We map the regional physiography and surficial lithology (Surficial Geologic Habitat or
SGH) over the continental margin of Oregon. This thesis develops, describes, and
implements an iterative interpretive method to map seafloor habitat types from disparate
geological and geophysical datasets including: bathymetric images, sidescan sonar
images, seismic reflection profiles, sediment samples, geologic maps of structure, and
observations from submersibles. An indirect technique for the assessment of map
accuracy or habitat type misidentification error is also explored and used to derive
supplemental maps of varying interpretative confidence, or "quality".
The geological and geophysical datasets used to produce the SGH maps of the Oregon
margin are by their nature patchy, and form an irregular mosaic of variable data density
and quality. Uniform sampling of continental margins does not yet exist, thus these
maps are an attempt to glean as much information as possible from the framework of
existing data. In any given area the quantity and quality of data available varied
considerably, and required a flexible method of interpretation based on this availability.
The integrated interpretative GIS techniques are developed to facilitate mapping
geologic habitat types over this region of discontinuous and patchy seafloor data.
The SGH map and thematic map accuracy assessment support improved habitat-based
inventory and assessment methods. They also serve as habitat reference materials for
marine resources management and planning activities at local to national scales. SGH
and data quality maps are incorporated as thematic layers within a broader habitat
geodatabase for west coast groundfish and are directly applied for modeling Essential
Fish Habitat (EFH) for these species.