A Reanalysis and Reinterpretation of Geodetic and Geological Evidence of Glacial-Isostatic Adjustment in the Churchill Region, Hudson Bay

Wolf, Detlef; Klemann, Volker; Wünsch, J.; Zhang, Feipeng

doi:10.1007/s10712-005-0641-x

Cited by 48 publications

(41 citation statements)

References 81 publications

(109 reference statements)

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“…The uncertainty associated with the filtering and inversion procedure for the entire GrIS was estimated to be 75 mm equivalent water height for the monthly solutions and about 77% for the linear trends (Appendix A2). Following Paulson et al (2007), the GIA correction is a version of ICE-5G (Peltier, 2004), adjusted to reconcile with the GRACE estimates, assuming upper-and lower-mantle viscosities of 6 Â 10 20 Pa s and 2 Â 10 22 Pa s (Wolf et al, 2004), and an elastic lithosphere with a thickness of 100 km. The uncertainty of the GIA corrections is assessed with the alternative retreat history of Lambeck and Chappell (2001), and by varying upper-and lowermantle viscosities between 2 Â 10 20 and 8 Â 10 20 Pa s and between 5 Â 10 21 and 4 Â 10 22 Pa s, respectively, and the thickness of the lithosphere by 720 km.…”

Section: Gracementioning

confidence: 99%

Timing and origin of recent regional ice-mass loss in Greenland

Sasgen

Broeke

Bamber

et al. 2012

Earth and Planetary Science Letters

207

228

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Section: Gracementioning

confidence: 99%

Timing and origin of recent regional ice-mass loss in Greenland

Sasgen

Broeke

Bamber

et al. 2012

Earth and Planetary Science Letters

207

228

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“…In North America several hundreds of continuous GPS stations have been used to compute contemporary velocities (e.g., Calais et al, 2006;Wolf et al, 2006;Sella et al, 2007). In Greenland a campaign with repeated GPS has been carried out over a period of close to 10 years (Dietrich et al, 2005) with uplift values of the order mm/year close to the ice cap.…”

Section: Geodetic Observationsmentioning

confidence: 99%

“…An example of this is the study by Wolf et al (2006), who reviewed and analysed the geological, tide-gauge, GPS and gravimetric evidence of GIA in the Churchill region of Hudson Bay, Canada. As a result, they were able to show that the different types of observable are consistent and lead to values of about 3.2 × 10 20 Pa s and 1.6 × 10 22 Pa s for the upper-and lower-mantle viscosities, respectively.…”

Section: Current Models and Problems To Be Solvedmentioning

confidence: 99%

DynaQlim – Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas

Poutanen

Dransch

Gregersen

et al. 2009

New Frontiers in Integrated Solid Earth Sciences

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The isostatic adjustment of the solid Earth to the glacial loading (GIA, Glacial Isostatic Adjustment) with its temporal signature offers a great opportunity to retrieve information of Earth's upper mantle to the changing mass of glaciers and ice sheets, which in turn is driven by variations in Quaternary climate. DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) has its focus to study the relations between upper mantle dynamics, its composition and physical properties, temperature, rheology, and Quaternary climate. Its regional focus lies on the cratonic areas of northern Canada and Scandinavia.Geodetic methods like repeated precise levelling, tide gauges, high-resolution observations of recent movements, gravity change and monitoring of postglacial faults have given information on the GIA process for more than 100 years. They are accompanied by more recent techniques like GPS observations and the GRACE and GOCE satellite missions which provide additional global and regional constraints on the gravity field. Combining geodetic observations with seismological investigations, studies of the postglacial faults and continuum mechanical modelling of GIA, DynaQlim offers new insights into properties of the lithosphere. Another step toward a better understanding of GIA has been the joint inversion of different types of observational data -preferentially connected with geological relative sea-level evidence of the Earth's rebound during the last 10,000 years.Due to the changes in the lithospheric stress state large faults ruptured violently at the end of the last M. Poutanen ( ) Finnish Geodetic Institute, Geodeetinrinne 2, 02430 Masala, Finland e-mail: markku.poutanen@fgi.fi glaciation in large earthquakes, up to the magnitudes M W = 7-8. Whether the rebound stress is still able to trigger a significant fraction of intraplate seismic events in these regions is not completely understood due to the complexity and spatial heterogeneity of the regional stress field. Understanding of this mechanism is of societal importance.Glacial ice sheet dynamics are constrained by the coupled process of the deformation of the viscoelastic solid Earth, the ocean and climate variability. Exactly how the climate and oceans reorganize to sustain growth of ice sheets that ground to continents and shallow continental shelves is poorly understood. Incorporation of nonlinear feedback in modelling both ocean heat transport systems and atmospheric CO 2 is a major challenge. Climate-related loading cycles and episodes are expected to be important, hence also more shortterm features of palaeoclimate should be explicitly treated.

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“…These constraints, parameterized into the so-called decay time of uplift Forte, 1997, 2004;Peltier, 1998), suggest that a lower-mantle viscosity of more than 5 × 10 21 Pa s is unlikely, at least for the mantle region below Hudson Bay. (However, for a contrary view, see Wolf et al, 2006.) Therefore, in the predictions presented below, we limit our attention to results for four values of lower-mantle viscosity: 1 × 10 21 Pa s, 2 × 10 21 Pa s, 3 × 10 21 Pa s, and 5 × 10 21 Pa s. The ICE-5G ice history is most appropriately paired with a specific viscosity model VM2 (Peltier, 2004).…”

Section: Sea-level Change -Glacial Isostatic Adjustment (Gia)mentioning

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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A Reanalysis and Reinterpretation of Geodetic and Geological Evidence of Glacial-Isostatic Adjustment in the Churchill Region, Hudson Bay

Cited by 48 publications

References 81 publications

Timing and origin of recent regional ice-mass loss in Greenland

Timing and origin of recent regional ice-mass loss in Greenland

DynaQlim – Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas

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

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