Relationship between glacial isostatic adjustment and gravity perturbations observed by GRACE

• Published in: Geophysical Research Letters
• Main Authors: Purcell, Anthony, Dehecq, Amaury, Tregoning, Paul, Potter, Emma-Kate, Mcclusky, Simon, Lambeck, Kurt
• Other Authors: Research School of Earth Sciences Canberra (RSES), Australian National University (ANU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: GRACE; glacio-isostatic adjustment; uplift estimates; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; [SDE.MCG]Environmental Sciences/Global Changes; Antarc*; Antarctica
• Online Access: https://hal.archives-ouvertes.fr/hal-00967316; https://hal.archives-ouvertes.fr/hal-00967316/document; https://hal.archives-ouvertes.fr/hal-00967316/file/Purcell_et_al._-_2011_-_Relationship_between_glacial_isostatic_adjustment_.pdf; https://doi.org/10.1029/2011GL048624

International audience The Gravity Recovery and Climate Experiment space gravity mission provides one of the principal means of estimating present-day mass loss occurring in polar regions. Extraction of the mass loss signal from the observed gravity changes is complicated by the need to first remove the signal of ongoing glacial isostatic adjustment (GIA) since the Last Glacial Maximum. This can be problematic in regions such as Antarctica where the GIA models are poorly constrained by observation and their accuracy is not well known. We present a new methodology that permits the GIA component to be represented mathematically by a simple, linear expression of the ratio of viscoelastic Love numbers that is valid for a broad range of Earth and ice-load models. The expression is shown to reproduce rigorous computations of surface uplift rates to within 0.3 mm/yr, thus providing a means of inverting simultaneously for present-day mass loss and ongoing GIA with all the accuracy of a fully detailed forward model.