Bibliographic record
Abstract
Pn Spectra are collected from three PASSCAL seismic experiments in the Tibetan Plateau (TP) over four path groups. The first and second path groups run southward from the eastern Tarim Basin to stations in north and south central Tibet. The third and fourth path groups form two NNE-oriented profiles in the eastern TP. Events recorded by the first 2 path groups also are recorded by the Khyrghistan network (KNET) to the west. A comparison of Pn spectra averaged over both path groups and KNET reveal that mantle lid under the TB attenuates P waves more severely than central Asia, particularly at high frequencies (> 1 Hz). Apparent Q(sub 0) and eta (Pn Q at 1 Hz and its frequency dependence, respectively) are estimated with a simplified geometrical spreading. Over path group 1 that heavily samples northern TB, Q(sub 0) and eta are estimated to be 183 +/- 33 and 0.3 +/- 0.1, respectively. Over path groups 2 and 3 that sample either a mixture of northern and southern Tibet or eastern Tibet, the estimated Q(sub 0) and eta are between approx. 250 and 270 and 0.0 and 0.1, respectively. Over the fourth path group that samples the easternmost TB the respective estimates are 374 +/- 51 and 0.3 +/- 0.1. A comparison of Pn attenuations in continental regions suggest that they are similar in the easternmost TB, Central Asia, Scandinavia, and the Canadian shield. Northern Tibet has the highest attenuation at all frequencies. Pn attenuation under southern Tibet is similar to the shield regions at low frequencies (</= 1Hz), and similar to northern Tibet at higher frequencies (up to 4 Hz). It appears that a southward increase in the lid temperature causes increases in both Pn velocity and low-frequency Pn Q, but causes no change in high-frequency Pn Q. This phenomenon may be best explained by a propagation mechanism in which Pn traverses the lid as a single, deep refraction at low frequencies, and as multiply bounced and scattered ("whispering-gallery") rays at high frequencies.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
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".