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Map Layer Info

Grayscale North America Shaded Relief – 1 Kilometer Resolution

What this map layer shows:

The shape of the land surface of North America, in gray and at a resolution of one kilometer.

Also available is Grayscale United States Shaded Relief - 200 Meter Resolution

opens the U.S. Geological Survey home page
Background Information
Sample map Sample Map
GTOPO30 elevation data constitute a global digital elevation model with elevation values measured approximately 1 kilometer apart. Each grid cell in the model has a value that represents the average height above sea level within that cell. The Grayscale North America Shaded Relief - 1 Kilometer Resolution map layer was developed from GTOPO30 data.

The three-dimensional appearance of this image was achieved by determining a gray tone at each point, calculated from the steepness of the slope combined with illumination as if there were a light source in the northwest. The height is exaggerated ten times. The exaggeration factor applied to elevation data in the calculation of shaded relief is necessary to add depth so that features can be seen clearly, but it can be misleading. For example, shallow stream valleys can look like steep canyons. In general, grayscale shaded relief can make flat-to-moderate landscapes appear more rugged than they really are.

Production of this map layer was part of a collaborative effort led by staff at the U.S. Geological Survey Center for Earth Resources Observation and Science (EROS). This center archives, processes, and distributes remotely sensed data, including elevation data at various scales, and works with agencies and organizations around the world to support studies using remotely sensed data. Small-scale elevation data are used for a wide variety of applications, including landscape visualization, hydrologic modeling, and geologic studies.

The Grayscale North America Shaded Relief - 1 Kilometer Resolution map layer is a shaded-relief image showing the terrain of most of North America. This map layer shows the general nature of the landscape in a visually dramatic way but does not portray elevation values. From the grayscale shaded relief image there is no way to tell how high or low an area is and precise measurements of slope or aspect cannot be made. The original GTOPO30 data must be used for conducting analysis and determining elevation values.

The National Atlas also includes a 200 meter resolution grayscale shaded relief map layer that covers the United States, Puerto Rico, and the U.S. Virgin Islands.


Map Maker Sample
Shaded Relief Land - Gray