Thickness and material properties of multi-year ice sampled during the CAT study, August 2007
Notice bibliographique
Résumé
A field program was carried out to measure the properties of multi-year ice in the high Arctic. Thicknesses are reported for multi-year ice floes in Nares Strait (9 floes), Norwegian Bay (1 floe) and Lady Anne Strait (1 floe). The diameter of the 11 floes ranged from 175 m to 7.5 km. Multi-year ice in mainstream Nares Strait drifted south at 1.38 to 2.04 km/hr in a near-straight trajectory. The trajectories of two floes were mapped using satellite tracking beacons. Floe N06, which had an average thickness of more than 9.5 m but was only about 500 m in diameter, drifted south from Nares Strait until it disintegrated along the eastern coast of Baffin Island almost two months later. Floe N08 was a 2.8 km diameter floe that had an average thickness of more than 8.7 m. The beacon on Floe N08 continues to transmit at the time of writing this report, six months later, off the eastern coast of Baffin Island. More than 1500 m of ice was drilled during the program. Five of the floes had an average thickness of more than 7.7 m, whereas the average thickness of the other six floes ranged from 3.6 to 5.9 m. Standard deviations in thickness on the 11 floes ranged from 0.7 to 3.7 m. The temperature and salinity of the multi-year ice was measured on 4.80 to 5.50 m long cores. The top ice surface was the warmest (-0.9°C) and the interior of the ice was the coldest (-6.9°C). The average temperature of the ice cores ranged from -2.6°C to -4.7°C. Salinities in the uppermost 60 to 100 cm of ice were negligible (0 to 0.2 ‰) and increased to a maximum of 3.6 ‰ towards the interior of the ice. Most of the floes had an average salinity that was quite uniform (1.0 to 1.7 ‰). Borehole strengths were conducted on five floes. The strength was lowest in the uppermost 60 cm of ice (4.0 to 11.5 MPa) and generally increased with increasing depth to 21.5 to 30.6 MPa. The average borehole strength was remarkably consistent on four of the floes (15.9 to 17.5 MP). One floe had an average borehole strength of 23.1 MPa. Comparison of the strength and temperature profiles for the different floes illustrate the inverse relation between temperature and strength. ScanSAR and Standard imagery from RADARSAT-1 were examined to determine whether individual floes were recognizable. Standard imagery was preferred over ScanSAR imagery because of its higher resolution (25 m vs. 150 m). ScanSAR images adequately captured multiyear ice floes upwards of 4.0 km in diameter, but they were not useful for identifying floes less than several kilometers across. In comparison, floes from 400 to 500 m across were detectable in the Standard images, except for when they were masked by the high concentrations of pack ice.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».