scholarly journals Optimal locations for GPS measurements in North America and northern Europe for constraining Glacial Isostatic Adjustment

2010 ◽  
Author(s):  
Patrick Wu ◽  
Holger Steffen ◽  
Hansheng Wang
Keyword(s):  
North America ◽  
Northern Europe ◽  
Glacial Isostatic Adjustment ◽  
Gps Measurements ◽  
Isostatic Adjustment

Use of GRACE determined secular gravity rates for glacial isostatic adjustment studies in North-America

2008 ◽  
Vol 46 (3-5) ◽  
pp. 144-154 ◽  
Author(s):  
Wouter van der Wal ◽  
Patrick Wu ◽  
Michael G. Sideris ◽  
C.K. Shum
Keyword(s):  
North America ◽  
Glacial Isostatic Adjustment ◽  
Isostatic Adjustment

scholarly journals Absolute gravity calibration of GPS velocities and glacial isostatic adjustment in mid-continent North America

2011 ◽  
Vol 38 (24) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. Mazzotti ◽  
A. Lambert ◽  
J. Henton ◽  
T. S. James ◽  
N. Courtier
Keyword(s):  
North America ◽  
Absolute Gravity ◽  
Glacial Isostatic Adjustment ◽  
Isostatic Adjustment ◽  
Gps Velocities

Glacial isostatic adjustment along the Pacific coast of central North America

2018 ◽  
Vol 193 ◽  
pp. 288-311 ◽  
Author(s):  
Maryam Yousefi ◽  
Glenn A. Milne ◽  
Ryan Love ◽  
Lev Tarasov
Keyword(s):  
North America ◽  
Pacific Coast ◽  
Glacial Isostatic Adjustment ◽  
Isostatic Adjustment ◽  
The Pacific

scholarly journals Uncertainties of Glacial Isostatic Adjustment Model Predictions in North America Associated With 3D Structure

2020 ◽  
Vol 47 (10) ◽  
Author(s):  
Tanghua Li ◽  
Patrick Wu ◽  
Hansheng Wang ◽  
Holger Steffen ◽  
Nicole S. Khan ◽  
...  
Keyword(s):  
North America ◽  
3D Structure ◽  
Glacial Isostatic Adjustment ◽  
Isostatic Adjustment ◽  
Adjustment Model ◽  
Model Predictions

Glacial Isostatic Adjustment with 3D Earth models: A comparison of case studies of deglacial relative sea level records of North America and Russian Arctic

2020 ◽  
Author(s):  
Tanghua Li ◽  
Nicole Khan ◽  
Simon Engelhart ◽  
Alisa Baranskaya ◽  
Peltier William ◽  
...  
Keyword(s):  
North America ◽  
Sea Level ◽  
3D Models ◽  
Viscosity Model ◽  
Glacial Isostatic Adjustment ◽  
Russian Arctic ◽  
Scaling Factors ◽  
Relative Sea Level ◽  
Isostatic Adjustment ◽  
Best Fit

<p>The Canadian landmass of North America and the Russian Arctic were covered by large ice sheets during the Last Glacial Maximum, and have been key areas for Glacial Isostatic Adjustment (GIA) studies. Previous GIA studies have applied 1D models of Earth’s interior viscoelastic structure; however, seismic tomography, field geology and recent studies reveal the potential importance of 3D models of this structure. Here, using the latest quality-controlled deglacial sea-level databases from North America and the Russian Arctic, we investigate the effects of 3D structure on GIA predictions. We explore scaling factors in the upper mantle (<em>β<sub>UM</sub></em>) and lower mantle (<em>β<sub>LM</sub></em>) and the 1D background viscosity model (<em>η<sub>o</sub></em>) with predictions of of the ICE-6G_C (VM5a) glaciation/deglaciation model of Peltier et al (2015, JGR) in these two regions, and compare with the best fit 3D viscosity structures.</p><p>We compute gravitationally self-consistent relative sea-level histories with time dependent coastlines and rotational feedback using both the Normal Mode Method and Coupled Laplace-Finite Element Method. A subset of 3D GIA models is found that can fit the deglacial sea-level databases for both regions. These databases cover both the near and intermediate field regions. However, North America and Russian Arctic prefer different 3D structures (i.e., combinations of (<em>η<sub>o</sub>, β<sub>UM</sub>, β<sub>LM</sub></em>)) to provide the best fits. The Russian Arctic database prefers a softer background viscosity model (<em>η<sub>o</sub></em>), but larger scaling factors (<em>β<sub>UM</sub>, β<sub>LM</sub></em>) than those preferred by the North America database.</p><p>Outstanding issues include the uncertainty of the history of local glaciation history. For example, preliminary modifications of the ice model in Russian Arctic reveal that the misfits of 1D models can be significantly reduced, but still fit less well than the best fit 3D GIA model.An additional issue concerns the extent to which the 3D models are able to improve both fits in North America and Russian Arctic when compared with 1D internal structure (ICE-6G_C VM5a & ICE-7G VM7), will be assessed in a preliminary fashion.</p>

scholarly journals The glacial isostatic adjustment signal at present day in northern Europe and the British Isles estimated from geodetic observations and geophysical models

Solid Earth ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 777-795 ◽  
Author(s):  
Karen M. Simon ◽  
Riccardo E. M. Riva ◽  
Marcel Kleinherenbrink ◽  
Thomas Frederikse
Keyword(s):  
Mass Loss ◽  
Barents Sea ◽  
Joint Inversion ◽  
Vertical Motion ◽  
Ice Age ◽  
Northern Europe ◽  
Glacial Isostatic Adjustment ◽  
British Isles ◽  
Isostatic Adjustment ◽  
Vertical Land Motion

Abstract. The glacial isostatic adjustment (GIA) signal at present day is constrained via the joint inversion of geodetic observations and GIA models for a region encompassing northern Europe, the British Isles, and the Barents Sea. The constraining data are Global Positioning System (GPS) vertical crustal velocities and GRACE (Gravity Recovery and Climate Experiment) gravity data. When the data are inverted with a set of GIA models, the best-fit model for the vertical motion signal has a χ2 value of approximately 1 and a maximum a posteriori uncertainty of 0.3–0.4 mm yr−1. An elastic correction is applied to the vertical land motion rates that accounts for present-day changes to terrestrial hydrology as well as recent mass changes of ice sheets and glaciered regions. Throughout the study area, mass losses from Greenland dominate the elastic vertical signal and combine to give an elastic correction of up to +0.5 mm yr−1 in central Scandinavia. Neglecting to use an elastic correction may thus introduce a small but persistent bias in model predictions of GIA vertical motion even in central Scandinavia where vertical motion is dominated by GIA due to past glaciations. The predicted gravity signal is generally less well-constrained than the vertical signal, in part due to uncertainties associated with the correction for contemporary ice mass loss in Svalbard and the Russian Arctic. The GRACE-derived gravity trend is corrected for present-day ice mass loss using estimates derived from the ICESat and CryoSat missions, although a difference in magnitude between GRACE-inferred and altimetry-inferred regional mass loss rates suggests the possibility of a non-negligible GIA response here either from millennial-scale or Little Ice Age GIA.

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