Principal bed states during SandyDuck97: Occurrence, spectral anisotropy, and the bed state storm cycle
Bibliographic record
Abstract
Results are presented from 70+ days of nearly continuous in situ acoustic imagery of the nearshore sandy seabed in ∼3‐m mean water depth, at two locations separated by 40‐m cross‐shore distance. The bottom sediments were 150 μm median diameter sand, with nearly identical size distributions at the two locations. Five principal bed states were observed: irregular ripples, cross ripples, linear transition ripples, lunate megaripples, and flat bed. The linear transition and flat bed states were the most frequent, together accounting for 68% of the total time. Bed state occurrence was a strong function of incident wave energy, each bed state occurring within a relatively narrow range of sea‐and‐swell energies. During the 12 major storm events spanned by the record, the bed response was characterized by a repeatable bed state storm cycle, involving four of the five principal states (lunate megaripples did not appear repeatedly, and thus may be a special case), with no obvious dependence of bed state occurrence on prior bed state, or on third‐moment measures of wave nonlinearity. Radial spectra from the rotary acoustic images indicate pronounced differences in the anisotropy of spatial scales for the different bed states, and exhibit onshore‐offshore differences which are likely related to ripple migration.
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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 | 0.000 | 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) | 0.001 | 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".