Determination of distance and location using instruments receiving signals from the Global Positioning System, a system of satellites for identifying earth locations.
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.
Field Office involved in operating GPS stations, data recording, and supplying of earthquake data. Links to GPS data analysis, photos, and technical information.
Results of ground-surface monitoring and borehole water table measurements document subsidence of the land surface correlative with changes in the ground water.
Online report for an interactive workshop Impact of Climate Change and Land Use in the Southwestern United States. Discusses land subsidence due to increased ground water pumping in the Southwest and the damage caused by subsidence.
We combine long-term records from aerial photographs, detailed mapping using survey-grade GPS, and ground-based lidar with meteorological monitoring. Sand dune migration rates are currently about 35 meters per year.
Report on the Sirenia Project use of a radio tracking study to determine manatee movement patterns and habitat to develop ecological models to understand and predict the effects of hydrologic restoration on manatees in Southwest Florida.
Explanation of uplift in the land surface of the northern part of the Yellowstone caldera (12cm, about ~5 inches) that occurred between 1997 and 2003, including the scientific methods by which it was detected and analyzed.
Overview of volcano hazards in California with links to monitoring data including earthquakes and deformations, long-term outlook, volcano hazards in the area, USGS response plan, image gallery, monitoring and topical studies, publications and references.