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100-Meter Resolution Color-Sliced Elevation of Alaska

Identification Information

Citation
Title
100-Meter Resolution Color-Sliced Elevation of Alaska
Originator
Geological Survey (U.S.)
Publisher
National Atlas of the United States
Publication Date
2013-03-01
Identifier
http://purl.stanford.edu/zn545gm0023
Geospatial Data Presentation Form
mapDigital
Collection Title
National Atlas of the United States of America, 1997-2014
Other Citation Details
These data were downloaded from the National Atlas website (http://www.nationalatlas.gov/atlasftp.html) in August 2014.
Abstract
This layer is a georeferenced raster image displaying color-sliced elevation data for Alaska at 100-meter resolution, using an Albers Equal-Area Conic projection. Each color tint represents a range of elevation values. There are 32 elevation classes and colors required to map all 50 of the United States, Puerto Rico, and the U.S. Virgin Islands, plus an additional class and color to represent non-U.S. land. The Alaska map layer contains all 33 classes. The color-sliced elevation data were derived from National Elevation Dataset (NED) data and show the terrain of Alaska at a resolution of 100 meters. The NED is a raster product assembled by the U.S. Geological Survey, designed to provide national elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections made in the NED assembly process minimize artifacts, permit edge matching, and fill sliver areas of missing data. This layer is part of the 1997-2014 edition of the National Atlas of the United States.
Purpose
The 100-meter resolution color-sliced elevation data were developed to portray the terrain of the United States at 1:1,000,000 scale. They are intended primarily for visual purposes. The original NED data should be used for conducting analysis and determining the most accurate elevation values. No responsibility is assumed by the National Atlas of the United States in the use of these data.
Supplemental Information
Color-sliced elevation is a classification into 32 steps and colors of the 100-meter Elevation data set that is distributed by the National Atlas of the United States. Characteristics and development of the Elevation data are described in the metadata for that data set. The following table describes the elevation limits of each step, the color index value associated with the step, and the red, green, and blue (RGB) values used to display the step in online National Atlas applications. From, To Color Index Red Green Blue Comments Elevation Elevation ---------------------------------------------------------------------------------------- -100 -1 1 178 178 178 Below sea level 0 0 2 193 224 250 Oceans 1 50 3 66 143 150 51 100 4 82 154 156 101 150 5 95 161 158 151 200 6 109 168 160 201 300 7 123 176 164 301 400 8 136 184 167 401 500 9 149 191 169 501 600 10 161 199 171 601 700 11 178 209 176 701 800 12 191 217 178 801 900 13 207 227 182 901 1000 14 221 235 185 1001 1100 15 234 242 187 1101 1200 16 250 252 189 1201 1300 17 252 249 184 1301 1400 18 245 234 171 1401 1500 19 240 222 158 1501 1600 20 235 211 148 1601 1700 21 227 198 136 1701 1900 22 222 188 124 1901 2100 23 214 176 114 2101 2300 24 209 165 102 2301 2500 25 201 152 91 2501 2700 26 196 143 82 2701 2900 27 189 133 74 2901 3200 28 181 122 63 3201 3700 29 176 113 55 3701 4200 30 168 103 45 4201 5200 31 163 95 39 5201 6200 32 156 85 31 n/a n/a 33 240 235 211 non-U.S. land CMY color equivalents are available on request. The minimum and maximum elevation values listed below come from the National Atlas of the United States 100-meter resolution Elevation map layer. Values were derived from the National Elevation Dataset, but should not be considered authoritative elevations of any specific features. Region Minimum elevation Maximum elevation ------------------------------------------------------------------------ Alaska 12 6167 Hawaii -3 4402 Conterminous U.S. -86 4193 PR and VI -6 1322 Included with the GeoTIFF are a reclass table (.txt), a color ramp file (.clr), a Photoshop color table (.act), an information file (.xml), an auxiliary information file (.aux.xml), an image overview file (.ovr), a value attribute database file (.vat.dbf), a .tfw file (more information included below), and a .prj file (more information included below.) The contents of the associated world file (.tfw) are: 100.0 0.0 0.0 -100.0 -3326950.0 2437950.0 The projection (.prj) file contains the following information: PROJCS["Albers_NAD83_Alaska", GEOGCS["GCS_North_American_1983", DATUM["D_North_American_1983", SPHEROID["GRS_1980",6378137.0,298.257222101]], PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]], PROJECTION["Albers"], PARAMETER["False_Easting",0.0], PARAMETER["False_Northing",0.0], PARAMETER["Central_Meridian",-154.0], PARAMETER["Standard_Parallel_1",55.0], PARAMETER["Standard_Parallel_2",65.0], PARAMETER["Latitude_Of_Origin",50.0], UNIT["Meter",1.0]] Data set extent in meters (Albers Equal-Area Conic projection) North 2438000 West -3327000 East 1654000 South 346000 There are no NULL or NODATA values in the GeoTIFF. Instead, all elevation values in oceans have been set to zero as part of the masking process. Information about National Atlas Web services can be found on the Web Map and Web Feature Services page; see http://nationalatlas.gov/infodocs/webservices.html.
Temporal Extent
Currentness Reference
Source data publication date
Time Instant
2012-12-01T00:00:00
Bounding Box
West
-180
East
180
North
71.954724
South
43.053445
ISO Topic Category
imageryBaseMapsEarthCover
elevation
Place Keyword
Alaska
Place Keyword Thesaurus
geonames
Temporal Keyword
2012
Theme Keyword
Digital elevation models
Topographic maps
Theme Keyword Thesaurus
lcsh
Legal Constraints
Use Limitation
Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Geological Survey in the use of these data.
Use Restrictions
otherRestrictions
Other Restrictions
This item is in the public domain.
Status
completed
Maintenance and Update Frequency
notPlanned
Collection
Collection Title
National Atlas of the United States of America, 1997-2014
URL
http://purl.stanford.edu/cv275yx9215
Publication Date
1998-01-01
Language
eng
Credit
National Atlas of the United States. (2013). 100-Meter Resolution Color-Sliced Elevation of Alaska. National Atlas of the United States. Available at: http://purl.stanford.edu/zn545gm0023.
Point of Contact
Contact
John Hutchinson
Delivery Point
47914 252nd Street
City
Sioux Falls
Administrative Area
South Dakota
Postal Code
57198-0001
Country
US
Email
atlasmail@usgs.gov
Phone
1 605 594 6049

