| Titre | CMECS map for an area of the Oregon Outer Continental Shelf relevant to renewable energy |
| Télécharger | Téléchargement (publication entière) |
| Auteur | Cochrane, G R; Hemery, L G; Henkel, S K; Schroeder, D M |
| 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. 43, https://doi.org/10.4095/305840 (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/10.4095/305840 |
| 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 |
| Lat/Long OENS | -131.0000 -123.5000 46.5000 42.0000 |
| Sujets | techniques de cartographie; océanographie; milieux marins; études côtières; conservation; organismes marins; écologie marine; gestion des ressources; écosystèmes; ressources énergétiques; marges
continentales; plate-forme continentale; topographie du fond océanique; bathymétrie; propriétés hydrologiques; levés géophysiques; levés acoustiques marins; levés au sonar; levés sismiques marins; levés de reflexion sismiques; photographie; sédiments
marins; benthos; glissements; structures de glissement; trous; biotopes; biomes; biologie; énergie renouvelable; énergie éolienne; géologie marine; stratigraphie; géologie des dépôts meubles/géomorphologie; géologie de l'ingénieur; Histoire et
archéologie; géologie de l'environnement; Santé et sécurité |
| Programme | Géoscience en mer, Géoscience de la gestion des océans |
| Diffusé | 2017 09 26 |
| Résumé | (disponible en anglais seulement)
In 2014 the USGS and the BOEM entered into an Intra-agency agreement to map an area of the Oregon Outer Continental Shelf (OCS) off of Coos Bay, Oregon under
consideration for development of a floating wind energy farm. The BOEM requires seafloor mapping and site characterization studies in order to evaluate the impact of seafloor and sub-seafloor conditions on the installation, operation, and structural
integrity of proposed renewable energy projects, as well as to assess the potential effects of construction and operations on archaeological resources. The mission of the USGS is to provide geologic, topographic, and hydrologic information that
contributes to the wise management of the Nation's natural resources and that promotes the health, safety, and well-being of the people.
For the Oregon OCS study the USGS acquired multibeam echo sounder (MBES) and seafloor video data surrounding
the proposed development site, a 95 km2 area 15 miles offshore of Coos Bay, Oregon. The USGS subsequently produced a bathymetry digital elevation model and backscatter intensity grids. Analysis of the video data was conducted by OSU and a Coastal and
Marine Ecosystems Classification Standard (CMECS) geoform and substrate component interpretation of the MBES data was conducted by the USGS.
Though combinations of mud and sand dominate the surficial substrate there is a diverse assortment of
geomorphologic features related to geologic processes. Video supervised numerical analysis of the MBES backscatter intensity data and vector ruggedness derived from the MBES bathymetry data was used to produce a substrate model for the study area
called a seafloor character raster. The sea floor character raster consists of three substrate classes, soft-flat areas, hard-flat areas and hard-rugged areas that were used to generate CMECS substrate attributes. For substrate polygons that had
video grain size information a finer level of CMECS grain size was added to the map. CMECS geoform attributes were produced using depth, slope and benthic position index classes to delineate geoform boundaries. Seven geoforms were identified in this
process including ridges, slump scars, slump deposits, basins and pockmarks. There is one anticlinal ridge where bedrock is exposed, a slump and associated scarps, and pockmarks. Pockmarks are seen in the form of fields of small pockmarks (< 100
metres diameter), a lineation of large pockmarks with methanogenic carbonates, and areas of large pockmarks that have merged into larger variously shaped depressions. The slump appears to have originated at the pockmark lineation. Existing
multichannel seismic data was examined to attempt to identify crustal faults associated with pockmark areas and lineations. Faults related to anticlines could be inferred by displacement of reflecting strata but structures related to pockmarks could
not be resolved.
Statistical analysis of the video data for correlations between substrate, depth and biotic assemblages by OSU resulted in the identification of seven biomes, three hard bottom biomes and 4 soft bottom biomes. A biotope map was
generated using the seafloor character raster and the substrate and depth values of the biomes. Hard substrate biotopes were small in size and were located primarily on the ridge and in pockmarks along the pockmark lineation. The soft bottom biotopes
consisted of large contiguous areas delimited by isobaths. |
| GEOSCAN ID | 305840 |
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