Detailed measurements of elevation help to understand the extent and severity of subsidence. Study asks if subsidence indicates the aquifer system is compacting temporarily or permanently, and are the changes human-induced or tectonic.
Use of diatoms in biostratigraphy, coastal and estuarine studies, paleoceanology, paleoliminology, earthquake studies, environmental quality and forensic studies. Includes listing of USGS diatom projects and links to other diatom websites.
Description of what Digital Orthophoto Quadrangles are and how to obtain them plus information on the DOQ program, points of contact, DOQ status graphic, examples of DOQs, and free data viewer software.
Research exploring the mathematical properties of kriging, a widely-used surface interpolation method. The continuity properties of kriging digital terrain models over a wide range of terrain types helps hydrologists assess the usefulness of kriging for D
Revised geologic time scale indicating the ages of the lower bounds of chronostratigraphic and geochronologic units as they are currently known. Modifications to those ages made since the previous time scale was released (2007) are clearly marked.