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Record W4416441573 · doi:10.1016/j.geomat.2025.100087

The new NAD83v80VG velocity model using an updated velocity field for Canada

2025· article· en· W4416441573 on OpenAlexaffvenueabout
Karen M. Simon, Jason Bond, M. Craymer, Babak Amjadiparvar, Michael J. Bremner, E. Lapelle, Yanlai Zhao

Bibliographic record

VenueGEOMATICA · 2025
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicGeophysics and Gravity Measurements
Canadian institutionsGeological Survey of Canada
Fundersnot available
KeywordsGNSS applicationsPost-glacial reboundReference frameDeformation (meteorology)Geodetic datumLevellingScale (ratio)

Abstract

fetched live from OpenAlex

An improved national scale crustal velocity model has been developed for Canada that is part of an ongoing effort to update the realization of the Canadian Spatial Reference System (CSRS) to NAD83(CSRS) v8 and to support the implementation of the new North American Terrestrial Reference Frame of 2022 (NATRF2022). The new model is based on a reprocessing of all GNSS data to the end of 2023 and includes data from active GNSS stations throughout Canada, repeated high accuracy Canadian campaign data, as well as continuous GNSS data from Alaska, the northern contiguous United States, and Greenland. Like the previous version, the updated velocity model is a ‘hybrid’ combination of geophysical model predictions constrained to GNSS crustal velocity estimates, a feature that is particularly useful in regions with large deformation signals and/or sparser GNSS data coverage (i.e., much of northern Canada). The geophysical model inputs are predictions from glacial isostatic adjustment (GIA) and elastic deformation models that estimate the vertical velocity signal from present-day melting of ice sheets and glaciers. The GIA and present-day mass signals are combined with the GNSS velocities to provide crustal velocity and uncertainty estimates for the north, east and vertical components. For most of the study area, the predicted uncertainties are <1 mm/yr. The resulting hybrid velocity model is a critical part of the CSRS that enables users to propagate their coordinates to different reference epochs and can also be used to support studies of sea level change and natural hazards. • An updated velocity field for Canada is derived from GNSS measurements • The measured velocities and geophysical models generate a crustal velocity model • The updated national-scale velocity model is termed NAD83V80VG • The velocity model includes vertical and horizontal motion as well as uncertainties

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.746
Threshold uncertainty score0.422

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0010.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.028
GPT teacher head0.239
Teacher spread0.211 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2025
Admission routes3
Has abstractyes

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