scholarly journals The contribution of glacial isostatic adjustment to projections of sea‐level change along the Atlantic and Gulf coasts of North America

2016 ◽  
Vol 4 (10) ◽  
pp. 440-464 ◽  
Author(s):  
Ryan Love ◽  
Glenn A. Milne ◽  
Lev Tarasov ◽  
Simon E. Engelhart ◽  
Marc P. Hijma ◽  
...  
Keyword(s):  
North America ◽  
Sea Level ◽  
Sea Level Change ◽  
Glacial Isostatic Adjustment ◽  
Level Change ◽  
Isostatic Adjustment

3D glacial-isostatic adjustment models using geodynamically constrained Earth structures

2021 ◽  
Author(s):  
Meike Bagge ◽  
Volker Klemann ◽  
Bernhard Steinberger ◽  
Milena Latinović ◽  
Maik Thomas
Keyword(s):  
Solid Earth ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Change ◽  
Glacial Isostatic Adjustment ◽  
Level Change ◽  
Isostatic Adjustment ◽  
Mantle Viscosity ◽  
The Earth ◽  
Earth Structures

<p>The interaction between ice sheets and the solid Earth plays an important role for ice-sheet stability and sea-level change and hence for global climate models. Glacial-isostatic adjustment (GIA) models enable simulation of the solid Earth response due to variations in ice-sheet and ocean loading and prediction of the relative sea-level change. Because the viscoelastic response of the solid Earth depends on both ice-sheet distribution and the Earth’s rheology, independent constraints for the Earth structure in GIA models are beneficial. Seismic tomography models facilitate insights into the Earth’s interior, revealing lateral variability of the mantle viscosity that allows studying its relevance in GIA modeling. Especially, in regions of low mantle viscosity, the predicted surface deformations generated with such 3D GIA models differ considerably from those generated by traditional GIA models with radially symmetric structures. But also, the conversion from seismic velocity variations to viscosity is affected by a set of uncertainties. Here, we apply geodynamically constrained 3D Earth structures. We analyze the impact of conversion parameters (reduction factor in Arrhenius law and radial viscosity profile) on relative sea-level predictions. Furthermore, we focus on exemplary low-viscosity regions like the Cascadian subduction zone and southern Patagonia, which coincide with significant ice-mass changes.</p>

Quantifying the influence of glacial isostatic adjustment on current and future sea-level change using 3-D Earth models

2021 ◽  
Author(s):  
Glenn Milne ◽  
Maryam Yousefi ◽  
Konstantin Latychev
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
Glacial Isostatic Adjustment ◽  
Sea Level Changes ◽  
Model Parameter ◽  
Velocity Models ◽  
Level Change ◽  
Isostatic Adjustment ◽  
Vertical Land Motion ◽  
Earth Models

<p>Ongoing deformation of the Earth in response to past ice-ocean mass exchange is a significant contributor to contemporary sea-level changes and will be an important contributor to future changes. Calibrated models of this process, conventionally termed glacial isostatic adjustment (GIA), have been used to determine its influence on current and future sea-level changes. To date, the majority of these models have assumed a spherically-symmetric (1-D) representation of Earth structure. Here we apply a model that can simulate the isostatic response of a 3-D Earth in order to consider the contribution of lateral structure to model estimates of current and future sea-level change. We will present results from a global analysis based on two independent ice history reconstructions and a suite of 3-D Earth models with viscosity structure constrained using different seismic velocity models and recent estimates of lithosphere thickness variations. The accuracy of these GIA model parameter sets is assessed by comparing model output to a recently published data set of vertical land motion specifically intended to provide a robust measure of the GIA signal (Schumacher et al., Geophysical Journal International, 2018). This comparison indicates that the inclusion of lateral Earth viscosity structure results in an improved fit to the GPS-determined vertical land motion rates although significant residuals persist in some regions indicating that further efforts to improve constraints on this structure are necessary. Using the model parameter sets that best match the GPS constraints to predict the contribution of GIA to contemporary sea-level change indicates that lateral viscosity structure impacts the model estimates by order 1 mm/yr in some regions and that the model uncertainty is of a similar amplitude. Simulations of the GIA contribution to future sea-level change are also significantly affected, with differences, relative to a 1-D Earth model, reaching several decimetres on century timescales and several metres on millennial timescales. </p>

scholarly journals Refining Estimates of Polar Ice Volumes during the MIS11 Interglacial Using Sea Level Records from South Africa

2014 ◽  
Vol 27 (23) ◽  
pp. 8740-8746 ◽  
Author(s):  
Florence Chen ◽  
Sarah Friedman ◽  
Charles G. Gertler ◽  
James Looney ◽  
Nizhoni O’Connell ◽  
...  
Keyword(s):  
South Africa ◽  
Sea Level Rise ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Change ◽  
Polar Ice ◽  
Level Change ◽  
Isostatic Adjustment ◽  
West Antarctic ◽  
Numerical Predictions

Abstract Peak eustatic sea level (ESL), or minimum ice volume, during the protracted marine isotope stage 11 (MIS11) interglacial at ~420 ka remains a matter of contention. A recent study of high-stand markers of MIS11 age from the tectonically stable southern coast of South Africa estimated a peak ESL of 13 m. The present study refines this estimate by taking into account both the uncertainty in the correction for glacial isostatic adjustment (GIA) and the geographic variability of sea level change following polar ice sheet collapse. In regard to the latter, the authors demonstrate, using gravitationally self-consistent numerical predictions of postglacial sea level change, that rapid melting from any of the three major polar ice sheets (West Antarctic, Greenland, or East Antarctic) will lead to a local sea level rise in southern South Africa that is 15%–20% higher than the eustatic sea level rise associated with the ice sheet collapse. Taking this amplification and a range of possible GIA corrections into account and assuming that the tectonic correction applied in the earlier study is correct, the authors revise downward the estimate of peak ESL during MIS11 to 8–11.5 m.

scholarly journals Relative sea‐level change and postglacial isostatic adjustment along the coast of south Devon, United Kingdom

2008 ◽  
Vol 23 (5) ◽  
pp. 415-433 ◽  
Author(s):  
Anthony C. Massey ◽  
W. Roland Gehrels ◽  
Dan J. Charman ◽  
Glenn A. Milne ◽  
W. Richard Peltier ◽  
...  
Keyword(s):  
United Kingdom ◽  
Sea Level ◽  
Sea Level Change ◽  
Relative Sea Level ◽  
Level Change ◽  
Isostatic Adjustment
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