| Titre | Seafloor mapping in a hypertidal setting: Minas Basin, Nova Scotia, Canada |
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| Auteur | Todd, B J |
| Source | 2022 p. 52 |
| Liens | Online - En ligne
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| Image |  |
| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20220006 |
| Réunion | 2022 GeoHab Conference; Venice; IT; mai 16-20, 2022 |
| Document | publication en série |
| Lang. | anglais |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Nouvelle-Écosse |
| Région | Baie de Fundy |
| Sujets | Bassin de Minas ; Sciences et technologie; Nature et environnement; géologie marine |
| Illustrations | cartes de localisation |
| Programme | Géosciences marines pour la planification spatiale marine |
| Diffusé | 2022 05 16 |
| Résumé | (disponible en anglais seulement)
The Bay of Fundy is a large embayment located on the east coast of Canada between the provinces of Nova Scotia and New Brunswick. At the northeastern end of the
Bay of Fundy lies the hypertidal Minas Basin that exhibits the highest recorded tides in the world of 17 m. As a result of the hypertidal nature of the Fundy-Minas system, strong currents are generated, reaching a maximum speed of approximately 5 m/s
in Minas Channel at the entrance to Minas Basin. Over the past century, investigations in this region has been episodic, with peak activity associated with proposals for large infrastructure construction (barriers and turbines) associated with tidal
power development by harnessing the currents. Concern that physical, chemical and ecological changes are taking place in the unique coastal environment Fundy-Minas system has lately generated renewed research. Much of the Minas Basin is less than 20
m deep and its waters are turbid. The extreme tidal range exposes a large area of intertidal mudflats and salt marshes around the periphery of the basin. The mudflats and marshes host high densities of invertebrates and are a food source for large
populations of migrating shorebirds. This intertidal zone presents a particular surveying challenge to the collection of water depth data. Historically, intertidal zones were not surveyed due to the danger involved in operating surface vessels in
coastal areas that dry between tides. To obtain bathymetric data for this study, the intertidal portion of Minas Basin was mapped during periods of low tide using aircraft-mounted LiDAR (see image below). The mapping revealed the complex topography
of the mudflats and the dynamics of sand bedforms in energetic settings. The nature of the seabed and the subsurface of the Minas Basin is poorly understood; the only known geophysical profiles date to the mid-1960s. The ultimate objective of the
research program is to map the entire seabed of Minas Basin using multibeam sonar either from a surface vessel or from an autonomous underwater vehicle. However, in this hypertidal setting, any vessel/AUV mapping campaign requires an upper
bathymetric limit to which to survey. Thus, the first step in reaching complete seabed coverage was to map to the lowest possible "depth" (i.e. exposed seabed) during periods of low tide. |
| Sommaire | (Résumé en langage clair et simple, non publié)
La baie de Fundy est une grande baie située sur la côte est du Canada entre les provinces de la Nouvelle-Écosse et du Nouveau-Brunswick. À
l'extrémité nord-est de la baie de Fundy se trouve le bassin Minas. Afin d'obtenir des données bathymétriques pour cette étude, la partie intertidale du bassin Minas a été cartographiée pendant les périodes de marée basse à l'aide de lasers
d'aéronefs. La cartographie a révélé la topographie complexe des vasières et la dynamique des formes de lit de sable dans des contextes énergétiques. |
| GEOSCAN ID | 329938 |
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