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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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Are the horizontal-to-vertical spectral ratios of earthquakes and microtremors the same? Are the horizontal-to-vertical spectral ratios of earthquakes and microtremors the same?
We consider the similarities and differences between earthquake and microtremor horizontal‐to‐vertical spectral ratios (eHVSR and mHVSR, respectively) using a dataset of 161 sites in southern California. Quantitative comparisons are made in terms of the eHVSR and mHVSR lognormal median curves, as well as the frequencies and amplitudes associated with the fundamental‐ and higher‐mode...
Authors
Joseph Vantassel, Makbule Ilgac, Adda Athanasopoulos Zekkos, Alan Yong, Behzad Hassani, Antony Martin
Agricultural tile drains increase the susceptibility of streams to longer and more intense streamflow droughts Agricultural tile drains increase the susceptibility of streams to longer and more intense streamflow droughts
Streamflow droughts are receiving increased attention worldwide due to their impact on the environment and economy. One region of concern is the Midwestern United States, whose agricultural productivity depends on subsurface pipes known as tile drains to improve trafficability and soil conditions for crop growth. Tile drains accomplish this by rapidly transporting surplus soil moisture...
Authors
Seth Adelsperger, Darren Ficklin, Scott Robeson, Margaret Ann Zimmer, John C. Hammond, Damon M. Hall, J.P. Gannon
GeoAI for science and the science of GeoAI GeoAI for science and the science of GeoAI
This paper reviews trends in GeoAI research and discusses cutting-edge ad- vances in GeoAI and its roles in accelerating environmental and social sciences. It ad- dresses ongoing attempts to improve the predictability of GeoAI models and recent re- search aimed at increasing model explainability and reproducibility to ensure trustworthy geospatial findings. The paper also provides...
Authors
Wenwen Li, Samantha T. Arundel, Song Gao, Michael F. Goodchild, Yingjie Hu, Shaowen Wang, Alexander Zipf
Population characteristics of silver carp from the source of their North American introduction in the Lower Mississippi River Population characteristics of silver carp from the source of their North American introduction in the Lower Mississippi River
Silver carp, Hypophthalmichthys molitrix, escaped into the Lower Mississippi River (LMR) over 50 years ago, established reproductive populations, and spread across much of the Mississippi River Basin. Demographic rates of silver carp are needed to inform decisions on control and management of this invasive species, but have not been published for the LMR. The purpose of this paper is to...
Authors
Kenneth J. Killgore, Jan J. Hoover, William T. Slack, James P. Kirk, Bradley R. Lewis, Steven G. George, Leandro E. Miranda
Chronology and Paleoenvironment of the Tunga Formation, a new lowermost Miocene sequence in the East Pisco Basin of southern Peru Chronology and Paleoenvironment of the Tunga Formation, a new lowermost Miocene sequence in the East Pisco Basin of southern Peru
The East Pisco Basin, occupying the coastal plain of Peru between 13°S and 16°S, is widely known for its extensive Eocene to Quaternary biosiliceous deposits and excellent preservation of fossil marine vertebrates. Biochronologic studies published over the past 35 years record a hiatus of about 13 million years (*32–19 Ma) separating the youngest Paleogene deposits (Otuma Formation) from...
Authors
Thomas J. Devries, John A. Barron, Diana Ochoa, Kristen McDougall
Adaptation and Response in Drylands (ARID): Community insights for scoping a NASA terrestrial ecology field campaign in drylands Adaptation and Response in Drylands (ARID): Community insights for scoping a NASA terrestrial ecology field campaign in drylands
Dryland ecosystems cover 40% of our planet's land surface, support billions of people, and are responding rapidly to climate and land use change. These expansive systems also dominate core aspects of Earth's climate, storing and exchanging vast amounts of water, carbon, and energy with the atmosphere. Despite their indispensable ecosystem services and high vulnerability to change...
Authors
Andrew F. Feldman, Sasha C. Reed, Cibele Amaral, Alicja Babst-Kostecka, Flurin Babst, Joel A. Biederman, Charles Devine, Zheng Fu, Julia K. Green, Jessica Guo, Niall P. Hanan, Raymond F. Kokaly, Marcy Litvak, Natasha MacBean, David Moore, Dennis S. Ojima, Benjamin Poulter, Russell L. Scott, William K. Smith, Robert Swap, Compton J. Tucker, Lixin Wang, Jennifer D. Watts, Konrad Wessels, Fangyue Zhang, Wen Zhang
Two-million-year eruptive history of Laguna del Maule volcanic field Two-million-year eruptive history of Laguna del Maule volcanic field
The Laguna del Maule (LdM) volcanic field, which surrounds the 54-km2 lake of that name, covers ∼500 km2 of mountainous glaciated terrain with Quaternary lavas and tuffs that extend 40 km westward from the Argentine frontier and 30 km north-south from the Río Campanario to Laguna Fea. Complementing recent investigations of postglacial volcanism and the ongoing geophysical unrest around...
