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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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Applying U-Th disequilbrium for dating siliceous sinters
Continental hydrothermal systems are critical avenues for the crustal transport of heat and mass captured for geothermal energy and mineral exploration. Thus, understanding their temporal evolution and longevity is important for resource characterization. Deposits of microlaminated siliceous sinter, common surface expressions of high temperature reservoirs (> 170 °C), have the potential...
Authors
Lauren Sankovitch, Carolina Munoz-Saez, Adam M. Hudson, Linda V. Godfrey, Jay Michael Thompson
Shortening migration by 4500 km does not affect nesting phenology or increase nest success for black brant (Branta bernicla nigricans) breeding in Arctic and subarctic Alaska
BackgroundSince the 1980s, Pacific Black Brant (Branta bernicla nigricans, hereafter brant) have shifted their winter distribution northward from Mexico to Alaska (approximately 4500 km) with changes in climate. Alongside this shift, the primary breeding population of brant has declined. To understand the population-level implications of the changing migration strategy of brant, it is...
Authors
Toshio Doroff Matsuoka, Vijay P. Patil, Jerry W. Hupp, Alan G. Leach, John Reed, James S. Sedinger, David H. Ward
Structural analysis of brittle-plastic shear zones in the Sangre de Cristo Range, southern Colorado USA: Superposition of Rio Grande rift extension on Laramide contraction
The Sangre de Cristo Range in southern Colorado exposes some of the deepest Cenozoic structural levels in the Rocky Mountain region, including mylonitic shear zones associated with both the Laramide orogeny and Rio Grande rift. We investigated the relation between Laramide contraction and Rio Grande rift extension with detailed geologic mapping, kinematic analysis, and geochronometry in...
Authors
Michael C. Sitar, John S. Singleton, Jeffrey M. Rahl, Jonathan Caine, Jacob King, Andrew R C Kylander-Clark, Paul O’Sullivan
Bayesian calibration of the 40K decay scheme with implications for 40K-based geochronology
The K/Ar and 40Ar/39Ar geochronometers are based on the naturally occurring radionuclide 40K. Their precision and accuracy are limited by uncertainties on the 40K decay constants and, in the case of the 40Ar/39Ar geochronometer, the isotopic composition of neutron fluence monitors. To address these limitations, we introduce a Bayesian calibration of the 40K decay scheme. We formulate...
Authors
Jack N. Carter, Caroline Hasler, Anthony Fuentes, Andrew Tholt, Leah E. Morgan, Paul R. Renne
An enhanced national-scale urban tree canopy cover dataset for the United States
Moderate-resolution (30-m) national map products have limited capacity to represent fine-scale, heterogeneous urban forms and processes, yet improvements from incorporating higher resolution predictor data remain rare. In this study, we applied random forest models to high-resolution land cover data for 71 U.S. urban areas, moderate-resolution National Land Cover Database (NLCD) Tree...
Authors
Lucila Marie Corro, Kenneth J. Bagstad, Mehdi Heris, Peter Christian Ibsen, Karen Schleeweis, James E. Diffendorfer, Austin Troy, Kevin Megown, Jarlath P.M. O'Neil-Dunne
New paleomagnetic constraints on the eruption timing, stratigraphy, and post-emplacement deformation of the Picture Gorge Basalt within the Columbia River Basalt Group
The Picture Gorge Basalt (PGB) is part of the Miocene Columbia River Basalt Group (CRBG). The PGB, which outcrops in eastern Oregon, is considered coincident in time with the voluminous Grande Ronde Basalt. New radiometric ages have expanded the age‐range of the PGB, suggesting it began erupting prior to the Steens Basalt to its south and continued until after cessation of the Grande...
Authors
Anthony Francis Pivarunas, Margaret Susan Avery, Jonathan T. Hagstrum, Scott E.K. Bennett, Andrew T. Calvert
Unlocking ecological insights from sub-seasonal visible-to-shortwave infrared imaging spectroscopy: The SHIFT campaign
We stand at the threshold of a transformative era in Earth observation, marked by space-borne visible-to-shortwave infrared (VSWIR) imaging spectrometers that promise consistent global observations of ecosystem function, phenology, and inter- and intra-annual change. However, the full value of repeat spectroscopy, the information embedded within different temporal scales, and the...
