Bibliographic record
Abstract
Introduction Approximately 10% of the Earth's surface is covered with ice at present. Most of this ice is in the Antarctic ice sheets (85% of ice by area), another major ice accumulation is on Greenland (12% of ice by area), and the remainder (3% by area) is in glaciers in mountainous regions. Conditions that allow permanent ice to exist (abundant precipitation as snow, and temperatures low enough to permit the snow to accumulate) occur at high latitudes, high altitudes, and near coasts. In addition to the areas of permanent ice, about 20% of the Earth's surface is permanently frozen (e.g., dry continental interiors at high latitudes such as Siberia, Canada, and Alaska). In the past, large areas of the Earth's surface were covered in ice, and such ice ages have occurred at various times throughout Earth history (Figure 17.1). The last few millions of years of the Neogene ice age have been composed of cold periods ( glacials ) with intervening warmer periods ( interglacials ). During the Last Glacial Maximum (LGM) about 18,000 years ago, up to 30% of the Earth's surface was covered in ice, but the Earth is now in an interglacial period. The glacial–interglacial alternations of the past several million years, particularly the latest one, have left a remarkable record on the Earth's surface, and have affected human activities in many ways, perhaps even influencing our evolution.
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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 | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.028 | 0.010 |
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".