam , Luca Vittuari , Simon Williams , Pascal Willis (2)

1 LPGN - Laboratoire de Planétologie et Géodynamique de Nantes [UMR 6112]
2 IPGP - Institut de Physique du Globe de Paris

The provision of accurate models of Glacial Isostatic Adjustment (GIA) is presently a priority need in climate studies, largely due to the potential of the Gravity Recovery and Climate Experiment (GRACE) data to be used to determine accurate and continent-wide assessments of ice mass change and hydrology. However, modelled GIA is uncertain due to insufficient constraints on our knowledge of past glacial changes and to large simplifications in the underlying Earth models. Consequently, we show differences between models that exceed several mm/year in terms of surface displacement for the two major ice sheets: Greenland and Antarctica. Geodetic measurements of surface displacement offer the potential for new constraints to be made on GIA models, especially when they are used to improve structural features of the Earth’s interior as to allow for a more realistic reconstruction of the glaciation history. We present the distribution of presently available campaign and continuous geodetic measurements in Greenland and Antarctica and summarise surface velocities published to date, showing substantial disagreement between techniques and GIA models alike. We review the current state-of-the-art in ground-based geodesy (GPS, VLBI, DORIS, SLR) in determining accurate and precise surface velocities. In particular, we focus on known areas of need in GPS observation level models and the terrestrial reference frame in order to advance geodetic observation precision/accuracy toward 0.1 mm/year and therefore further constrain models of GIA and subsequent present-day ice mass change estimates.

Domaines: Planète et Univers [physics]

Matt A. King, Zuheir Altamimi, Johannes Boehm, Machiel Bos, Rolf Dach, et al.. Improved Constraints on Models of Glacial Isostatic Adjustment: A Review of the Contribution of Ground-Based Geodetic Observations. Surveys in Geophysics, 2010, 31 (5), pp.465-507. ⟨10.1007/s10712-010-9100-4⟩. ⟨insu-03605285⟩