The Drift of an Exceptionally-Large Ice Island from the Petermann Glacier in 2008
Bibliographic record
Abstract
In the summer of 2008, an ice island with a surface area of over 20 km² calved from the Petermann Glacier, and drifted south through Nares Strait to Baffin Bay. Ice islands (defined as large pieces of floating ice with a height of about 5 m above sea-level, and an area of from a few thousand sq.m to 500 km² or more, that have broken off an Arctic shelf or floating glacier tongue) and their fragments are a major hazard for offshore structures on the Grand Banks because of their relatively low draft and the difficulty of towing them. The ice island was initially tracked using a combination of Envisat and MODIS imagery, and information on the drift of surrounding sea ice was obtained using Envisat and AMSR-E imagery. Although the ice island calved in mid-July, the ice island did not enter Nares Strait for 3 weeks until a major wind event cleared sea ice from the mouth of the Petermann Fjord. In mid-September, two satellite-tracked ice beacons were deployed on the ice island in northern Baffin Bay northeast of Jones Sound. An ARGOS beacon from the Canadian Ice Service provided a long time series of position data with an accuracy of about 300 m. A prototype Iridium beacon from the Bedford Institute of Oceanography, designed to transmit hourly global positioning system (GPS) fixes with an accuracy better than 10 m, provided about 2 weeks of position data before it malfunctioned. The GPS data initially show inertial oscillations, followed by a grounding event east of Jones Sound lasting for about one day. Bathymetry data suggest that the water depth at the grounding site was about 100 m, however soundings in the area are sparse. The ice island then entered Jones Sound through Glacier Strait, where the bathymetry suggested the ice island had a draft of less than 60-70 m. After remaining in Jones Sound for about 6 weeks, the ice island resumed its southward drift through Lady Ann Strait. The effect of wind forcing on the drift is shown using NCEP/NCAR reanalysis surface winds.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| 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 | 0.000 |
| 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".