Palaeoenvironmental history of the last six centuries in the Nettilling Lake area (Baffin Island, Canada): A multi-proxy analysis
Bibliographic record
Abstract
The Baffin Island region in the eastern Canadian Arctic has recently experienced a rapid warming, possibly unprecedented in millennia. To investigate the response of freshwater environments to this warming and place it in a secular perspective, we analyzed a 90-cm-long sediment core from Nettilling Lake, the largest lake of the Canadian Arctic Archipelago. The core was taken from a part of the lake basin that receives meltwater and sediment inputs from the nearby Penny Ice Cap. The core time scale, established using 137 Cs and palaeomagnetic techniques, spans an estimated 600 years. A multi-proxy approach was used to document changes in the physical, chemical, and biological properties of the sediments. We found evidence for a relatively warm period (mid/late 15th century to mid/late 16th century) during the early part of the ‘Little Ice Age’ (LIA), characterized by high sedimentation rates and laminations. This was followed by colder, drier, and windier conditions corresponding to the coldest phase of LIA and coinciding with the latest and most extensive period of regional ice cap expansion (early 16th to late 19th centuries). A rapid warming occurred at the beginning of the 20th century. Variations in titanium (Ti) content in the core, a proxy for detrital sediment inputs, showed good agreement with reconstructed secular variations in summer melt rates on Penny Ice Cap between the mid-14th century and the present-day, providing supporting evidence for a climatic–hydrological connection between the ice cap and Nettilling Lake.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 teacher head, 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".