Articles
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 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.
Filter Total Items: 77863
Hydrothermal alteration can result in pore pressurization and volcano instability Hydrothermal alteration can result in pore pressurization and volcano instability
The collapse of a volcanic flank can be destructive and deadly. Hydrothermal alteration is common to volcanoes worldwide and is thought to promote volcano instability by decreasing rock strength. However, some laboratory studies have shown that not all alteration reduces rock strength. Our new laboratory data for altered rhyodacites from Chaos Crags (Lassen volcanic center, California...
Authors
Michael J. Heap, Tobias Baumann, H. Albert Gilg, Stephan Kolzenburg, Amy Ryan, Marlene C. Villeneuve, James K. Russell, Lori A. Kennedy, Marina Rosas-Carbajal, Michael A. Clynne
Cyprosulfamide: Analysis of the herbicide safener and two of its degradates in surface water and groundwater from the Midwestern United States Cyprosulfamide: Analysis of the herbicide safener and two of its degradates in surface water and groundwater from the Midwestern United States
Herbicide safeners are commonly included in herbicide formulations to selectively protect crops from herbicide toxicity but are poorly understood in terms of their environmental occurrence and fate. This study established an analytical method for a newer safener, cyprosulfamide, and two of its degradates, cyprosulfamide desmethyl and N-cyclopropyl-4-sulfamoylbenzamide, in water via solid...
Authors
Monica E McFadden, Michelle L. Hladik
Conservation implications of spatiotemporal variation in the terrestrial ecology of Western spadefoots Conservation implications of spatiotemporal variation in the terrestrial ecology of Western spadefoots
Conservation of species reliant on ephemeral resources can be especially challenging in the face of a changing climate. Western spadefoots (Spea hammondii) are small burrowing anurans that breed in ephemeral pools, but adults spend the majority of their lives underground in adjacent terrestrial habitat. Western spadefoots are of conservation concern throughout their range because of...
Authors
Brian J. Halstead, Katherine L. Baumberger, Adam R. Backlin, Patrick M. Kleeman, Monique Nicole Wong, Elizabeth Gallegos, Jonathan P. Rose, Robert N. Fisher
Miocene neritic benthic foraminiferal community dynamics, Calvert Cliffs, Maryland, USA: Species pool, patterns and processes Miocene neritic benthic foraminiferal community dynamics, Calvert Cliffs, Maryland, USA: Species pool, patterns and processes
The presence/absence and abundance of benthic foraminifera in successive discrete beds (Shattuck “zones”) of the Miocene Calvert and Choptank formations, exposed at the Calvert Cliffs, Maryland, USA, allows for investigation of community dynamics over space and time. The stratigraphic distribution of benthic foraminifera is documented and interpreted in the context of sea-level change...
Authors
Stephen J. Culver, Seth R Sutton, David J. Mallinson, Martin A Buzas, Marci M. Robinson, Harry J. Dowsett
Spatial and temporal variation in length-weight relationships of age-0 Scaphirhynchus sturgeon in the lower Missouri River Spatial and temporal variation in length-weight relationships of age-0 Scaphirhynchus sturgeon in the lower Missouri River
Length-weight relationships can be useful tools for assessing fish condition. We developed these equations (W = aLb) for wild-caught age-0 (4.1–12.0 cm) Scaphirhynchus sturgeon from eight reaches spanning over 750 river km of the lower Missouri River from 2014 to 2017. We used nonlinear modeling to estimate the constant (a) and exponent (b) of the LW equation for each reach to assess...
Authors
A. Gonzalez, James M. Long, N. J. C. Gosch, A. P. Civiello, T.R. Gemeinhardt, J. R. Hall
Incorporation of non-native species in the diets of cisco (Coregonus artedi) from eastern Lake Ontario Incorporation of non-native species in the diets of cisco (Coregonus artedi) from eastern Lake Ontario
Cisco Coregonus artedi was once an important native fish in Lake Ontario; however, after multiple population crashes, the cisco stock has yet to recover to historic abundances. Rehabilitation of cisco in Lake Ontario is a fish community management objective, but the extent to which recent non-native species and pelagic food web changes have influenced cisco is not well understood. We...