Authors
K. Dana Chadwick, Frank W. Davis, Kimberley Miner, Ryan Pavlick, Mark Reynolds, Philip A. Townsend, Philip Brodrick, Christiana Ade, Jean Allen, Leander D. L. Anderegg, Yoseline Angel, Indra Boving, Kristin B. Byrd, Petya Campbell, Luke Carberry, Katherine Cavanaugh, Kyle C. Cavanaugh, Kelly Easterday, Regina Eckert, Michelle M. Gierach, Kaitlin Gold, Erin Hestir, Fred Huemmrich, Maggie Klope, Raymond F. Kokaly, Piper Lovegreen, Kelly Luis, Conor McMahon, Nicholas Nidzieko, Francisco Ochoa, Anna Ongjoco, Elsa Ordway, Madeleine Pascolini-Campbell, Natalie Queally, Dar A. Roberts, Clare Saiki, Fabian D Schneider, Alexey N. Shiklomanov, German Silva, Jordan Snyder, Michele Thornton, Anna Trugman, Nidhi Vinod, Ting Zheng, Dulcinea M. Avouris, Brianna Baker, Latha Baskaran, Tom Bell, Megan Berg, Michael Bernas, Niklas Bohn, Renato Braghiere, Zach Breuer, Andrew J. Brooks, Nolan Burkard, Julia Burmistrova, Kerry-Anne Cawse-Nicholson, John Chapman, Johana Chazaro-Haraksin, Joel Cryer, K.C. Cushman, Kyla M. Dahlin, Phuong Dao, Athena DiBartolo, Michael Eastwood, Clayton D. Elder, Angela Giordani, Kathleen Grant, Robert O. Green, Alexa Hanson, Brendan Heberlein, Mark Helmlinger, Simon Hook, Daniel J. Jensen, Emma Johnson, Marie Johnson, Michael Kiper, Christopher Kibler, Jennifer Y. King, Kyle Kovach, Aaron Kreisberg, Daniel Lacey, Evan Lang, Christine M. Lee, Amanda M Lopez, Brittany Lopez Barreto, Andrew Maguire, Elliott Marsh, Charles E. Miller, Dieu My Nguyen, Cassandra Nickles, Jonathan Ocón, Elijah Papen, Maria Park, Benjamin Poulter, Ann M. Raiho, Porter Reim, Timothy J. Robinson, Fernando Romero Galvan, Ethan Shafron, Brenen R. Skalitzky, Sydney Stroschein, Nicole Chin Taylor, David R. Thompson, Kate Thompson, Cecily Tye, Joelie Van Beek, Cecilia Vanden Heuvel, Jonathan Vellanoweth, Evert Vermeer, Claire Villanueva-Weeks, Kristen Zumdahl, David Schimel
Reconstruction of Holocene and Last Interglacial vegetation dynamics and wildfire activity in Southern Siberia
Wildfires are a rapidly increasing threat to boreal forests. While our understanding of the drivers behind wildfires and their environmental impact is growing, it is mostly limited to the observational period. Here we focus on the boreal forests of southern Siberia and exploit a U–Th-dated stalagmite from Botovskaya Cave, located in the upper Lena region of southern Siberia, to document...
Authors
Jade Margerum, Julia Homann, Stuart Umbo, Gernot Nehrke, Thorsten Hoffmann, Anton Vaks, Aleksandr Kononov, Alexander Osintsev, Alena Maria Giesche, Andrew Mason, Franziska A. Lechleitner, Gideon M. Henderson, Ola Kwiecien, Sebastian F.M. Breitenbach
Specific conductance and water type as a proxy model for salinity and total dissolved solids measurements in the Upper Colorado River Basin
Salinity levels in streams and tributaries of the Colorado River Basin have been a major concern for the United States and Mexico for over 50 years as the water is used by millions of people for domestic and industrial purposes. Recently, the United States Geological Survey expanded stream monitoring networks including the number of sites where continuous (15-min) specific conductance is...
Authors
R. Blaine McCleskey, Charles A. Cravotta, Matthew P. Miller, Tanner William Chapin, Fred D. Tillman, Gabrielle L. Keith
Deterministic physics-based earthquake sequence simulators match empirical ground-motion models and enable extrapolation to data poor regimes: Application to multifault multimechanism ruptures
We use the deterministic earthquake simulator RSQSim to generate complex sequences of ruptures on fault systems used for hazard assessment. We show that the source motions combined with a wave propagation code create surface ground motions that fall within the range of epistemic uncertainties for the Next Generation Attenuation‐West2 set of empirical models. We show the model is well...
Authors
Bruce E. Shaw, Kevin Ross Milner, Christine A. Goulet
Designing sortable guilds for multispecies selective fish passage
The importance of connectivity for freshwater organisms is widely recognised, yet in-stream barriers associated with population declines and increased risk of extinction remain globally ubiquitous. Despite their negative consequences, these barriers can protect aquatic communities by limiting the spread of invasive species, leading to conflicting management goals in some regions...
Authors
David Benoit, Daniel Zielinski, Reid G Swanson, Donald Jackson, Robert L. McLaughlin, Theodore Castro-Santos, R. Andrew Goodwin, Thomas C. Pratt, Andrew M. Muir
Mortality events in Yuma myotis (Myotis yumanensis) due to white-nose syndrome in Washington, USA
The impacts of white-nose syndrome (WNS) on many bat species in eastern North America have been well documented because of the length of time that the causative agent, Pseudogymnoascus destructans (Pd), has been present and the ability to monitor bat hibernacula in that region. However, the disease outcomes for bat species in western North America are less known because of the more...
Authors
Jeffrey M. Lorch, A. Tobin, Alexandria Annelise Argue, Valerie I. Shearn-Bochsler, Brenda M. Berlowski-Zier, Kyle George, Katherine H. Haman, Anne Ballmann