Reports
Science Quality and Integrity
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.
Filter Total Items: 84637
Changes in Mauna Kea Dry Forest Structure 2000-2014 Changes in Mauna Kea Dry Forest Structure 2000-2014
Changes in the structure of the subalpine vegetation of Palila Critical Habitat on the southwestern slope of Mauna Kea Volcano, Hawai‘i, were analyzed using 12 metrics of change in māmane (Sophora chrysophylla) and naio (Myoporum sandwicense) trees surveyed on plots in 2000 and 2014. These two dominant species were analyzed separately, and changes in their structure indicated changes in...
Authors
Paul C. Banko, Kevin W. Brinck
Using resistance and resilience concepts to reduce impacts of annual grasses and altered fire regimes on the sagebrush ecosystem and sage-grouse- A strategic multi-scale approach Using resistance and resilience concepts to reduce impacts of annual grasses and altered fire regimes on the sagebrush ecosystem and sage-grouse- A strategic multi-scale approach
This Report provides a strategic approach for conservation of sagebrush ecosystems and Greater Sage- Grouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2) distribution...
Authors
Jeanne C. Chambers, David A. Pyke, Jeremy D. Maestas, Chad S. Boyd, Steve Campbell, Shawn Espinosa, Doug Havlina, Kenneth F. Mayer, Amarina Wuenschel
230Th/U ages Supporting Hanford Site‐Wide Probabilistic Seismic Hazard Analysis 230Th/U ages Supporting Hanford Site‐Wide Probabilistic Seismic Hazard Analysis
This product represents a USGS Administrative Report that discusses samples and methods used to conduct uranium-series isotope analyses and resulting ages and initial 234U/238U activity ratios of pedogenic cements developed in several different surfaces in the Hanford area middle to late Pleistocene. Samples were collected and dated to provide calibration of soil development in surface...
Authors
James B. Paces
2012 volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory 2012 volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest, or suspected unrest at 11 volcanic centers in Alaska during 2012. Of the two verified eruptions, one (Cleveland) was clearly magmatic and the other (Kanaga) was most likely a single phreatic explosion. Two other volcanoes had notable seismic swarms that probably were caused by magmatic...
Authors
Julie A. Herrick, Christina A. Neal, Cheryl E. Cameron, James P. Dixon, Robert G. McGimsey
ShakeAlert—An earthquake early warning system for the United States west coast ShakeAlert—An earthquake early warning system for the United States west coast
Earthquake early warning systems use earthquake science and the technology of monitoring systems to alert devices and people when shaking waves generated by an earthquake are expected to arrive at their location. The seconds to minutes of advance warning can allow people and systems to take actions to protect life and property from destructive shaking. The U.S. Geological Survey (USGS)...
Authors
Erin R. Burkett, Douglas D. Given, Lucile M. Jones
2011 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory 2011 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near three separate volcanic centers in Alaska during 2011. The year was highlighted by the unrest and eruption of Cleveland Volcano in the central Aleutian Islands. AVO annual summaries no longer report on activity at Russian volcanoes.
Authors
Robert G. McGimsey, J. Zebulon Maharrey, Christina A. Neal
Hydraulic assessment of existing and alternative stream crossings providing fish and wildlife passage at seven sites in Massachusetts Hydraulic assessment of existing and alternative stream crossings providing fish and wildlife passage at seven sites in Massachusetts
Seven existing road crossing structures at streams in Massachusetts were evaluated hydraulically and compared to hypothetical alternative structures designed for Aquatic Organism Passage (AOP) using standards developed by the Massachusetts River Continuity Partnership. Hydraulic simulations made for flood flows ranging from 20- to 0.2-percent annual exceedance probability (AEP) indicate...
Authors
Phillip J. Zarriello, Jeffrey R. Barbaro
Geochemical and modal data for igneous rocks associated with epithermal mineral deposits Geochemical and modal data for igneous rocks associated with epithermal mineral deposits
The purposes of this report are to (1) present available geochemical and modal data for igneous rocks associated with epithermal mineral deposits and (2) to make those data widely and readily available for subsequent, more in-depth consideration and interpretation. Epithermal precious and base-metal deposits are commonly associated with subduction-related calc-alkaline to alkaline arc...
Authors
Edward A. du Bray
Manganese: it turns iron into steel (and does so much more) Manganese: it turns iron into steel (and does so much more)
Manganese is a common ferrous metal with atomic weight of 25 and the chemical symbol Mn. It constitutes roughly 0.1 percent of the Earth’s crust, making it the 12th most abundant element. Its early uses were limited largely to pigments and oxidants in chemical processes and experiments, but the significance of manganese to human societies exploded with the development of modern...
Authors
William F. Cannon
Hydroclimate of the Spring Mountains and Sheep Range, Clark County, Nevada Hydroclimate of the Spring Mountains and Sheep Range, Clark County, Nevada
Precipitation, potential evapotranspiration, and actual evapotranspiration often are used to characterize the hydroclimate of a region. Quantification of these parameters in mountainous terrains is difficult because limited access often hampers the collection of representative ground data. To fulfill a need to characterize ecological zones in the Spring Mountains and Sheep Range of...
Authors
Michael T. Moreo, Gabriel B. Senay, Alan L. Flint, Nancy A. Damar, Randell J. Laczniak, James Hurja
Fort Collins Science Center: science accomplishments for fiscal years 2012 and 2013 Fort Collins Science Center: science accomplishments for fiscal years 2012 and 2013
The Fort Collins Science Center (FORT) is a multi-disciplinary research and development center of the U.S. Geological Survey (USGS) located in Fort Collins, Colorado. Organizationally, FORT is within the USGS Southwest Region, although our work extends across the Nation and into several other countries. FORT research focuses on needs of the land- and water-management bureaus within the U...
Authors
Juliette T. Wilson, David B. Hamilton
Estimated water use in Puerto Rico, 2010 Estimated water use in Puerto Rico, 2010
Water-use data were aggregated for the 78 municipios of the Commonwealth of Puerto Rico for 2010. Five major offstream categories were considered: public-supply water withdrawals and deliveries, domestic and industrial self-supplied water use, crop-irrigation water use, and thermoelectric-power freshwater use. One instream water-use category also was compiled: power-generation instream...
Authors
Wanda L. Molina-Rivera