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Date/Time Thumbnail Dimensions User Comment; current: 20:09, 21 March 2023: 584 × 1,426 (640 KB): Jengod: Uploaded a work by USGS from USGS 7.5-minute image map for Point Arguello, California Point Pedernales ...
From approximately 1947–1992, the USGS produced the 7.5 minute series, with each map covering an area one-quarter of the older 15-minute quad series, which it replaced. [1] A 7.5 minute quadrangle map covers an area of 49 to 70 square miles (130 to 180 km 2). [2]
File:USGS US Topo 7.5-minute map for Grand Rapids West, MI 2014 (cropped).jpg. Add languages. ... Printable version; Page information; Get shortened URL;
DOQs produced by the USGS cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude (the same area covered by a USGS 1:24,000-scale topographic map, also known as a 7.5-minute quadrangle) or 3.75-minutes by 3.75-minutes.
The USGS also utilizes data from The National Map Corps, which consists of volunteers who devote some of their time to provide cartographic information on structures. [4] The National Map is the official replacement for the USGS topographic map program. [5]
7.5-minute 30-minute Created by autocorrelation or manual profiling from aerial photographs May be derived from a wide variety of sources using any of a number of USGS approved techniques and instrumentation Level 2 All series Created from digital line graph (DLG) contours or equivalent, from any USGS map series up to 1:100000 scale
Topographic maps are also commonly called contour maps or topo maps. In the United States, where the primary national series is organized by a strict 7.5-minute grid, they are often called or quads or quadrangles. Topographic maps conventionally show topography, or land contours, by means of contour lines.
[30] [31] In recent years, budget constraints have forced the USGS to rely on donations of time by civilian volunteers in an attempt to update its 7.5-minute topographic map series, and USGS stated outright in 2000 that the program was to be phased out in favor of The National Map [32] (not to be confused with the National Atlas of the United ...