Monterey Bay, CA (P080) Bathymetric Digital Elevation Model(30 meter resolution) Derived From Source Hydrographic SurveySoundings Collected by NOAA

Bathymetry for Monterey Bay was derived from sixteen surveys containing60,776 soundings. No surveys were omitted. The average separationbetween soundings was 95 meters. The surveys dated from 1932 to 1996.The older surveys fell along the shoreline and the more recent surveyscovered the deep canyon. The total range of sounding data was 0.6 metersto -863.2 meters at mean low water. A mean high water value of 1.1 meterswas assigned to the shoreline. Eleven points were found that were notconsistent with the surrounding data. These were removed prior to tinning.DEM grid values outside the shoreline (on land) were assigned null values(-32676).Monterey Bay has ten 7.5 minute DEMs and two one degree DEMs. The 1degree DEMs were generated from the higher resolution 7.5 minute DEMswhich covered the estuary. A Digital Elevation Model (DEM) contains aseries of elevations ordered from south to north with the order ofthe columns from west to east. The DEM is formatted as one ASCIIheader record (A- record), followed by a series of profile records(B- records) each of which include a short B-record header followedby a series of ASCII integer elevations (typically in units of 1centimeter) per each profile. The last physical record of the DEM isan accuracy record (C-record).The 7.5-minute DEM (30- by 30-m data spacing) is cast on theUniversal Transverse Mercator (UTM) projection. It provides coveragein 7.5- by 7.5-minute blocks. Each product provides the samecoverage as a standard USGS 7.5-minute quadrangle but the DEMcontains over edge data. Coverage is available for many estuaries ofthe contiguous United States but is not complete.