Authors
Edward Hildreth, Judith E. Fierstein
Modeling the effects of temperature and limiting nutrients on the competition of an invasive floating plant, Pontederia crassipes, with submersed vegetation in a shallow lake Modeling the effects of temperature and limiting nutrients on the competition of an invasive floating plant, Pontederia crassipes, with submersed vegetation in a shallow lake
The potential for a non-native plant species to invade a new habitat depends on broadscale factors such as climate, local factors such as nutrient availability, and the biotic community of the habitat into which the plant species is introduced. We developed a spatially explicit model to assess the risk of expansion of a floating invasive aquatic plant species (FAV), the water hyacinth...
Authors
Linhao Xu, Don DeAngelis
Biogeochemical and community ecology responses to the wetting of non-perennial streams Biogeochemical and community ecology responses to the wetting of non-perennial streams
Transitions between dry and wet hydrologic states are the defining characteristic of non-perennial rivers and streams, which constitute the majority of the global river network. Although past work has focused on stream drying characteristics, there has been less focus on how hydrology, ecology and biogeochemistry respond and interact during stream wetting. Wetting mechanisms are highly...
Authors
Adam N. Price, Margaret Ann Zimmer, Anna J. Bergstrom, Amy J Burgin, Erin C. Seybold, Corey A. Krabbenhoft, Sam Zipper, Michelle H. Busch, Walter K. Dodds, Annika W. Walters, Jane S. Rogosch, Rachel Stubbington, Richard H Walker, James C. Stegen, Thibault Datry, Mathis L. Messager, Julian Olden, Sarah E Godsey, Margaret Shanafield, David E. Lytle, Ryan Burrows, Kendra E. Kaiser, George H. Allen, Meryl C. Mims, Jonathan D. Tonkin, Michael Bogan, John Christopher Hammond, Kate Boersma, Allison Myers-Pigg, Amanda DelVecchia, Daniel C. Allen, Songyan Yu, Adam Ward
Immunotoxic response of bio-based plastic on early life stage zebrafish (Danio rerio): A safe alternative to petroleum-based plastics? Immunotoxic response of bio-based plastic on early life stage zebrafish (Danio rerio): A safe alternative to petroleum-based plastics?
Bio-based plastics are marketed as environmentally friendly alternatives to petroleum-based plastics, although they require specific composting conditions for degradation, which leads to their accumulation in the environment and potential risks to aquatic organisms. We hypothesized that the accumulation of bio-based plastics may induce immunotoxic responses in fish. Our research focused...
Authors
Haodong Cheng, Yao Zou, Bin Lu, Jiazhen Wang, Rongrong Xuan, Jason Tyler Magnuson, Chunmiao Zheng, Wenhui Qiu
qPCR-based phytoplankton abundance and chlorophyll a: A multi-year study in twelve large freshwater rivers across the United States qPCR-based phytoplankton abundance and chlorophyll a: A multi-year study in twelve large freshwater rivers across the United States
Phytoplankton overgrowth, which characterizes the eutrophication or trophic status of surface water bodies, threatens ecosystems and public health. Quantitative polymerase chain reaction (qPCR) is promising for assessing the abundance and community composition of phytoplankton. However, applications of qPCR to indicate eutrophication and trophic status, especially in lotic systems, have...
Authors
Chiqian Zhang, Kyle D. McIntosh, N. Sienkiewicz, Erin A. Stelzer, Jennifer L. Graham, Jingrang Lu
Naturalized species drive functional trait shifts in plant communities Naturalized species drive functional trait shifts in plant communities
Despite decades of research documenting the consequences of naturalized and invasive plant species on ecosystem functions, our understanding of the functional underpinnings of these changes remains rudimentary. This is partially due to ineffective scaling of trait differences between native and naturalized species to whole plant communities. Working with data from over 75,000 plots and...
Authors
Magda Garbowski, Daniel L. McLaughlin, Dana M. Blumenthal, Helen Sofaer, David Barnett, Evelyn M. Beaury, Daniel Buonaiuto, Jeff Corbin, Jeffrey Dukes, Regan Early, Andrea Nebhut, Lais Petri, Montserrat Vila, Ian S. Pearse