| Titre | Mapping of complex structures: high resolution 3D renditions of vertical coral reefs |
| Télécharger | Téléchargement (publication entière) |
| Auteur | Robert, K; Huvenne, V A I; Jones, D O B; Marsh, L; Georgiopoulou, A |
| Source | Program and abstracts: 2017 GeoHab Conference, Dartmouth, Nova Scotia, Canada; par Todd, B J; Brown, C J; Lacharité, M; Gazzola, V; McCormack, E; Commission géologique du Canada, Dossier public 8295,
2017 p. 100, https://doi.org/10.4095/305919 (Accès ouvert) |
| Liens | GeoHab 2017
|
| Année | 2017 |
| Éditeur | Ressources naturelles Canada |
| Réunion | 2017 GeoHab: Marine Geological and Biological Habitat Mapping; Dartmouth, NS; CA; mai 1-4, 2017 |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/305919 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans Todd, B J;
Brown, C J; Lacharité, M; Gazzola, V; McCormack, E; (2017). Program and abstracts: 2017 GeoHab Conference, Dartmouth, Nova Scotia, Canada, Commission géologique du Canada, Dossier public 8295 |
| Formats | pdf |
| Sujets | techniques de cartographie; océanographie; milieux marins; études côtières; conservation; organismes marins; écologie marine; gestion des ressources; peuplements biologiques; etudes de l'environnement;
écosystèmes; benthos; récifs; caractéristiques sous-marines; canyons sous-marins; glissements de terrain; méthodes photogrammétriques; photographie; établissement de modèles; Coraux; biologie; géologie marine; géologie des dépôts
meubles/géomorphologie; géologie de l'environnement |
| Illustrations | photographs; 3-D images |
| Programme | Géoscience de la gestion des océans, Géoscience en mer |
| Diffusé | 2017 09 26 |
| Résumé | (disponible en anglais seulement)
Vertical and overhanging walls in complex deep-sea environments can harbour high biodiversity and host vulnerable marine ecosystems, to which they provide
natural protection from certain human activities (e.g. trawling) as a result of their geometry. As such, it is important to understand their ecology, but traditional ship-board multibeam echosounders cannot adequately replicate the complete 3D
structure of vertical habitats, and towed video systems are challenging to operate in these rugged environments. In this study, we employed novel photogrammetry techniques (structure from motion, SfM) to create 3D representations of ROV video
transects along vertical walls on the Rockall Bank Slide Complex and the Whittard Canyon, Northeast Atlantic. SfM allows such reconstructions to be created using a single camera moving around a scene, dispensing from more complex stereo-pair
acquisition systems and allowing previously collected footage to be re-examined. With these reconstructions, it was possible to interact in 3D with extensive sections of video footage which cannot otherwise be visualized in their entire context. Once
georeferenced, these models allowed for positioning of individual organisms at very fine scales and terrain variables could be derived on scales similar to those experienced by megabenthic individuals (<1cm for photogrammetry). The finer resolutions
now achievable through these advances allowed differences in terrain conditions selected by different morphospecies of cold-water corals to be quantified. In addition, since the SfM reconstructions retained colours, they were employed to separate and
quantify in 3D (e.g. surface area, volume) live coral colonies versus dead framework. These new technologies allow us, for the first time, to map the physical 3D structure of previously inaccessible habitats at very high resolutions and demonstrate
the complexity and importance of vertical walls.
This work is part of the ERC CODEMAP project (Starting Grant no 258482) and data were collected during the CODEMAP2015 cruise and the SORBEH expedition (Marine Institute, Ireland). |
| GEOSCAN ID | 305919 |
|
|