Authors
Alexander Gatch, Brian Weidel, Dimitry Gorsky, Brian O’Malley, Michael Connerton, Jeremy Holden, Kristen T. Holeck, J.A. Goertzke, Curtis T. Karboski
Inter-source interferometry of seismic body waves: Required conditions and examples Inter-source interferometry of seismic body waves: Required conditions and examples
Seismic interferometry is widely applied to retrieve wavefields propagating between receivers. Another version of seismic interferometry, called inter-source interferometry, uses the principles of seismic reciprocity and expands interferometric applications to retrieve waves that propagate between two seismic sources. Previous studies of inter-source interferometry usually involve...
Authors
P. Saengduean, Morgan P. Moschetti, R. Snieder
Species-specific demographic and behavioral responses to food availability during migratory stopover Species-specific demographic and behavioral responses to food availability during migratory stopover
Understanding the effects of migratory stopover site conditions on both demographic rates and migratory behaviors is critical for interpreting changes in passage population sizes at stopover sites and predicting responses to future changes and conservation actions. We used a Bayesian formulation of the open robust design model to analyze mark-resight observations of three migratory...
Authors
A. M. Tucker, Conor P. McGowan, James E. Lyons, A. Derose-Wilson, N.A. Clark
Model estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA Model estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA
We present a regression model for estimating mean August baseflow per square kilometer of drainage area to help resource managers assess relative amounts of baseflow in Maine streams with Atlantic Salmon habitat. The model was derived from mean August baseflows computed at 31 USGS streamflow gages in Maine. We use an ordinary least squares regression model to estimate mean August...
Authors
Pamela J. Lombard, Robert W. Dudley, Matthias J. Collins, Rory Saunders, Ernie Atkinson
Experimental evaluation of spatial capture–recapture study design Experimental evaluation of spatial capture–recapture study design
A principal challenge impeding strong inference in analyses of wild populations is the lack of robust and long-term data sets. Recent advancements in analytical tools used in wildlife science may increase our ability to integrate smaller data sets and enhance the statistical power of population estimates. One such advancement, the development of spatial capture–recapture (SCR) methods...
Authors
Jillian Elizabeth Fleming, Evan H. Campbell Grant, Sean C Sterrett, Chris Sutherland
Multicriteria decisions and portfolio analysis: Land acquisition for biological and social objectives Multicriteria decisions and portfolio analysis: Land acquisition for biological and social objectives
Resource allocation for land acquisition is a common multi-objective problem that involves complex trade-offs. The National Wildlife Refuge System (NWRS) of the U.S. Fish and Wildlife Service currently uses the Targeted Resource Acquisition Comparison Tool (TRACT) to allocate funds from the Migratory Bird Conservation Fund (MBCF; established through the Migratory Bird Hunting and...
Authors
Anastasia Ihorvina Krainyk, James E. Lyons, Mindy B. Rice, Kenneth A. Fowler, Gregory J. Soulliere, Michael G. Brasher, Dale D. Humburg, John M. Coluccy
The Chesapeake Bay program modeling system: Overview and recommendations for future development The Chesapeake Bay program modeling system: Overview and recommendations for future development
The Chesapeake Bay is the largest, most productive, and most biologically diverse estuary in the continental United States providing crucial habitat and natural resources for culturally and economically important species. Pressures from human population growth and associated development and agricultural intensification have led to excessive nutrient and sediment inputs entering the Bay...
Authors
Raleigh Hood, Gary W. Shenk, Rachel L Dixon, Sean M. C. Smith, William P. Ball, Jesse Bash, R. Batiuk, Kathy Boomer, Damian C Brady, Carl Cerco, Peter Claggett, Kim de Mutsert, Zachary M. Easton, Andrew J Elmore, Marjorie A. M. Friedrichs, Lora A. Harris, Thomas F. Ihde, Iara Lacher, Li Li, Lewis C. Linker, Andrew Miller, Julia Moriarty, Gregory E. Noe, George Onyullo, Kenneth A Rose, Katherine Skalak, Richard Tian, Tamie L Veith, Lisa A. Wainger, Donald E. Weller, Yinglong J. Zhang