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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.
Browse more than 65,000 articles 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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Modeling scenarios for the management of axis deer in Hawai‘i Modeling scenarios for the management of axis deer in Hawai‘i
Axis deer (Axis axis) are invasive species that threaten native ecosystems and agriculture on Maui Island. To mitigate negative effects, it is necessary to understand current abundance, population trajectory, and how to most effectively reduce the population. Our objectives were to examine the population history of Maui axis deer, estimate observed population growth, and use species...
Authors
Steve C. Hess, Seth Judge
Recent nitrogen storage and accumulation rates in mangrove soils exceed historic rates in the urbanized San Juan Bay Estuary (Puerto Rico, United States) Recent nitrogen storage and accumulation rates in mangrove soils exceed historic rates in the urbanized San Juan Bay Estuary (Puerto Rico, United States)
Tropical mangrove forests have been described as “coastal kidneys,” promoting sediment deposition and filtering contaminants, including excess nutrients. Coastal areas throughout the world are experiencing increased human activities, resulting in altered geomorphology, hydrology, and nutrient inputs. To effectively manage and sustain coastal mangroves, it is important to understand...
Authors
Cathleen Wigand, Autumn Oczkowski, Benjamin Branoff, Meagan J. Eagle, Alana Hanson, Rose M. Martin, Stephen Balogh, Kenneth Miller, Evelyn Huertas, Joseph Loffredo, Elizabeth Watson
New insights on faulting and intrusion processes during the June 2007, East Rift Zone eruption of Kilauea volcano, Hawai'i New insights on faulting and intrusion processes during the June 2007, East Rift Zone eruption of Kilauea volcano, Hawai'i
The East Rift Zone (ERZ) of Kīlauea Volcano, Hawai'i, represents one of the most volcanically active regions in the world. The 2007 Father's Day (FD) dike intrusion, eruption, and accompanying slow-slip event (SSE) has been previously modeled using geodetic data to constrain the geometry of the intrusion and the timing and magnitude of the SSE. Here, we perform inversions of three...
Authors
J. Leeburn, C. Wauthier, Emily K. Montgomery-Brown, J. Gonzalez-Santana
Hazard-consistent seismic losses and collapse capacities for light-frame wood buildings in California and Cascadia Hazard-consistent seismic losses and collapse capacities for light-frame wood buildings in California and Cascadia
We evaluate the seismic performance of modern seismically designed wood light-frame (WLF) buildings, considering regional seismic hazard characteristics that influence ground motion duration and frequency content and, thus, seismic risk. Results show that WLF building response correlates strongly with ground motion spectral shape but weakly with duration. Due to the flatter spectral...
Authors
Robert Edward Chase, Abbie B. Liel, Nico Luco, Zach Bullock
Local variations in broadband sensor installations: Orientations, sensitivities, and noise levels Local variations in broadband sensor installations: Orientations, sensitivities, and noise levels
As seismologists continue to place more stringent demands on data quality, accurately described metadata are becoming increasingly important. In order to better constrain the orientation and sensitivities of seismometers deployed in U.S. Geological Survey networks, the Albuquerque Seismological Laboratory (ASL) has recently begun identifying true north with a fiber optic gyroscope (FOG)...
Authors
Adam T. Ringler, Robert Anthony
Mineral deposit discovery order and three-part quantitative assessments Mineral deposit discovery order and three-part quantitative assessments
Larger oil pools tending to be discovered earlier in an exploration play suggests the same pattern might exist for mineral deposits and could be used in predicting sizes of undiscovered deposits in mineral assessments. The volume of individual petroleum pools is highly correlated with surface projection area of pools in basins. The gradual additions to individual oil pool reserves over...
