Bibliographic record
Abstract
Several analytical techniques have been used to derive crustal structure from the data obtained in the 1963 Lake Superior seismic experiment conducted as a part of the United States and Canadian programs in the Upper Mantle Project. The Lake Superior region was found to have an unusual and rapidly varying crustal structure in comparison with the Canadian shield area surrounding it. In general, under the lake, a high-velocity crust (6.67 km/sec) was found beneath 4 to 6 km of Keweenawan sediments and volcanics. The uppermantle velocity of 8.07 km/sec agrees closely with values found previously in adjacent areas. The depth to the M discontinuity varies from about 20 km in the area just west of the lake to 55 km or more in the eastern half of the lake. These values are among the most extreme yet observed in North America. A number of second-order structural features were also found in the M discontinuity. These differences and the major structures persist for all reasonable assumptions about the velocity-depth function. Of the techniques employed, the standard reverse-profile technique is poor for this complex structure, and the apparent velocity measurements provided limited information about the velocity-depth function. The extended time-term technique developed and used here produced the most complete structural picture, and the general features of this structure are confirmed by a dip projection method derived from apparent velocity data.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".