gov.noaa.nmfs.inport:22897
eng
UTF8
dataset
Alaska Fisheries Science Center
7600 Sand Point Way N.E., Building 4
Seattle
WA
98115
USA
http://www.afsc.noaa.gov
WWW:LINK-1.0-http--link
Website
Website for this organization
information
0700-1700 Pacific Time
resourceProvider
Zimmermann, Mark
mark.zimmermann@noaa.gov
pointOfContact
2024-02-29T00:00:00
ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data
ISO 19115-2:2009(E)
AFSC/RACE/GAP/Zimmermann: Central Gulf of Alaska Grid
AFSC/RACE/GAP/Zimmermann: Central Gulf of Alaska Grid
2015
publication
NOAA/NMFS/EDM
22897
https://www.fisheries.noaa.gov/inport/item/22897
WWW:LINK-1.0-http--link
Full Metadata Record
View the complete metadata record on InPort for more information about this dataset.
information
Zimmermann, Mark
mark.zimmermann@noaa.gov
originator
http://www.afsc.noaa.gov/RACE/groundfish/bathymetry/CGOA_bathymetry_grid.zip
WWW:LINK-1.0-http--link
Citation URL
Online Resource
download
mapDigital
We assembled 1.75 million National Ocean Service (NOS) bathymetric soundings from 225 lead-line and single-beam echosounder hydrographic surveys conducted from 1901 to 1999 in the central Gulf of 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 Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. There were several areas where these older surveys were superseded by more recent, higher quality multibeam surveys, mostly from the NOS (n=106). Three of these were unprocessed NOS multibeam surveys in the Sitka area, which we edited and processed into final bathymetric surfaces. We reduced the resolution of these multibeam surveys to 100 m, since some may have sub-meter resolution and many exceed a million soundings, and added them to our bathymetry compilation. We proofed, edited or digitized 96,000 cartographic features (mostly from the smooth sheets, some from the multibeam surveys), such as rocky reefs, kelp beds, rocks and islets, creating the most thorough source of these typically shallow, inshore features. The depth surface and inshore features, available at the Alaska Fisheries Science Center (AFSC: http://www.afsc.noaa.gov), were mostly produced at a map scale of 1:20,000.
The purpose for creating this data set was to provide the best available bathymetry and inshore features of the central Gulf of Alaska for predictive, geospatial modeling of marine resources.
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.
completed
Zimmermann, Mark
mark.zimmermann@noaa.gov
pointOfContact
Zimmermann, Mark
mark.zimmermann@noaa.gov
custodian
notPlanned
Alaska
Cook Inlet
North Pacific Ocean
bathymetry
grid
theme
DOC/NOAA/NMFS/AFSC > Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce
dataCentre
Global Change Master Directory (GCMD) Data Center Keywords
2017-04-24
publication
8.5
Groundfish Assessment Program
project
InPort
otherRestrictions
Cite As: Alaska Fisheries Science Center, [Date of Access]: AFSC/RACE/GAP/Zimmermann: Central Gulf of Alaska Grid [Data Date Range], https://www.fisheries.noaa.gov/inport/item/22897.
NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
otherRestrictions
Access Constraints: These data are not to be used for navigation.
otherRestrictions
Use Constraints: 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 critical to 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 and feature compilation a first draft.
unclassified
NOAA Data Management Plan (DMP)
NOAA/NMFS/EDM
22897
https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/22897.pdf
WWW:LINK-1.0-http--link
NOAA Data Management Plan (DMP)
NOAA Data Management Plan for this record on InPort.
information
crossReference
eng; US
elevation
imageryBaseMapsEarthCover
oceans
Microsoft Windows 7 Version 6.1 (Build 7600) ; ESRI ArcGIS 10.0.5.4400
-154.6
-134.2
53.9
60.7
| Currentness: observed
1901
1999
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, 106 multibeam data sets were subsetted at a resolution of 100 m and substituted for the older, less-detailed smooth sheet data. Third, the bathymetry point data, which included bathymetric soundings, inshore features with depths or elevations, and the reduced-resolution multibeam data, were used to create a Triangulated Irregular Network (TIN). The TIN was converted into a grid (raster with 100 meter square pixels). Finally, the grid was trimmed by the shoreline to cover the spatial extent of the study area.
Alaska Fisheries Science Center
(206) 526-4000
(206) 526-4004
7600 Sand Point Way N.E., Building 4
Seattle
WA
98115
afsc.webmaster@noaa.gov
https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center
WWW:LINK-1.0-http--link
Alaska Fisheries Science Center Website
AKFSC Home Page
information
0700-1700 Pacific Time
distributor
https://www.ncei.noaa.gov
WWW:LINK-1.0-http--link
https://www.ncei.noaa.gov
download
http://www.afsc.noaa.gov/RACE/groundfish/bathymetry/CGOA_bathymetry_grid.zip
WWW:LINK-1.0-http--link
http://www.afsc.noaa.gov/RACE/groundfish/bathymetry/CGOA_bathymetry_grid.zip
download
dataset
Completeness Report
Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum.
Conceptual Consistency
not applicable
unknown
otherRestrictions
Use Constraints: These data are not to be used for navigation.