COMPARISON OF THE 2-TERM AND 3-TERM AVO APPROXIMATIONS FOR SEISMIC DATA IN PENOBSCOT AREA, NOVA SCOTIA
Bibliographic record
Abstract
The purpose of this study is to compare different AVO approximations and support these results through pre-stack inversion. A 3D seismic survey in Penobscot area was used to conduct the study. The data quality was very poor, so the enhancement process was applied to the data to increase quality. The data were filtered by various the Parabolic Radon Transform time ranges which do not disturb real AVO characteristics while removing noise, particularly the interference from multiples. The 2-term (“Shuey”) and the 3-term (“Aki-Richards”) approximations were run on the data. Similar AVO characteristics were obtained for both approximations for the same filtering parameters of the Parabolic Radon Transform. In order to check AVO approximations results, pre-stack trace inversion was applied to one of the Parabolic Radon Transform results, solving for two parameters (acoustic impedance and shear impedance) and for three parameters (Vp, Vs, and density). In order to further investigate the nature of pre-stack data, these inversions were applied to the data to maximum angles of incidence of 30° and 45°. The inversion results show no significant differences for P-impedance or, S-impedance, regardless of the angle limitations or number of terms solved for, and no significant variations in density for angle range covered. It was found that there is a strong correlation between P-wave velocity and density. It was also observed that lack of S-wave log caused similar results for inversion.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".