Correcting for overburden thickness in airborne gravity data using electromagnetic data
Bibliographic record
Abstract
Summary 5912427new methodology is introduced that corrects airborne gravity data for changes in thickness of glaciolacustrine overburden. The approach is tested for a 35 km-long line from the Quest-West survey in the interior plateau of British Columbia, Canada. A bedrock topography map was created by inverting helicopter transient electromagnetic data. The inversions were conducted independently every 25 m over a 73 × 32 km2 area including the line of interest using a 2-layer near-surface layered earth model and the depth to bedrock was interpolated across the area. The overburden and bedrock were assigned constant densities of 1.80 and 2.67 g/cm3, respectively. The gravity correction methodology employs the typical Bullard corrections with the additional step of using the bedrock topography map to correct for the gravitational acceleration contributed by changes in overburden thickness. Along the line of interest, the maximum overburden thickness reached approximately 300 m, corresponding to a gravity correction of up to 15 mGal.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".