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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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A statistical framework for integrating nonparametric proxy distributions into geological reconstructions of relative sea level A statistical framework for integrating nonparametric proxy distributions into geological reconstructions of relative sea level
Robust, proxy-based reconstructions of relative sea-level (RSL) change are critical to distinguishing the processes that drive spatial and temporal sea-level variability. The relationships between individual proxies and RSL can be complex and are often poorly represented by traditional methods that assume Gaussian likelihood distributions. We develop a new statistical framework to...
Authors
Erica L. Ashe, Nicole S. Khan, Lauren T. Toth, Andrea Dutton, Robert E. Kopp
Three Mw ≥ 4.7 earthquakes within the Changning (China) shale gas field ruptured shallow faults intersecting with hydraulic fracturing wells Three Mw ≥ 4.7 earthquakes within the Changning (China) shale gas field ruptured shallow faults intersecting with hydraulic fracturing wells
From 2017 to 2019, three destructive earthquakes (27 January 2017 Mw 4.7, 16 December 2018 Mw 5.2, and 3 January 2019 Mw 4.8) occurred in the Changning shale gas field in the southwest Sichuan Basin, China. Previous seismological studies attributed these events to hydraulic fracturing (HF), but were unable to identify the causative seismogenic faults and their slip behaviors. Here, we...
Authors
Shuai Wang, Guoyan Jiang, Xinglin Lei, Andrew J. Barbour, Xibin Tan, Caijun Xu, Xiwei Xu
Fast rupture of the 2009 Mw 6.9 Canal de Ballenas earthquake in the Gulf of California dynamically triggers seismicity in California Fast rupture of the 2009 Mw 6.9 Canal de Ballenas earthquake in the Gulf of California dynamically triggers seismicity in California
In the Gulf of California, Mexico, the relative motion across the North America-Pacific boundary is accommodated by a series of marine transform faults and spreading centers. About 40 M>6 earthquakes have occurred in the region since 1960. On 3 August 2009, an Mw 6.9 earthquake occurred near Canal de Ballenas in the region. The earthquake was a strike-slip event with a shallow hypocenter...
Authors
Wenyuan Fan, Ryo Okuwaki, Andrew J. Barbour, Yihe Huang, Guoqing Lin, Elizabeth S. Cochran
Experimental evaluation of predator exclosures on nest, chick, and adult survival of piping plovers Experimental evaluation of predator exclosures on nest, chick, and adult survival of piping plovers
Species of conservation concern often receive intensive management to improve vital rates and facilitate recovery. Piping plovers (Charadrius melodus) are federally listed in the United States and concerns over nest depredation have prompted widespread use of plover-permeable predator exclosures placed around nests (0.5–2-m radius). While effectiveness of exclosures for improving nest...
Authors
Michael J. Anteau, Rose J. Swift, Mark H. Sherfy, David N. Koons, Kristen S. Ellis, Terry L. Shaffer, Dustin L. Toy, Megan M. Ring
NWTOPT — A hyperparameter optimization approach for selection of environmental model solver settings NWTOPT — A hyperparameter optimization approach for selection of environmental model solver settings
Hyperparameter optimization approaches were applied to improve performance and accuracy of groundwater flow models. Freely available new software, NWTOPT, is described that uses Tree of Parzen Estimators (TPE) and Random Search algorithms to optimize MODFLOW-NWTs solver settings. We ran 3500 trials on a steady-state and transient model. To quantify the performance of candidate solver...
Authors
Max William Newcomer, Randall J. Hunt
Light and flow regimes regulate the metabolism of rivers Light and flow regimes regulate the metabolism of rivers
Mean annual temperature and mean annual precipitation drive much of the variation in productivity across Earth's terrestrial ecosystems but do not explain variation in gross primary productivity (GPP) or ecosystem respiration (ER) in flowing waters. We document substantial variation in the magnitude and seasonality of GPP and ER across 222 US rivers. In contrast to their terrestrial...
Authors
Emily. S Bernhardt, Philip Savoy, Michael J Vlah, Alison Paige Appling, Lauren E Koenig, Robert O Hall Jr., Maite Arroita, Joanna Blaszczak, Alice M. Carter, Matthew J. Cohen, Judson Harvey, James B. Heffernan, Ashley M. Helton, J.D. Hosen, Lily Kirk, William H. McDowell, Emily H. Stanley, Charles B. Yackulic, Nancy B. Grimm
Smoothed Particle Hydrodynamics simulations of reef surf zone processes driven by plunging irregular waves Smoothed Particle Hydrodynamics simulations of reef surf zone processes driven by plunging irregular waves
As waves interact with the slopes of coral reefs and other steep bathymetry profiles, plunging breaking usually occurs where the free surface overturns and violent water motion is triggered. Resolving these surf zone processes pose significant challenges for conventional mesh-based hydrodynamic models, due to the rapidly-deforming nature of the free surface and associated flows. Yet the...
