A Biogeographic Assessment off North/Central California

Analyses/Maps

Environmental Variables

HIGH RESOLUTION BATHYMETRY

About this map:
This map displays a bathymetric model of the northern/central California study area. Prominent bottom features, such as canyons, seamounts, banks, and other large scale geological formations, are evident at the scale presented.

Data Sources:
NOAA/NOS hydrographic survey data available from the National Geodetic Data Center (NGDC) and Monterey Bay Research Institute (MBARI) - multibeam data.

Download Bathymetry and Elevation ArcView Grids

Methods:
Results were calculated from 3 arc second bathymetry (nominally 70 m) derived from NGDC and MBARI data sources. All available multibeam data were used. Hydrographic survey data (echo soundings) were eliminated from the calculation if it occurred coincidentally with multibeam information. Vertical and horizontal correction was performed on all data prior to modeling. All data were triangulated and rasterized using Vertical Mapper extension of MapInfo 6.5. Cell size varied throughout the study area, but significant portions were mapped at 70 m2 grid cell resolution.

Results and Discussion:
The study area contains two distinct bathymetric regions. The northern portion of the study area, from Monterey Canyon northward, is characterized by having a broad continental shelf (15-50 km wide), while the southern region has a very narrow shelf with rapidly increasing depth close to shore. This pattern results in significantly shallower mean depth for Cordell Bank (394.9 m) and Gulf of the Farallones (265.3 m) sanctuaries compared to the mean depth within Monterey's sanctuary (876.9 m). For a more detailed description of bathymetric features see the explanation of the study area.

This map is not intended for navigational purposes. Some areas on this map are created from old or sparse data, and are not necessarily representative of the actual seafloor characteristics.