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TitreMultiscale geomorphological classification of the seafloor in an active continental volcanic setting - Bay of Plenty, New Zealand
TéléchargerTéléchargement (publication entière)
AuteurLamarche, G; Guntz, M; Mackay, K; Pallentin, A; Rowden, A
SourceProgram 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. 74, https://doi.org/10.4095/305882 (Accès ouvert)
LiensGeoHab 2017
Année2017
ÉditeurRessources naturelles Canada
Réunion2017 GeoHab: Marine Geological and Biological Habitat Mapping; Dartmouth, NS; CA; mai 1-4, 2017
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/305882
Mediaen ligne; numérique
Référence reliéeCette 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
Formatspdf
Lat/Long OENS 175.5000 178.5000 -37.5000 -38.0000
Sujetstechniques de cartographie; océanographie; milieux marins; études côtières; conservation; organismes marins; écologie marine; gestion des ressources; peuplements biologiques; etudes de l'environnement; écosystèmes; benthos; bathymétrie; topographie du fond océanique; configurations lit; levés géophysiques; levés acoustiques marins; levés au sonar; sonar latéral; photographie; établissement de modèles; caractéristiques sous-marines; sismicité; géologie du substratum rocheux; caractéristiques structurales; failles; volcanisme; events hydrothermaux sous-marins; biologie; applications de système d'information géographique; géologie marine; géologie des dépôts meubles/géomorphologie; géologie de l'environnement; géophysique
ProgrammeGéoscience de la gestion des océans, Géoscience en mer
Diffusé2017 09 26
Résumé(disponible en anglais seulement)
Detailed knowledge of the physical and biological conditions of the seafloor is key to the development of economic, environmental and cultural activities in the marine environment. Full coverage information on substrate and benthic habitat relies almost exclusively on acoustic remote-sensed data provided by multibeam echosounders, subsequently ground-truthed using visual observations and physical sampling. Predictive habitat mapping provides a means to develop models of seafloor habitat in regions where only acoustic data are available.
The diverse geomorphology and benthic ecology in the Bay of Plenty makes the area a useful case study for developing regional and local models of benthic habitat: water depths range 0 - 3300 m with geomorphological features including channel, canyons, seamounts and ridges at a variety of scales. Active geology is demonstrated by the intense seismicity, dense fault network, and ubiquitous submarine volcanic activity that results in venting hydrothermal fluids at, for example, the Calypso vent fields. This environment provides habitat for benthic communities, whose structure and distribution can be expressed at a variety of scales.
Multiscale seafloor topography classification is strongly dependent on the quality of the bathymetric data. In this study we combined multibeam echosounder (MBES) data from a variety of systems, data collected on transit, and dedicated scientific and hydrographic surveys, with data from the New Zealand national bathymetry model derived from historic and modern single-beam echosounder (SBES) data for areas without MBES coverage.
We integrated marine geological and oceanographic information in Benthic Terrain Models of the Bay of Plenty and the Calypso vent fields, i.e. at regional and local scales using the ESRI ArcGIS Benthic Terrain Modeler (BTM) tools, with a modified classification catalog to suit the highly variable terrain of the Bay of Plenty. Classification of the geomorphology was based on a number of morphometric parameters (e.g., slope, Bathymetric Positioning Index, curvature, rugosity) derived from the bathymetry gridded at 25 m for the region, and 5 m for the Calypso vent fields.
A 13 geomorphological class catalogue was used that differentiated large (broad slopes, basins) and local (knolls, narrow ridges/valleys) scale features. Seventy-seven percent of the 25,000 km2 study area is broad flat, the remainder is dominated by local ridges and narrow depressions. Ground-truthing data will enable us to associate biological observations to each class, and predict benthic habitat in region where no observations exist.
GEOSCAN ID305882