Authors
Ryan J. Lowe, C. Altomare, Mark L. Buckley, Renan F. da Silva, Jeff E. Hansen, Dirk P. Rijnsdorp, J.M. Dominguez, A.J.C. Crespo
Immunological evidence of variation in exposure and immune response to Bacillus anthracis in herbivores of Kruger and Etosha National Parks Immunological evidence of variation in exposure and immune response to Bacillus anthracis in herbivores of Kruger and Etosha National Parks
Exposure and immunity to generalist pathogens differ among host species and vary across spatial scales. Anthrax, caused by a multi-host bacterial pathogen, Bacillus anthracis, is enzootic in Kruger National Park (KNP), South Africa and Etosha National Park (ENP), Namibia. These parks share many of the same potential host species, yet the main anthrax host in one (greater kudu...
Authors
Sunday O. Ochai, Jan E. Crafford, Ayesha Hassim, Charles Byaruhanga, Yen-Hua Huang, Axel Hartmann, Edgar H. Dekker, O. Louis van Schalkwyk, Pauline L. Kamath, Wendy Christine Turner, Henriette van Heerden
Observation-constrained multicycle dynamic models of the southern San Andreas and the northern San Jacinto Faults: Addressing complexity in paleoearthquake extent and recurrence with realistic 2D fault geometry Observation-constrained multicycle dynamic models of the southern San Andreas and the northern San Jacinto Faults: Addressing complexity in paleoearthquake extent and recurrence with realistic 2D fault geometry
Understanding mechanical conditions that lead to complexity in earthquakes is important to seismic hazard analysis. In this study, we simulate physics-based multicycle dynamic models of the San Andreas fault (Carrizo through San Bernardino sections) and the San Jacinto fault (Claremont and Clark strands). We focus on a complex fault geometry based on the Southern California Earthquake...
Authors
Dunyu Liu, Benchuan Duan, Katherine M. Scharer, Doug Yule
Trends in volcano seismology: 2010 to 2020 and beyond Trends in volcano seismology: 2010 to 2020 and beyond
Volcano seismology has been fundamental to our current understanding of crustal magma migration and eruption. The increasing availability of portable seismic networks with the creative use of seismic sources and ambient noise has led to a better understanding of the volcanic structure of many volcanoes and is producing increasingly detailed images of the volcanic subsurface. The past...
Authors
Weston Thelen, Robin Matoza, Alicia J. Hotovec-Ellis
Parcel-level risk affects wildfire outcomes: Insights from pre-fire rapid assessment data for homes destroyed in 2020 East Troublesome Fire Parcel-level risk affects wildfire outcomes: Insights from pre-fire rapid assessment data for homes destroyed in 2020 East Troublesome Fire
Parcel-level risk (PLR) describes how wildfire risk varies from home to home based on characteristics that relate to likely fire behavior, the susceptibility of homes to fire, and the ability of firefighters to safely access properties. Here, we describe the WiRē Rapid Assessment (RA), a parcel-level rapid wildfire risk assessment tool designed to evaluate PLR with a small set of...
Authors
James R. Meldrum, Christopher M. Barth, Julia B. Goolsby, Schelly K. Olson, Adam C. Gosey, James (Brad) White, Hannah Brenkert-Smith, Patricia A. Champ, Jamie Gomez
Novel genome characteristics contribute to the invasiveness of Phragmites australis (common reed) Novel genome characteristics contribute to the invasiveness of Phragmites australis (common reed)
The rapid invasion of the non-native Phragmites australis (Poaceae, subfamily Arundinoideae) is a major threat to native wetland ecosystems in North America and elsewhere. We describe the first reference genome for P. australis and compare invasive (ssp. australis) and native (ssp. americanus) genotypes collected from replicated populations across the Laurentian Great Lakes to deduce...
Authors
Dong-Ha Oh, Kurt P. Kowalski, Quynh Quach, Chathura Wijesinghege, Philippa Tanford, Maheshi Dassanayake, Keith Clay