Vertical and horizontal surface displacements near Jakobshavn Isbræ driven by melt‐induced and dynamic ice loss

We analyze Global Positioning System (GPS) time series of relative vertical and horizontal surface displacements from 2006 to 2012 at four GPS sites located between ∼5 and ∼150 km from the front of Jakobshavn Isbræ (JI) in west Greenland. Horizontal displacements during 2006–2010 at KAGA, ILUL, and QEQE, relative to the site AASI, are directed toward north‐west, suggesting that the main mass loss signal is located near the frontal portion of JI. The directions of the observed displacements are supported by modeled displacements, derived from NASA's Airborne Topographic Mapper (ATM) surveys of surface elevations from 2006, 2009, and 2010. However, horizontal displacements during 2010–2012 at KAGA and ILUL are directed more towards the west suggesting a change in the spatial distribution of the ice mass loss. In addition, we observe an increase in the uplift rate during 2010–2012 as compared to 2006–2010. The sudden change in vertical and horizontal displacements is due to enhanced melt‐induced ice loss in 2010 and 2012.

[1]  M. Bevis,et al.  Crustal uplift due to ice mass variability on Upernavik Isstrøm, west Greenland , 2012 .

[2]  Jian Wang,et al.  Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate change , 2012, Proceedings of the National Academy of Sciences.

[3]  G. Spada,et al.  Greenland uplift and regional sea level changes from ICESat observations and GIA modelling , 2012 .

[4]  S. Swenson,et al.  Recent contributions of glaciers and ice caps to sea level rise , 2012, Nature.

[5]  Xavier Collilieux,et al.  ITRF2008 plate motion model , 2011 .

[6]  Ian M. Howat,et al.  Mass balance of Greenland's three largest outlet glaciers, 2000–2010 , 2011 .

[7]  Riccardo E. M. Riva,et al.  A benchmark study for glacial isostatic adjustment codes , 2011 .

[8]  Sebastian B. Simonsen,et al.  Mass balance of the Greenland ice sheet (2003–2008) from ICESat data – the impact of interpolation, sampling and firn density , 2011 .

[9]  G. Milne,et al.  The influence of decadal‐ to millennial‐scale ice mass changes on present‐day vertical land motion in Greenland: Implications for the interpretation of GPS observations , 2011 .

[10]  Ian M. Howat,et al.  GPS measurements of crustal uplift near Jakobshavn Isbræ due to glacial ice mass loss , 2010 .

[11]  Peter Steigenberger,et al.  Improved Constraints on Models of Glacial Isostatic Adjustment: A Review of the Contribution of Ground-Based Geodetic Observations , 2010 .

[12]  M. R. van den Broeke,et al.  Partitioning Recent Greenland Mass Loss , 2009, Science.

[13]  I. Velicogna.  Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE , 2009 .

[14]  G. Milne,et al.  Calibrating a glaciological model of the Greenland ice sheet from the Last Glacial Maximum to present-day using field observations of relative sea level and ice extent , 2009 .

[15]  A. Dziewoński,et al.  Anisotropic shear‐wave velocity structure of the Earth's mantle: A global model , 2008 .

[16]  J. Kouba.  Implementation and testing of the gridded Vienna Mapping Function 1 (VMF1) , 2008 .

[17]  Shfaqat Abbas Khan,et al.  Geodetic measurements of postglacial adjustments in Greenland , 2008 .

[18]  J. Wahr,et al.  Elastic uplift in southeast Greenland due to rapid ice mass loss , 2007 .

[19]  Giorgio Spada,et al.  SELEN: A Fortran 90 program for solving the "sea-level equation" , 2007, Comput. Geosci..

[20]  H. Schuh,et al.  Troposphere mapping functions for GPS and very long baseline interferometry from European Centre for Medium‐Range Weather Forecasts operational analysis data , 2006 .

[21]  R. Dietrich,et al.  Present-day vertical crustal deformations in West Greenland from repeated GPS observations , 2005 .

[22]  K. Lambeck,et al.  Constraints on the Greenland Ice Sheet since the Last Glacial Maximum from sea-level observations and glacial-rebound models , 2004 .

[23]  W. Peltier.  GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE , 2004 .

[24]  J. Zumberge,et al.  Precise point positioning for the efficient and robust analysis of GPS data from large networks , 1997 .

[25]  D. L. Anderson,et al.  Preliminary reference earth model , 1981 .

[26]  W. Farrell.  Deformation of the Earth by surface loads , 1972 .

[27]  Xavier Fettweis,et al.  The role of albedo and accumulation in the 2010 melting record in Greenland , 2011 .

[28]  P. Novák.  High Resolution Constituents of the Earth’s Gravitational Field , 2009 .

[29]  Hans-Georg Scherneck,et al.  Ocean Tide and Atmospheric Loading , 2002 .

[30]  C. Bassin,et al.  The Current Limits of resolution for surface wave tomography in North America , 2000 .