Production rates and radiocarbon signatures of greenhouse gases from incubations of thermokarst lake sediments in Kuujjuarapik
Bibliographic record
Abstract
This dataset presents results from anoxic incubations of thermokarst lake surficial sediments from northern Quebec (Kuujjuarapik) across a range of temperatures (4, 12, and 22˚C). We measured methane (CH4) and carbon dioxide (CO2) production rates and associated radiocarbon values. In the summers of 2019 and 2021, sediment samples were collected from five lakes two different sites. The first lake (KWK1), located in the KWK valley, was formed due to mineral soil permafrost collapse. The remaining four lakes are situated in the SAS2 peatland. Permafrost in this region is found in palsa permafrost mounds, while permafrost-free areas consist of bogs with peat moss and sedges, along with numerous thermokarst lakes. The lakes sampled include SAS2X, SAS2C, SAS2A, and SAS2B. Sampling involved collecting the upper 5–10 cm of surface sediments from the central regions of the lakes using an Eckman dredge. In 2019, samples were stored in sealed 0.5 L Nalgene bottles, while in 2021, Whirlpak bags were used. The sediments were stored at 4 °C until utilized for the subsequent incubation experiments. Experiments were prepared by combining ~10 grams of homogenized sediment from the sites with 20 mL of M9 growth medium in anaerobic conditions. The slurries were sealed in serum bottles, flushed with pure Nitrogen, and incubated at three temperatures (4 °C, 12 °C, and 22 °C) with duplicates or triplicates for each site. Controls were added to assess abiotic CH4 production and verify the absence of CH4 sources other than sediment. Incubations were terminated when there was sufficient CH4 for radiocarbon measurements, approximately 1 mg of carbon or 3% CH4 in the headspace. Three sets of incubations were conducted. The first involved sediment collected in August 2019 from SAS2B, SAS2C, and KWK1 lasting 105 days. The second set, assembled eight months later due to COVID-19 restrictions, used the same sediment and extended the incubation to 219 days. The third set utilized sediment collected in August 2021 from SAS2X, SAS2C, and SAS2A for 260 days. Results in this dataset include then, production rates of CH4 and CO2, radiocarbon values of CH4 and CO2, and geochemical and isotopic characteristics of the sediment used for the incubations.
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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 | 0.000 | 0.001 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".