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TitreModeling 3-D crustal velocities in the United States and Canada
AuteurSnay, R A; Freymueller, J T; Craymer, M R; Pearson, C F; Saleh, J
SourceJournal of Geophysical Research, Solid Earth vol. 121, 2016 p. 5365-5388, https://doi.org/10.1002/2016JB012884 (Accès ouvert)
Année2016
Séries alt.Ressources naturelles Canada, Contribution externe 20170059
ÉditeurWiley-Blackwell
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1002/2016JB012884
Mediapapier; en ligne; numérique
Formatspdf
ProvinceCanada; 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
SNRC1; 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
Lat/Long OENS-160.0000 -60.0000 76.0000 30.0000
Lat/Long OENS-141.0000 -50.0000 90.0000 41.7500
Sujetssismo-sondages; vitesse des ondes sismiques; réseaux géodésiques; modèles de la croûte; études de la croûte; croûte continentale; relèvement isostatique; déglaciation; champs de glace; tectonique de plaques; géophysique; tectonique
Illustrationslocation maps; geological sketch maps; tables; formulae
Diffusé2016 07 15
Résumé(disponible en anglais seulement)
A numerical model for three-dimensional (3-D) crustal velocities has been derived for most of the United States and Canada, primarily from repeated geodetic data. This model provides a foundation for a prototype of the TRANS4D software. TRANS4D is being developed to enable geospatial professionals and others to transform 3-D positional coordinates across time. The derived model reveals several macroscopic features of the 3-D velocity field, including the pervasive presence of the glacial isostatic adjustment associated with the past melting of the ice fields that formed more than 19,000 years ago during the Last Glacial Maximum. In this study, the present-day 3-D velocity field associated with this melting (as estimated via the recently published ICE-6G C (VM5a) model) was subtracted from this study’s total 3-D velocity field to identify features of the residual velocity field. In particular, this study introduces the NA ICE-6G reference frame in which residual horizontal velocities have magnitudes that are less than 2 mm/yr everywhere east of longitude 104°W and south of latitude 60°N, except in southern Texas. Residual horizontal velocities of greater magnitude are found west and/or north of these two boundaries, and they are due mostly to interactions among tectonic plates with localized pockets due to other geophysical phenomena. Large residual vertical velocities, some with values exceeding 30 mm/yr, are found in southeastern Alaska. The uplift occurring here is due to present-day melting of glaciers and ice fields formed during the Little Ice Age glacial advance that occurred between 1550 A.D. and 1850 A.D.
GEOSCAN ID300844