Lake Diatoms as Indicators of Late Holocene Climate Variability in the Boreal Region of the Northwest Territories, Canada
Bibliographic record
Abstract
This thesis is comprised of two manuscripts that focus on diatom ecological change through a late Holocene ~ 3300 year record from a 116.2 cm freeze core obtained from Danny's Lake, Northwest Territories, Canada.The diatom results indicate that climate in this region has been relatively stable through the past 3330 cal.yr BP, although three distinct diatom assemblages are recognized.Time-series analysis was also carried out on select diatom species from the Danny's lake sediment core.We correlate the c. 89 and c. 145 year cycles with the 90 -140 year Gleissberg cycle, while the c. 309-year cycle is attributed to the 300-year overtone of the 2115-year Hallstadt cycle.This research is part of a multi-proxy project mandated to determine late Holocene climate variability along the route of the economically important Tibbitt to Contwoyto Winter Road (TCWR), a seasonal ice road that stretches 600 km from Yellowknife to Nunavut.iii Preface Given the enormity of the ice road project, a significant amount of collaboration was involved during this research.Having said that, I was fully involved in setting up and carrying out the research, obtaining data and analyzing results, as well as preparing and writing the multi-author manuscripts presented in this thesis.Specifically, I was responsible for carrying out subsampling, diatom preparation and enumeration, as well as subsequent interpretation of data from the Danny's Lake freeze core.Input from colleagues came in the form of aiding in data analysis and interpretation, as well as reviewing manuscripts.In addition, I had access to age models, loss on ignition and magnetic data, which was shared between all collaborators who are studying the Danny's Lake core.Persons involved in any aspect of this project are acknowledged.
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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 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 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".