We studied shrub communities in the Panamint Mountains of the Mojave Desert to determine whether vegetational changes after disturbance can be characterized as "succession" according to modern successional theory. We found, on a variety of disturbed and undisturbed sites, that the rate of change was a function of the type and age of disturbance.
The response of desert plant assemblages to disturbance was studied in Death Valley National Monument, California. Plant assemblages on debris flows, alluvial terraces, five abandoned townsites, and a pipeline corridor were measured to quantify recovery rates and to develop a model of change in desert vegetation.
The current on-line catalog also lists, for some regions of the U.S., mining events that were located by regional networks prior to August 2013 and that were not originally listed in catalogs produced by the USGS/NEIC.
This database contains information on faults and associated folds in the United States that demonstrate geological evidence of coseismic surface deformation in large earthquakes during the Quaternary (the past 1.6 million years).
The text is available online with links to each figure, and as a downloadable ascii file. Illustrations are available online as screen-viewable GIFs, and as downloadable eps files suitable for printing and editing.
The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps that have been attributed with information about age and lithology.
This report presents a flood-duration flow frequency analysis for selected durations (1 day, 3 day, 7 day, 15 day, and 30 day) at 173 streamgaging stations throughout Arizona and in western New Mexico.