VISUALIZING AND TEACHING THE GEOLOGY OF THE BOISE AREA USING THE DIGITAL ATLAS OF IDAHO

The economic and environmental history of any area is controlled by geography and geology. Teaching about geographical imperatives is important if students are to understand the limits to growth and development imposed by the natural world.

Hosted by the Idaho Museum of Natural History at Idaho State University, the Digital Atlas of Idaho (http://imnh.isu.edu/digitalatlas/) offers graphic and accessible information on all of Idaho’s Natural History, through visual representation of maps and natural features.

Just one example includes the geology and geography of Ada County, Idaho. Important geologic elements that exert first-order controls on life in the Boise Valley include the late Cretaceous Atlanta lobe of the Idaho batholith, Miocene sandstones and volcanic rocks of the Boise foothills, Neogene to Pleistocene sediment and lava that filled the subsiding western Snake River plain, Pleistocene and Holocene basalt cinder cones, and the 14,500 year Lake Bonneville Flood.

These features result in several geologically-controlled issues of importance to Boise residents. For example, the stagnant air inversions of winter are controlled by the topographic setting; the snow at Bogus Basin occurs due to the Neogene uplift of the Boise front range; the warm waters heating downtown buildings are generated along the Boise Front fault; and the Boise water system is controlled by fluvial sands of the Pleistocene and Pliocene Boise River. Agricultural productivity is high in Bonneville flood slackwater silts and zero on scoured scabland.

Using web-based teaching modules and three-dimensional imagery, fusion techniques (e.g. digital geologic maps, satellite imagery, and digital elevation models) and visualizations in virtual reality markup language (VRML) the Digital Atlas makes this fascinating story come alive for the general public, students, educators, and geoscience community in Idaho and beyond. We are also developing tools that will allow users to manipulate, combine, and interpret image data together with other GIS data layers directly on the web site.