22166
AFSC/RACE/GAP/Zimmermann: Cook Inlet Grid
AFSC/RACE/GAP/Zimmermann: Cook Inlet Grid
Data Set
Published / External
22291
Groundfish Assessment Program
Project
Completed
2014-04
We assembled 1.4 million National Ocean Service (NOS) bathymetric soundings from 98 lead-line and single-beam echosounder hydrographic surveys conducted from 1910 to 1999 in Cook Inlet, Alaska. These bathymetry data are available from the National Geophysical Data Center (NGDC: http://www.ngdc.noaa.gov), which archives and distributes data that were originally collected by the NOS and others. While various bathymetry data have been downloaded previously from NGDC, compiled, and used for a variety of projects, our effort differed in that we compared and corrected the digital bathymetry by studying the original analog source documents - digital versions of the original survey maps, called smooth sheets. Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. There were six areas where these older surveys were superseded by compilations of reduced-resolution multibeam surveys. We digitized 12,000 features, such as rocky reefs, kelp beds, rocks and islets, adding them to what was originally available, and creating the most thorough source (n = 18,000) of these typically shallow, inshore features. We also digitized 2,418 km of the mainland and 529 km of island shoreline, generally at a resolution of 1:20,000, and digitized 9,271 verbal surficial sediment descriptions from the smooth sheets. The depth surface, shoreline, inshore features, and sediment data sets are mostly produced at a scale of 1:20,000.
The purpose for creating this data set was to provide the best available bathymetry, surficial sediments, shoreline and inshore features of Cook Inlet for predictive, geospatial modeling of marine resources.
Loaded by FGDC Metadata Uploader, batch 5102, 09-10-2014 12:56
The following FGDC sections are not currently supported in InPort, but were preserved and will be included in the FGDC export:
- Spatial Reference Information (FGDC:spref),
- Spatial Data Organization Information (FGDC:spdoinfo)
- Lineage (FGDC:lineage)
This bathymetry grid was created in several steps. First, the bathymetry point data and inshore smooth sheet features, such as rocks and islets, were compared to the source documents - the smooth sheets - and corrected or digitized. Second, the shoreline, which is defined as MHW (Mean High Water tidal datum) was digitized. Third, in six small areas, multibeam data was subsetted at a resolution of 50 m and substituted for the older, less-detailed smooth sheet data. Fourth, the bathymetry point data, which included bathymetric soundings, inshore features with depths or elevations, the MHW shoreline and reduced-resolution multibeam data, were used to create a Triangulated Irregular Network (TIN). The TIN was converted into a grid (raster with 50 meter square pixels). Finally, the grid was trimmed by the shoreline to cover the spatial extent of the study area.
Theme
ISO 19115 Topic Category
elevation
Theme
ISO 19115 Topic Category
imageryBaseMapsEarthCover
Theme
ISO 19115 Topic Category
oceans
Theme
Alaska
Theme
Cook Inlet
Theme
North Pacific Ocean
Theme
bathymetry
Theme
grid
Alaska Fisheries Science Center
Seattle
WA
USA
Data Set
None Planned
Map (digital)
These bathymetry data were proofed, edited and digitized by Mark Zimmermann and Megan Prescott. Funding for much of the work was provided by NOAA's Essential Fish Habitat (EFH), Habitat and Ecological Processes Research (HEPR) through the Alaska NMFS Regional Office. B. McMahon, G. Nelson (retired) and especially C. Barry (Pacific Hydrographic Branch of the NOS) provided assistance with interpreting smooth sheets, bathymetric sounding files, and descriptive reports. D. Doyle and J. Benson provided valuable datum and GIS advice, respectively. D. Fischman, G. Glover, J.A. Bunn, J. Campagnoli, M. Frydrych, and M. Cole from the National Geophysical Data Center helped with accessing smooth sheets on the NGDC web site.
N/A
N/A
N/A
Data Steward
2015
Person
Zimmermann, Mark
mark.zimmermann@noaa.gov
Distributor
2015
Organization
Alaska Fisheries Science Center
AFSC
afsc.webmaster@noaa.gov
7600 Sand Point Way N.E., Building 4
Seattle
WA
98115
USA
(206) 526-4000
(206) 526-4004
https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center
AKFSC Home Page
Online Resource
0700-1700 Pacific Time
Metadata Contact
2014-09-10
Person
Zimmermann, Mark
mark.zimmermann@noaa.gov
Originator
2014-09-10
Person
Zimmermann, Mark
mark.zimmermann@noaa.gov
Point of Contact
2015
Person
Zimmermann, Mark
mark.zimmermann@noaa.gov
observed
-154.3
-148.9
61.6
58.8
The 20,540 km2 of Cook Inlet, including Kamishak Bay, Kachemak Bay, Knik Arm and Turnagain Arm.
Range
1910
2009
Unclassified
unknown
These data are not to be used for navigation.
These data are not to be used for navigation. As more bathymetry data becomes available, and as more time allows, additional bathymetry drafts will be completed. Our slow method of data editing and compilation, which relied on comparing the digitized soundings to the smooth sheets in a GIS, was vindicated by the discovery and elimination of numerous errors, such as incorrect, misplaced and missing soundings. Properly accounting for the horizontal shift from the original datum to NAD 1983 HARN was the most important part of our error-checking. We consider this smooth sheet bathymetry, feature, shoreline and sediment compilation a fairly complete first draft. This project was small enough, and we had enough time, to work on all four of these interrelated smooth sheet elements, unlike our Aleutian Islands compilation where our efforts were limited to smooth sheet bathymetry and sediments. Additionally we were able to supersede some areas with more modern and detailed multibeam data, something we could not do in the Aleutians. Due to the uncharacteristically thorough and modern coverage of these smooth sheets, we felt confident in producing a 50 m resolution grid for Cook Inlet, offering four times as much detail as our 100 m Aleutians grid.
These data are not to be used for navigation.
http://www.afsc.noaa.gov/RACE/groundfish/bathymetry/Cook_bathymetry_grid.zip
https://www.ncei.noaa.gov
http://www.afsc.noaa.gov/RACE/groundfish/bathymetry/Cook_bathymetry_grid.zip
Online Resource
ZIP
Microsoft Windows 7 Version 6.1 (Build 7600) ; ESRI ArcGIS 10.0.5.4400
Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum.
not applicable
Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum.
See also Data Use Constraints
No
Unknown
No
No
Yes
Unknown
NCEI-MD
unknown
IT Security and Contingency Plan for the system establishes procedures and applies to the functions, operations, and resources necessary to recover and restore data as hosted in the Western Regional Support Center in Seattle, Washington, following a disruption.
unknown
gov.noaa.nmfs.inport:22166
Nancy Roberson
2014-09-10T12:56:18
SysAdmin InPortAdmin
2024-01-15T12:08:04
2016-05-18
Alaska Fisheries Science Center
AFSC
7600 Sand Point Way N.E., Building 4
Seattle
WA
98115
USA
http://www.afsc.noaa.gov
0700-1700 Pacific Time
1001
Public
No
2016-05-18
1 Year
2017-05-18
Raster
Grid Cell
6240
5777
Albers Conical Equal Area
55.0
65.0
-154.0
50.0
0.0
0.0
coordinate pair
0.0000000030536018158500163
0.0000000030536018158500163
meters
D North American 1983
GRS 1980
6378137.0
298.257222101
Mean lower low water
0.3
meters
Explicit depth coordinate included with horizontal coordinates