The digital revolution in geologic mapping

[摘要] Geologic field datacollection, analysis, and map compilation are undergoing a revolution inmethods, largely precipitated by global positioning system (GPS) and geographicinformation system (GIS) equipped mobile computers paired with virtual globevisualizations. Modern, ruggedized personal digital assistants (PDAs) andtablet PCs can record a wide spectrum of geologic data and facilitate iterativegeologic map construction and evaluation on location in the field. Spatialdata, maps, and interpretations can be presented in a variety of formats onvirtual globes, such as Google Earth and NASA World Wind, given only a basicknowledge of scripting languages. As a case study, we present geologic mapsassembled in Google Earth that are based on digital field data. Interactivefeatures of these maps include (1) the ability to zoom, pan, and tilt theterrain and map to any desired viewpoint; (2) selectable, draped polygonsrepresenting the spatial extent of geologic units that can be renderedsemi-transparent, allowing the viewer to examine the underlying terrain; (3)vertical cross sections that emerge from the subsurface in their proper locationand orientation; (4) structural symbols (e.g., strike and dip), positioned atoutcrop locations, that can display associated metadata; and (5) other data,such as digital photos or sketches, as clickable objects in their correct fieldlocations.

[学科分类] 地质学

[关键词] Fire safety;fatal fires;smoke alarms