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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 82,000 reports authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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Comparison of three DNA extraction kits to establish maximum yield and quality of coral-associated microbial DNA Comparison of three DNA extraction kits to establish maximum yield and quality of coral-associated microbial DNA
Coral microbiology is an expanding field, yet there is no standard DNA extraction protocol. Although many researchers depend on commercial extraction kits, no specific kit has been optimized for use with coral samples. Both soil and plant DNA extraction kits from MO BIO Laboratories, Inc., have been used by many research groups for this purpose. MO BIO recently replaced their PowerPlant®...
Authors
Erin J. Baker, Christina A. Kellogg
Status and understanding of groundwater quality in the South Coast Interior groundwater basins, 2008: California GAMA Priority Basin Project Status and understanding of groundwater quality in the South Coast Interior groundwater basins, 2008: California GAMA Priority Basin Project
Groundwater quality in the approximately 653-square-mile (1,691-square-kilometer) South Coast Interior Basins (SCI) study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The South Coast Interior Basins study unit contains eight priority groundwater basins grouped into three study areas, Livermore, Gilroy...
Authors
Mary C. Parsons, Justin T. Kulongoski, Kenneth Belitz
Groundwater quality in the South Coast Interior Basins, California Groundwater quality in the South Coast Interior Basins, California
Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality...
Authors
Mary C. Parsons, Kenneth Belitz
Two graphical user interfaces for managing and analyzing MODFLOW groundwater-model scenarios Two graphical user interfaces for managing and analyzing MODFLOW groundwater-model scenarios
Scenario Manager and Scenario Analyzer are graphical user interfaces that facilitate the use of calibrated, MODFLOW-based groundwater models for investigating possible responses to proposed stresses on a groundwater system. Scenario Manager allows a user, starting with a calibrated model, to design and run model scenarios by adding or modifying stresses simulated by the model. Scenario...
Authors
Edward R. Banta
Origins and delineation of saltwater intrusion in the Biscayne aquifer and changes in the distribution of saltwater in Miami-Dade County, Florida Origins and delineation of saltwater intrusion in the Biscayne aquifer and changes in the distribution of saltwater in Miami-Dade County, Florida
Intrusion of saltwater into parts of the shallow karst Biscayne aquifer is a major concern for the 2.5 million residents of Miami-Dade County that rely on this aquifer as their primary drinking water supply. Saltwater intrusion of this aquifer began when the Everglades were drained to provide dry land for urban development and agriculture. The reduction in water levels caused by this...
Authors
Scott T. Prinos, Michael A. Wacker, Kevin J. Cunningham, David V. Fitterman
Technical implementation plan for the ShakeAlert production system: an Earthquake Early Warning system for the West Coast of the United States Technical implementation plan for the ShakeAlert production system: an Earthquake Early Warning system for the West Coast of the United States
Earthquake Early Warning (EEW) systems can provide as much as tens of seconds of warning to people and automated systems before strong shaking arrives. The United States Geological Survey (USGS) and its partners are developing such an EEW system, called ShakeAlert, for the West Coast of the United States. This document describes the technical implementation of that system, which...
Authors
Douglas D. Given, Elizabeth S. Cochran, Thomas Heaton, Egill Hauksson, Richard Allen, Peggy Hellweg, John Vidale, Paul Bodin
A quasi-global precipitation time series for drought monitoring A quasi-global precipitation time series for drought monitoring
Estimating precipitation variations in space and time is an important aspect of drought early warning and environmental monitoring. An evolving drier-than-normal season must be placed in historical context so that the severity of rainfall deficits may quickly be evaluated. To this end, scientists at the U.S. Geological Survey Earth Resources Observation and Science Center, working...
Authors
Chris C. Funk, Pete J. Peterson, Martin F. Landsfeld, Diego H. Pedreros, James P. Verdin, James D. Rowland, Bo E. Romero, Gregory J. Husak, Joel C. Michaelsen, Andrew P. Verdin
Tracking change over time: River flooding Tracking change over time: River flooding
Landsat satellites have been capturing images of Earth from space since 1972. These images provide a long-term record of natural and human-induced changes on the global landscape. Comparing images from multiple years reveals slow and subtle changes as well as rapid and devastating ones. Landsat images are available from the Internet at no charge. Using the free software MultiSpec...
Authors
Water Resources Division U.S. Geological Survey
State-and-transition prototype model of riparian vegetation downstream of Glen Canyon Dam, Arizona State-and-transition prototype model of riparian vegetation downstream of Glen Canyon Dam, Arizona
Facing an altered riparian plant community dominated by nonnative species, resource managers are increasingly interested in understanding how to manage and promote healthy riparian habitats in which native species dominate. For regulated rivers, managing flows is one tool resource managers consider to achieve these goals. Among many factors that can influence riparian community...
Authors
Barbara E. Ralston, Anthony M. Starfield, Ronald S. Black, Robert A. Van Lonkhuyzen
Long-term soil monitoring at U.S. Geological Survey reference watersheds Long-term soil monitoring at U.S. Geological Survey reference watersheds
Monitoring the environment by making repeated measurements through time is essential to evaluate and track the health of ecosystems (fig. 1). Long-term datasets produced by such monitoring are indispensable for evaluating the effectiveness of environmental legislation and for designing mitigation strategies to address environmental changes in an era when human activities are altering the
Authors
Michael R. McHale, Jason Siemion, Gregory B. Lawrence, M. Alisa Mast
Influence of the Kingak Shale ultimate shelf margin on frontal structures of the Brooks Range in the National Petroleum Reserve in Alaska Influence of the Kingak Shale ultimate shelf margin on frontal structures of the Brooks Range in the National Petroleum Reserve in Alaska
The Jurassic–Lower Cretaceous Kingak Shale in the National Petroleum Reserve in Alaska (NPRA) includes several southward-offlapping depositional sequences that culminate in an ultimate shelf margin, which preserves the depositional profile in southern NPRA. The Kingak Shale thins abruptly southward across the ultimate shelf margin and grades into condensed shale, which is intercalated...
Authors
Natalie E. Stier, Christopher D. Connors, David W. Houseknecht
Invasive lionfish use a diversity of habitats in Florida Invasive lionfish use a diversity of habitats in Florida
Two species of lionfish (Pterois volitans and Pterois miles) are the first marine fishes known to invade and establish self-sustaining populations along the eastern seaboard of the United States. First documented off the coast of Florida in 1985, lionfish are now found along the Atlantic coast of the United States as well as in the Caribbean Sea and Gulf of Mexico. Although long-term...
Authors
Pamela J. Schofield, Lad Akins, Denise R. Gregoire-Lucente, Rachel J. Pawlitz