Postglacial induced surface motions, sea-levels and geoid rates on a spherical, self-gravitating laterally heterogeneous earth

Wu, Patrick; Wang, Hansheng; Schotman, H. H. A.

doi:10.1016/j.jog.2004.08.006

Cited by 45 publications

(46 citation statements)

References 24 publications

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“…This indicates lateral inhomogeneities in the viscosity stratification (e.g. SABADINI, 2002; WU and VAN DER WAL, 2003;WU et al, 2005) or variations in the lithospheric thickness, e.g. the change between continental and oceanic lithospheres (e.g.…”

Section: Input Modelsmentioning

confidence: 99%

An Estimate of Global Mean Sea-level Rise Inferred from Tide-gauge Measurements Using Glacial-isostatic Models Consistent with the Relative Sea-level Record

Hagedoorn

Wolf

Martinec

2007

Pure appl. geophys.

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This study is concerned with the influence of the glacial-isostatic adjustment caused by the last Pleistocene deglaciation on the present-day sea level. The viscoelastic deformation caused by the time-variable ice and ocean loads is simulated by computing the resulting perturbations for a spherical, self-gravitating, incompressible, Maxwell-viscoelastic earth model. The associated variation of the earth rotation is described in terms of the Liouville equation, which is solved by means of the MacCullagh formulae. This allows the determination of the vertical displacement and geoid height and, thus, the solution of the sea-level equation. We test several viscosity and ice models and evaluate them by comparison of the computed response with the Holocene relative sea-level record. Using the optimum combination of viscosity and ice models, we then estimate the influence of the last Pleistocene deglaciation on the tide-gauge measurements. A comparison between the observational and residual linear trends for the tide-gauge measurements shows a significant reduction of the variance and geographical variability for the latter, in particular for the formerly ice-covered regions of North America and Scandinavia. The favoured value determined for the global mean sea-level rise is (1.46±0.2) mm a )1 .

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Section: Input Modelsmentioning

confidence: 99%

An Estimate of Global Mean Sea-level Rise Inferred from Tide-gauge Measurements Using Glacial-isostatic Models Consistent with the Relative Sea-level Record

Hagedoorn

Wolf

Martinec

2007

Pure appl. geophys.

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“…Consider, for example, the possible inclusion of lateral variations in mantle viscosity. State-of-the-art GIA predictions that permit 3-D variations in viscosity suggest that the effect on sea-level predictions will be on the order of a few mm/yr (e.g., Paulson et al, 2005;Wu et al, 2005;Kendall et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Post-Glacial Isostatic Adjustment and Global Warming in Subarctic Canada: Implications for Islands of the James Bay Region

Tsuji¹,

Gomez²,

Mitrovica³

et al. 2009

ARCTIC

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ABSTRACT. When Rupert's Land and the North-Western Territory became a part of Canada as the Northwest Territories in 1870, the islands of James Bay were included within the new territorial boundaries. These same islands became a part of Nunavut in 1999, when the new territory was created from the eastern region of the Northwest Territories. Although the James Bay islands remain part of Nunavut, the western James Bay Cree assert that the western James Bay islands, including Akimiski Island, were part of the Cree traditional territory and that these islands have never been surrendered through treaty. This land-claim issue is further complicated by the fact that glacial isostatic adjustment (GIA) is occurring in the James Bay region and that the islands of James Bay may one day become part of mainland Ontario or Quebec. We used numerical models of the GIA process to predict how shorelines in James Bay will migrate over the next 1000 years as a result of post-glacial sea-level changes. These predictions, which were augmented by an additional contribution associated with sea-level rise due to global warming, were used to determine whether the islands in James Bay will ever become part of the mainland. The predictions for the islands are sensitive to the two primary inputs into the GIA predictions, namely the models for the geometry of the ancient Laurentide ice sheet and the viscoelastic structure adopted for the solid earth, as well as to the amplitude of the projected global warming signal. Nevertheless, it was found that many of the smaller and larger islands of James Bay will likely join the mainland of either Ontario or Quebec. For example, using a global warming scenario of 1.8 mm sea-level rise per year, a plausible range of GIA models suggests that the Strutton Islands and Cape Hope Islands will join mainland Quebec in ~400 years or more, while Akimiski Island will take at least ~700 years to join mainland Ontario. Using the same GIA models, but incorporating the upper boundary of global warming scenarios of 5.9 mm sea-level rise per year, the Strutton Islands and Cape Hope Islands are predicted to join mainland Quebec in ~600 years or more, and Akimiski Island is predicted not to join mainland Ontario. Since Akimiski Island is already being prospected for diamonds and the future ownership of emergent land remains an issue, these findings have great economic importance. Key words: sea-level change, subarctic Canada, post-glacial isostatic adjustment, global warming, islands of James Bay RÉSUMÉ. Quand la Terre de Rupert et le Territoire du Nord-Ouest ont joint les rangs du Canada sous le nom de Territoires du Nord-Ouest en 1870, les îles de la baie James ont été intégrées aux nouvelles frontières territoriales. Ces mêmes îles font maintenant partie du Nunavut depuis 1999, lorsque le nouveau territoire a été créé à partir de la région est des Territoires du Nord-Ouest. Bien que les îles de la baie James fassent toujours partie du Nunavut, les Cris de l'ouest de la baie James soutiennent que les îles du côté oue...

