Marine Data Literacy 2.0

Providing instruction for managing, converting, analyzing and displaying oceanographic station data, marine meteorological data, GIS-compatible marine and coastal data or model simulations, and mapped remote sensing imagery

 

 

 

 

Home > 2. Marine GIS > 2.37 Named Places/Features

2.37 Global Gazetteer of Named Marine Places and Features for Marine GIS:  GeoNET Names Server

  • Title:  Global Gazetteer of Named Marine Places and Features for Marine GIS:  GeoNET Names Server

  • Abstract:  In this exercise you'll learn how to obtain ocean feature names and mappable locations from one of the major global sources.  It does not include USA locations (for purely political reasons), but the search and data retrieval mechanisms are robust and easy.  A separate USA feature site is recommended, if needed.

  • Preliminary Reading

    • N/A

  • Required Software:

  • Other Resources: 

    • NGA GEOnet Names Server (GNS) - Currently holds 5,169 total Undersea Features, associated with 10,206 names.  All US undersea features

    • United States Geological Survey (USGS) Geographic Names Information System (GNIS) - The naming authority for undersea features within the "territorial sea" of the US.  All their actual data are included in the GNS.

    • SHAPEFILE - Wikipedia article; read this to get a big surprise.

  • Author:  Murray Brown and Kim Cimmery

  • Version:  8-6-2015

1.  This exercise for specific undersea features should be paired with 2.9 Global Collection of Boundaries and Named Zones Data for Marine GIS:  VLIZ MarineRegions to find all you need for marine maps.  If you are more interested in on-land boundaries, then also check out 2.8 Adding Administrative Boundaries and Coastline to a Project Map in Saga.  On-land physical features are not well covered in MDL.
2.  Open the NGA GEOnet site and read over it to get a feel for the data being provided.
3.  Click on GNS SEARCH > TEXT BASED PAGE in the left-hand menu.

NOTE:  The author finds this data selection method is more straightforward than the graphic method ("OGC VIEWER PAGE").

4.  Deprecated information about the GNIS.

5.  This is the text-based search engine.  You can search for features by name ("ADM1 NAMES"), or you can enter search criteria in a number of categories

 

6.  There are many FEATURE DESIGNATIONS categories, but we'll only use one, shown in the next panel.
7.  Go to the UNDERSEA features designations, and select both of the SEAMOUNT items.
8.  Go to the SPATIAL SEARCH category and study it to figure out how it works.  This is a good interface, but it works a little bit differently from many others.

If you understand these choices and agree with them, then enter them here.  Every choice is important.

 

9.  Click the SEARCH link in the top left corner of the page, or any of the many SEARCH controls on the page. =\

 

10.  This report automatically appears after the search.  It's probable that if you had selected many other features types very similar to seamounts, then the list could have been larger.  This is something you'll have to explore later on your own.

  • NOTE:  There's a PRINT control just above the table so you can save this result as a file or a document.

11.  Now we want to save the actual data for later use in your own GIS.
12.  Go to the EXPORT FILE FORMAT categories, and select SHAPEFILE.
13.  Go to the EXPORT FIELDS categories, and select the fields you want.  Here the author has simply clicked SELECT ALL.
14.  Now look again the upper left corner of the search page, and click EXPORT.

15.  When you click EXPORT, this new item appears on the form:  EXPORT FILE NAME.  Enter an appropriate long filename, as you see here and click SEARCH DATABASE.

16.  The result is a your file is a zipfile, and you can CLICK on this page to download it.
17.  Save the file in the folder LIBERIA > DATA > BASEMAP > FEATURES with the filename seamounts_liberia_geonames.zip
18.  Find and unzip the file to see these content items.
19.  Now you can work with the files in a GIS.  Run Saga.
20.  Use FILE > SHAPES > LOAD to find and open the SHP file you just named.

Then use ADD TO MAP to visualize it.  Here it's shown with the default settings, just to prove it all works.

21.  If you're interested in the details of the data, here's the data table, provided by RIGHT-CLICKING the shape in Saga and selecting ATTRIBUTES > SHOW.

22.  In the process of adding name labels to the above map, Kim Cimmery -- a noted Saga expert -- discovered that the shapefile we made was in the POINTS shape format, not the usual POINT shape format.  You can see the subtle difference in how Saga lists them in the DATA window, where a related file from a different source is displayed.

There's a link above to a great Wikipedia article that explains the 14 different flavors of the shapefile format.

23.  If you want to use these data points in the usual ways, such as station labeling, then you must:
  • Open the TOOL > SHAPES > POINTS > CONVERT MULTIPOINTS TO POINTS
  • Select the seamounts file

When you click OK, the new file will be loaded into Saga.

24.  Here you can see the new data, listed as a POINT shape and not a POINTS shape.

25.  Now that you have a usable data file, you can use these Saga property settings to cause labels to appear.

26.  When you click APPLY, this is how they appear on the screen.

27.  The new form of the shape, using POINT instead of POINTS should be saved to PRODUCTS > SAGA > VECTORS with the filename seamounts_liberia_geonames_point.zip.