Spatial Reference Information

Reference System Identifier
Code
3338
Code Space
EPSG
Version
8.6.2

Data Quality Information

Lineage
Process Step
Description
The color-sliced Elevation image was derived from NatAtlas AK Elevation 2012 by the following steps: The elevation data were input to the ArcGIS Reclass by ASCII File command and sliced into 32 steps as specified in the text reclass table provided with this data set. See the Supplemental Information in this metadata for a table describing the elevation limits for each step. The 32 classes were assigned RGB color values according to the color ramp (.clr) file provided with this data set. Colors were based on the Brown to Blue Green Diverging, Bright color ramp in ArcGIS. Steps (classes) 1 and 2 are reserved for below-sea-level values and ocean (elevation of 0), respectively. The 32-class color-sliced image was loaded into Photoshop. Using the land/water mask, non-U.S. land areas were set to a value of 33. In order to make elevation tints that would be directly comparable across datasets, the same remapping scheme was applied to data for the conterminous U.S., Alaska, Hawaii, and Puerto Rico and the U.S. Virgin Islands. As a result, not all of the 32 elevation steps are represented in every data set. Alaska has all 32 steps represented, but the conterminous U.S. is missing step 32 (elevations higher than 5,200 meters), Hawaii is missing steps 31 and 32 (elevations higher than 4,200 meters), and the Puerto Rico and the U.S. Virgin Islands data set, with a maximum elevation of 1,322 meters, has no data represented in steps 19 through 32. Ocean areas (step 2) were set to an RGB value of (193,224,250). Non-U.S. areas (step 33) were set to an RGB value of (240,235,211).
Process Date
2013-01-01T00:00:00
Source
Title
100-Meter Resolution Land/Water Mask of Alaska
Publication Date
2013-03-01
Originator
U.S. Geological Survey
Publisher
National Atlas of the United States
Description
Spatial information
Source
Title
100-Meter Resolution Elevation of Alaska
Publication Date
2012-12-01
Originator
U.S. Geological Survey
Publisher
National Atlas of the United States
Description
Spatial and attribute information

Distribution Information

Format Name
GeoTIFF
Distributor
Stanford Geospatial Center
Online Access
http://purl.stanford.edu/zn545gm0023
Protocol
http
Name
elslaki0100a.tif
Function
download

Content Information

Content Type
thematicClassification

Spatial Representation Information

Raster
Number of Dimensions
2
Row Count
20920
Column Count
49810
Cell Geometry Type
area
Corner Points
Point
-3327000.000000 346000.000000
Point
-3327000.000000 2438000.000000
Point
1654000.000000 2438000.000000
Point
1654000.000000 346000.000000
Center Point
-836500.000000 1392000.000000

Metadata Reference Information

Hierarchy Level
dataset
Metadata File Identifier
edu.stanford.purl:zn545gm0023
Parent Identifier
http://purl.stanford.edu/cv275yx9215.mods
Dataset URI
http://purl.stanford.edu/zn545gm0023
Metadata Date Stamp
2015-08-12
Metadata Standard Name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata Standard Version
2007
Character Set
utf8
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