| Titre | A new glacial isostatic adjustment model for the Central and Northern Laurentide Ice Sheet based on relative sea-level and GPS measurements |
| Auteur | Simon, K M; James, T S; Henton, J A; Dyke, A S |
| Source | Geophysical Journal International no. 205, 2016 p. 1619-1636, https://doi.org/10.1093/gji/ggw103 |
| Année | 2016 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20150224 |
| Éditeur | Oxford University Press |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1093/gji/ggw103 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Canada; Colombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon;
Nunavut |
| SNRC | 1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560 |
| Sujets | retrait de la glace; épaisseurs des glaces; écoulement glaciaire; directions des mouvements de la glace; glaciation; glaciers; glaciologie; épaisseurs des glaces; changements du niveau de la mer;
variations du niveau de la mer; niveaux paléomers; paléoclimatologie; paléoenvironnement; paléoclimats; paléotempératures; paléohydrologie; Calotte glaciaire Laurentide; géologie générale; sédimentologie; géologie des dépôts
meubles/géomorphologie |
| Illustrations | maps; location maps; icesheet maps; equations; graphs; charts; structural maps |
| |
| Programme | Infrastructure côtière, Géosciences de changements climatiques |
| Résumé | (disponible en anglais seulement)
The thickness and equivalent global sea-level contribution of an improved model of the central and northern Laurentide Ice Sheet is constrained by 24 relative
sea-level histories and 18 present-day GPS-measured vertical land motion rates. The final model, termed Laur15, is derived from the ICE-5G model by iteratively adjusting the thickness history in four regions of northern Canada. In the final model,
the last glacial maximum (LGM) thickness of the Laurentide Ice Sheet west of Hudson Bay was ~3.4-3.6 km. Conversely, east of Hudson Bay, peak ice thicknesses reached ~4 km. The ice model thicknesses inferred for these two regions represent,
respectively, a ~30% decrease and an average ~20-25% increase to the load thickness relative to the ICE-5G reconstruction, a result which is generally consistent with other recent studies that have focussed on Laurentide Ice Sheet history. The final
model also features peak ice thicknesses of 1.2-1.3 km in the Baffin Island region, a modest reduction relative to ICE-5G, and unchanged thicknesses for a region in the central Canadian Arctic Archipelago west of Baffin Island. Vertical land motion
predictions of the final model fit observed crustal uplift rates well, after an adjustment is made for the elastic crustal response to present-day ice mass changes of regional ice cover. The new Laur15 model provides more than a factor of two
improvement of the fit to the RSL data (?2 measure of misfit) and a factor of nine improvement to the fit of the GPS data (mean squared error measure of fit), compared to the ICE-5G starting model. Laur15 also fits the regional RSL data better by a
factor of two and gives a similar fit to GPS uplift rates when compared to the recent ICE-6G model. The volume history of the Laur15 reconstruction corresponds to an up to 8 m reduction in global sea-level equivalent compared to ICE-5G. |
| Résumé | (Résumé en langage clair et simple, non publié)
Ceci est un article technique qui décrit une nouvelle reconstruction de la calotte glaciaire Laurentide du dernier maximum glaciaire (il ya
environ 21.000 ans) à sa disparition il ya environ 8000 ans . La calotte glaciaire Laurentide couvert une grande partie du Canada au cours de la dernière ère glaciaire . Le nouveau modèle intègre des mesures de variations du niveau de la mer et les
dernières actuelle mouvement vertical de la croûte mieux qu'un modèle précédent appelé ICE- 5G . Le modèle amélioré donne une meilleure compréhension du mouvement vertical de la terre et le changement du niveau de la mer à travers une grande partie
du nord du Canada et contribuera à donner des projections améliorées de l'évolution future du niveau de la mer . |
| GEOSCAN ID | 296937 |
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