Description | Spatial | Attributes |
Surface effects maps were produced for 72 of 89 underground detonations conducted at the Frenchman Flat, Rainier Mesa and Aqueduct Mesa, Climax Stock, Shoshone Mountain, Buckboard Mesa, and Dome Mountain testing areas of the Nevada Test Site between August 10, 1957 (Saturn detonation, Area 12) and September 18, 1992 (Hunters Trophy detonation, Area 12). The Other Areas Surface Effects Map Database contains digital reproductions of these original maps. The database is provided in both ArcGIS (v. 8.2) geodatabase format and ArcView (v. 3.2) shapefile format. This database contains sinks, cracks, faults, and other surface effects having a combined (cumulative) length of 136.38 km (84.74 mi). In GIS digital format, the user can view all surface effects maps simultaneously, select and view the surface effects of one or more sites of interest, or view specific surface effects by area or site. Three map layers comprise the database. They are: (1) the surface effects maps layer (oase_n27f), (2) the bar symbols layer (oase_bar_n27f), and (3) the ball symbols layer (oase_ball_n27f). Additionally, an annotation layer, named "Ball_and_Bar_Labels," and a polygon features layer, named "Area12_features_poly_n27f," are contained in the geodatabase version of the database. The annotation layer automatically labels all 295 ball-and-bar symbols shown on these maps. The polygon features layer displays areas of ground disturbances, such as rock spall and disturbed ground caused by the detonations. Shapefile versions of the polygon features layer in Nevada State Plane and Universal Transverse Mercator projections, named "area12_features_poly_n27f.shp" and "area12_features_poly_u83m.shp," are also provided in the archive.
Post-detonation surface effects maps were produced for detonation sites using field and aerial-photo mapping techniques. The fractures produced by the detonations were mapped and reported on in many USGS Technical Letter reports. Features mapped included surface cracks (and fractures), collapse sinks, various types of fault movements, pressure ridges, and reactivated cracks. A final surface effects map, or "crack map" as they were often called, was prepared on stable-base mylar drafting film for use in USGS publications and reports. Ultimately, these maps were stored by the USGS in map files at the Denver Federal Center, Lakewood, Colorado. The digital reproduction and archiving of these maps was implemented as a means to not only store the original crack maps in a more permanent compact disc format, but to also make them accessible for scientific study and management activities.
1: This metadata file pertains to the three primary map layers that make up the database, as well as to all other area-wide and site-specific surface effects maps of the "Other Areas" surface effects group that includes the Frenchman Flat, Rainier Mesa and Aqueduct Mesa, Climax Stock, Shoshone Mountain, Buckboard Mesa, and Dome Mountain testing areas. 2: The three map layers are named as follows: oase_n27f: polyline coverage containing the surface effects map features oase_bar_n27f: polyline coverage containing the bars of the bar-and-ball symbols oase_ball_n27f: point coverage containing the balls of the bar-and-ball symbols 3: The bar-and-ball symbols are used to illustrate vertical displacement on the down-thrown side of faults and vertically displaced cracks. The ball symbols (point coverage) contain an attribute field named OFFSET_CM. This field contains a numerical value that is used to label the fault symbols. The value indicates the amount of vertical offset (in centimeters) that was originally measured for these features.