LITH5.0: a revised crustal model for Canada based on Lithoprobe results
Bibliographic record
Abstract
During the last 15 yr, numerous seismic refraction experiments have been conducted over the Canadian landmass, most as part of the Lithoprobe initiative. The new results provide the basis for revising existing global models of crustal structure, e.g. CRUST5.1 (Mooney 1998), which do not incorporate the new Lithoprobe data. The crustal model discussed here, LITH5.0, combines the Lithoprobe and CRUST5.1 data to provide better constraints on crustal structure in Canada. The objectives of the study are to: (1) compile available new data into a single, consistent database of crustal thickness and velocity, including the uppermost mantle (Pn) velocity; and (2) to construct a revised 5°× 5° crustal model of the Canadian landmass, in a format that is generally compatible with existing global models. The Lithoprobe results suggest a 5.5 km average root mean square (rms) crustal thickness difference between LITH5.0 and CRUST5.1. Even with the incorporation of the new data, the geographic coverage in north and central Canada remains sparse. The new model does not explicitly incorporate geological constraints, but instead relies on spherical spline interpolation for extrapolating values into regions that lack control. To illustrate the implications of this new crustal model, we use LITH5.0 to correct for the isostatically compensated crustal heterogeneity in order to obtain improved estimates of the dynamic surface topography. The latter provides important constraints on the density structure of the uppermost mantle.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".