Authors
Donald A. Singer, Michael L. Zientek
Characterization of the biological, physical, and chemical properties of a toxic thin layer in a temperate marine system Characterization of the biological, physical, and chemical properties of a toxic thin layer in a temperate marine system
The distribution of plankton in the ocean is patchy across a wide range of spatial and temporal scales. One type of oceanographic feature that exemplifies this patchiness is a ‘thin layer’. Thin layers are subsurface aggregations of plankton that range in vertical thickness from centimeters to a few meters, which may extend horizontally for kilometers and persist for days. We undertook a...
Authors
Margaret A McManus, Adam T Greer, Amanda HV Timmerman, Jeff C Sevadjian, C. Brock Woodson, Robert Cowen, Derek A Fong, Stephen G. Monismith, Olivia M. Cheriton
Remotely sensed fine-fuel changes from wildfire and prescribed fire in a semi-arid grassland Remotely sensed fine-fuel changes from wildfire and prescribed fire in a semi-arid grassland
The spread of flammable invasive grasses, woody plant encroachment, and enhanced aridity have interacted in many grasslands globally to increase wildfire activity and risk to valued assets. Annual variation in the abundance and distribution of fine-fuel present challenges to land managers implementing prescribed burns and mitigating wildfire, although methods to produce high-resolution...
Authors
Adam Gerhard Wells, Seth M. Munson, Steven Sesnie, Miguel L. Villarreal
Bottom-up and top-down control on hydrothermal resources in the Great Basin: An example from Gabbs Valley, Nevada Bottom-up and top-down control on hydrothermal resources in the Great Basin: An example from Gabbs Valley, Nevada
The Great Basin in the western United States hosts various hydrothermal systems, including both active geothermal systems and ancient systems preserved as mineral deposits. New magnetotelluric and structural geologic data were collected in the Gabbs Valley area of western Nevada to demonstrate the advantage of imaging the full crustal column below known hydrothermal systems. Three...
Authors
Jared R. Peacock, Drew L. Siler
An evaluation of the timing accuracy of global and regional seismic stations and networks An evaluation of the timing accuracy of global and regional seismic stations and networks
Clock accuracy is a basic parameter of any seismic station and has become increasingly important for seismology as the community seeks to refine structures and dynamic processes of the Earth. In this study, we measure the arrival time differences of moderate repeating earthquakes with magnitude 5.0–5.9 in the time range of 1991–2017 at the same seismic stations by cross‐correlating their...
Authors
Ying Yang, Xiaodong Song, Adam T. Ringler
Strong evidence for two disjunct populations of Black Scoters Melanitta americana in North America Strong evidence for two disjunct populations of Black Scoters Melanitta americana in North America
Black Scoters Melanitta americana were marked with satellite transmitters on Atlantic and Pacific coasts of North America to examine continental-scale population delineation. Scoters marked on the different coasts did not overlap at any stage of the annual cycle, suggesting that birds in the two regions could be monitored and managed as separate populations: 1) an Atlantic population...
Authors
Timothy D. Bowman, Scott G. Gilliland, Jason L Schamber, Paul L. Flint, Daniel Esler, W. Sean Boyd, Daniel H. Rosenberg, Jean-Pierre L. Savard, Matthew Perry, Jason E. Osenkowski
Riverscape approaches in practice: Perspectives and applications Riverscape approaches in practice: Perspectives and applications
Landscape perspectives in riverine ecology have been undertaken increasingly in the last 30 years, leading aquatic ecologists to develop a diverse set of approaches for conceptualizing, mapping and understanding ‘riverscapes’. Spatiotemporally explicit perspectives of rivers and their biota nested within the socio-ecological landscape now provide guiding principles and approaches in...
Authors
Christian E. Torgersen, Celine Le Pichon, Aimee H. Fullerton, Stephen J. Dugdale, Jeffrey J. Duda, Floriane Giovannini, Evelyne Tales, Jerome Belliard, Paulo Branco, Normand E. Bergeron, Mathieu L. Roy, Diego Tonolla, Nicolas Lamouroux, Herve Capra, Colden V. Baxter