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TitleNAD83v70VG: a new national crustal velocity model for Canada
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorRobin, C M I; Craymer, MORCID logo; Ferland, R; James, T SORCID logo; Lapelle, E; Piraszewski, M; Zhao, Y
SourceGeomatics Canada, Open File 62, 2020, 70 pages, Open Access logo Open Access
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
File formatreadme
File formatpdf; rtf; xlsx (Microsoft® Excel®)
ProvinceCanada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS1; 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
AreaCanada; United States of America; Greenland; Denmark
Lat/Long WENS-154.0000 -40.0000 85.0000 39.0000
Subjectsgeophysics; Science and Technology; Nature and Environment; geodesy; geodetic networks; crustal models; crustal movements; crustal uplift; isostasy; geodynamics; modelling; satellite geodesy; software; geostatistics; NAD83(CSRS); Canadian Spatial Referencing System; North American Datum Of 1983 (Nad83); Geographic data; Geographic information systems; global navigation satellite systems (GNSS); Methodology
Illustrationsgeoscientific sketch maps; location maps; time series; tables; plots
ProgramCanadian Geodetic Survey Geodetic Analysis and Development - Reference frames and Earth dynamics
Released2020 11 30
AbstractA national-scale crustal velocity model has been developed for Canada as part of the current realisation of NAD83(CSRS), delivered as a set of 3 national grids, for each of the North, East and Up (N, E and U) components. It is used to propagate coordinates to different reference epochs, and to support scientific studies such as natural hazards, climate change, and groundwater change. The previous velocity model was based on continuous and campaign GPS data between 1994 and 2011.3. The new model includes new stations in key areas, six more years of data (to the end of 2017), and newly reprocessed historical data using the latest software and GPS products. We include data from continuous GPS sites in Canada, the northern portions of the US, all of Greenland, and a set of globally distributed sites used to define the reference frame; and from repeated high accuracy campaign surveys in Canada. A new type of model is introduced for the vertical grid. It incorporates GPS observations with the crustal uplift predictions of Glacial Isostatic Adjustment (GIA) and elastic rebound models, which are especially important in areas with sparse coverage. Gridded uncertainty estimates are provided for each component of NAD83v70VG.
Summary(Plain Language Summary, not published)
The Canadian Geodetic Survey of Natural Resources Canada maintains the Canadian Spatial Reference System (CSRS), the fundamental standard for the measurement of latitude, longitude, and elevation in Canada. On a dynamic planet these coordinates are constantly changing. NRCan uses a network of GPS sensors to monitor crustal motion in Canada, and provides high-precision positioning stakeholders a gridded velocity model to keep coordinates precise over time. A new version of the model was introduced in 2019, using up to date data at existing and new sensor sites. New in this version of the model, GPS observations are integrated with geophysical models to account for crustal motion not observed by the sensor network. This is particularly important in northern Canada, where the sensor network is sparse and vertical crustal motion has been strongly affected by post-glacial rebound since the end of the last Ice Age. This paper describes the methods used in the development of the new velocity model.

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