Holocene paleohydrological variability and change in the Timmins region, Ontario, Canada
Notice bibliographique
Résumé
Climate models suggest that temperatures will increase by at least 1.5-2°C by the end of the 21st century due to climate change. Similar patterns were observed during the mid-Holocene when the American prairie region displayed drier conditions while the American northeast was wetter. Published pollen records in northeast Ontario give conflicting perspectives and, it remains poorly understood whether this area was drier or wetter during this period. The overall objective of this dissertation is to better understand paleohydrological variability and change over the Holocene in the Timmins region of Ontario and to investigate the role of groundwater connectivity in how lakes respond to hydroclimatic changes. \n \nBased on lake-water geochemistry, Chapter 2 shows that elevation is the main control on lake-water-groundwater interactions at the landscape level and that the water balance in lakes varied between field campaigns with upland lakes showing a greater sensitivity to short-term and seasonal hydroclimatic change as well as to evaporative drawdown. \n \nIn order to understand how water levels varied over a long-term perspective, sediment cores were retrieved from two adjacent lakes: one located upland and limited to the local groundwater system (Irrigation Lake); and the other positioned at a lower elevation and embedded in a regional aquifer (Charland Lake). Chapters 3 and 4 aim at reconstructing past hydrological conditions using pollen along with carbonate stable isotopes, and sediment elemental chemistry respectively. Both chapters concluded that water levels were lower between 9,500 and 6,500 years Before Present (BP) after which they rose rapidly between 6,500 and 5,200 years BP to reach stable water highstands between 5,200 and 1,600 years BP, after which levels decreased slightly while remaining relatively high from 1,600 years BP to present. This implies that northeast Ontario is synchronous with the American northeast and asynchronous with the American prairie region. However, those changes were less pronounced in Charland Lake, indicating that buffering from groundwater dampens even sustained long-term hydroclimatic change, in comparison to the higher elevation record from Irrigation Lake. This suggests that lakes will respond differentially to future climate change based on their degree of connectedness to the groundwater system.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 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 tête enseignante, 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 ».