Data Access Form

Dataset Title:	ETOPO1 Global Surface Relief: Bedrock
Institution:	NOAA National Geophysical Data Center (NGDC) Marine Geology and Geophysics (MGG) Division (Dataset ID: etopo1_bedrock)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Make a graph

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Dimensions	Size	Spacing
latitude (degrees_north)	10801	0.01666667 (even)

longitude (degrees_east)	21601	0.01666667 (even)

Grid Variables (which always also download all of the dimension variables)

z (meters)

File type: (more information)

(Documentation / Bypass this form)

(Please be patient. It may take a while to get the data.)

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  latitude {
    String _CoordinateAxisType "Lat";
    Float64 actual_range -90.0, 90.0;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range -180.0, 180.0;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  z {
    Float32 _FillValue NaN;
    Float32 actual_range -10898.0, 8271.0;
    Float64 colorBarMaximum 5270.0;
    Float64 colorBarMinimum -7737.0;
    String ioos_category "Bathymetry";
    String long_name "z";
    String positive "up";
    String units "meters";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "CF-1.4";
    String drawLandMask "under";
    Float64 Easternmost_Easting 180.0;
    Float64 geospatial_lat_max 90.0;
    Float64 geospatial_lat_min -90.0;
    Float64 geospatial_lat_resolution 0.016666666666666666;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 180.0;
    Float64 geospatial_lon_min -180.0;
    Float64 geospatial_lon_resolution 0.016666666666666666;
    String geospatial_lon_units "degrees_east";
    String GMT_version "4.5.1 [64-bit]";
    String history 
"grdreformat ETOPO1_Bed_g_gmt4.grd ETOPO1_Bed_g_gmt4_coards.grd
2024-11-21T16:53:41Z https://www.ngdc.noaa.gov/thredds/dodsC/global/ETOPO1_Bed_g_gmt4.nc
2024-11-21T16:53:41Z https://pae-paha.pacioos.hawaii.edu/erddap/griddap/etopo1_bedrock.das";
    String infoUrl "https://www.ngdc.noaa.gov/mgg/global/global.html";
    String institution "NOAA National Geophysical Data Center (NGDC) Marine Geology and Geophysics (MGG) Division";
    String ISO_Topic_Categories "elevation";
    String license 
"The data may be used and redistributed for free but is not intended
for legal use, since it may contain inaccuracies. Neither the data
Contributor, ERD, NOAA, nor the United States Government, nor any
of their employees or contractors, makes any warranty, express or
implied, including warranties of merchantability and fitness for a
particular purpose, or assumes any legal liability for the accuracy,
completeness, or usefulness, of this information.";
    Int32 node_offset 0;
    Float64 Northernmost_Northing 90.0;
    String sourceUrl "https://www.ngdc.noaa.gov/thredds/dodsC/global/ETOPO1_Bed_g_gmt4.nc";
    Float64 Southernmost_Northing -90.0;
    String summary "ETOPO1 is a 1 arc-minute global relief model of Earth's surface that integrates land topography and ocean bathymetry. It was built from numerous global and regional data sets, and is available in \"Ice Surface\" (top of Antarctic and Greenland ice sheets) and \"Bedrock\" (base of the ice sheets) versions.";
    String title "ETOPO1 Global Surface Relief: Bedrock";
    Float64 Westernmost_Easting -180.0;
  }
}

Using griddap to Request Data and Graphs from Gridded Datasets

griddap lets you request a data subset, graph, or map from a gridded dataset (for example, sea surface temperature data from a satellite), via a specially formed URL. griddap uses the OPeNDAP (external link)

Data Access Protocol (DAP) (external link)

and its projection constraints (external link)

The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.

(easy) You can get data by using the dataset's Data Access Form. It makes the URL for you.
(easy) You can make a graph or map by using the dataset's Make A Graph form. It makes the URL for you.
(not hard) You can bypass the forms and get the data or make a graph or map by generating the URL by hand or with a computer program or script.

griddap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/griddap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/griddap/jplMURSST41.htmlTable?analysed_sst[(2002-06-01T09:00:00Z)][(-89.99):1000:(89.99)][(-179.99):1000:(180.0)]
Thus, the query is often a data variable name (e.g., analysed_sst), followed by [(start):stride:(stop)] (or a shorter variation of that) for each of the variable's dimensions (for example, [time][latitude][longitude]).

For details, see the griddap Documentation.