An overview of seismic attenuation in the Charlevoix Seismic Zone, southern Quebec
Bibliographic record
Abstract
We investigate seismic attenuation characteristics of the Charlevoix Seismic Zone. This zone is located ~100 km downstream from Quebec City and is the most seismically active region of eastern Canada. We used earthquake recordings from 8 seismograph stations of the Canadian National Seismic Network (CNSN) across the region. Our dataset is comprised of 584 earthquakes recorded between 1992 and 2022 with magnitudes ranging from 2.0 to 5.4, depths from 0 to 30 km and epicentral distances of 5 to 100 km. This gives a total of 1490 high signal-to-noise (S/N) traces (S/N>5.0) useful for QC calculation (with a maximum ellipse parameter, a2, of 100) across the region. Coda windows were selected to start at tc = 2tS (two times the travel time of the direct S wave), and were filtered at center frequencies of 2, 4, 8, 12 and 16 Hz. Our study reveals a consistent pattern. We find that the highest Q0 (Q at 1 Hz) values are at station A11 (e.g., Q0 of 109), that is the farthest station from the 1663, M~7 earthquake (D=40 km), excluding the new station of CACQ. The lowest Q0 values that we find are at the station A16 (e.g., Q0 of 72) that is the second closest station to the epicenter of the 1663 earthquake (D=16 km) after station A61 (D=10 km). Also, we find the lowest overall average Q0 values at station A16 (e.g., Q0 of 72). In general, Q0 is lower in the vicinity of large earthquakes (Jin & Aki, 1988). Therefore, the low Q0 values at station A16 may suggest that the 1663 earthquake is located slightly southeast of the catalog epicenter, considering high uncertainty associated with historic events. An average for all the data results in a Q relationship of QC = 81f1.06 for the frequency band of 2 to 16 Hz for the entire region.
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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 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.007 | 0.012 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.006 | 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".