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“…However, other rheologies such as composite rheology (van der Wal et al, 2013) or models with laterally varying lithospheric thickness and/or mantle viscosities (Wu et al, 2005;Steffen et al, 2006;Wang et al, 2008;van der Wal et al, 2013;Wu et al, 2013) can also fit the observations in Fennoscandia reasonably well.…”

Section: H Steffen Et Al: Lithosphere and Upper-mantle Structure Ofmentioning

confidence: 98%

Lithosphere and upper-mantle structure of the southern Baltic Sea estimated from modelling relative sea-level data with glacial isostatic adjustment

2014

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Abstract. During the last glacial maximum, a large ice sheet covered Scandinavia, which depressed the earth's surface by several 100 m. In northern central Europe, mass redistribution in the upper mantle led to the development of a peripheral bulge. It has been subsiding since the begin of deglaciation due to the viscoelastic behaviour of the mantle. We analyse relative sea-level (RSL) data of southern Sweden, Denmark, Germany, Poland and Lithuania to determine the lithospheric thickness and radial mantle viscosity structure for distinct regional RSL subsets. We load a 1-D Maxwell-viscoelastic earth model with a global ice-load history model of the last glaciation. We test two commonly used ice histories, RSES from the Australian National University and ICE-5G from the University of Toronto.Our results indicate that the lithospheric thickness varies, depending on the ice model used, between 60 and 160 km. The lowest values are found in the Oslo Graben area and the western German Baltic Sea coast. In between, thickness increases by at least 30 km tracing the Ringkøbing-Fyn High. In Poland and Lithuania, lithospheric thickness reaches up to 160 km. However, the latter values are not well constrained as the confidence regions are large. Upper-mantle viscosity is found to bracket [2-7] × 10 20 Pa s when using ICE-5G. Employing RSES much higher values of 2 × 10 21 Pa s are obtained for the southern Baltic Sea. Further investigations should evaluate whether this ice-model version and/or the RSL data need revision. We confirm that the lower-mantle viscosity in Fennoscandia can only be poorly resolved.The lithospheric structure inferred from RSES partly supports structural features of regional and global lithosphere models based on thermal or seismological data. While there is agreement in eastern Europe and southwest Sweden, the structure in an area from south of Norway to northern Germany shows large discrepancies for two of the tested lithosphere models. The lithospheric thickness as determined with ICE-5G does not agree with the lithosphere models. Hence, more investigations have to be undertaken to sufficiently determine structures such as the Ringkøbing-Fyn High as seen with seismics with the help of glacial isostatic adjustment modelling.

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Postglacial induced surface motions, sea-levels and geoid rates on a spherical, self-gravitating laterally heterogeneous earth

Cited by 45 publications

References 24 publications

An Estimate of Global Mean Sea-level Rise Inferred from Tide-gauge Measurements Using Glacial-isostatic Models Consistent with the Relative Sea-level Record

An Estimate of Global Mean Sea-level Rise Inferred from Tide-gauge Measurements Using Glacial-isostatic Models Consistent with the Relative Sea-level Record

Post-Glacial Isostatic Adjustment and Global Warming in Subarctic Canada: Implications for Islands of the James Bay Region

Lithosphere and upper-mantle structure of the southern Baltic Sea estimated from modelling relative sea-level data with glacial isostatic adjustment

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