Bibliographic record
Abstract
It has come to our attention that the least-squares estimator we proposed in a recent paper to recover bulk crustal P velocity, VP, and P velocity/S velocity ratio, R, of the crust from traveltimes of scattered teleseismic phases, is inconsistent. That is, in the presence of errors, estimates of R will be biased downwards and estimates of VP will be biased upwards from their true values. In this note we supply bias corrections for both quantities that depend upon an estimate of the variance in a ratio of traveltime sums, and demonstrate their validity through comparison with estimates based on a two-parameter grid search. Application to station HYB yields R= 1.756 ± 0.005, VP= 6.2 ± 0.1 km s−1, after correction of a systematic traveltime picking error that had affected our previous results. In addition, we provide an alternative waveform-stacking approach that involves a 2-D grid search over R and VP followed by a 1-D line search over crustal thickness H. An estimate of the direct Ps conversion time is required, and results from station HYB are consistent with those produced using traveltimes alone.
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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 | 0.005 | 0.031 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".