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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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From flowering to foliage: Accelerometers track tree sway to provide high-resolution insights into tree phenology From flowering to foliage: Accelerometers track tree sway to provide high-resolution insights into tree phenology
Trees are bioindicators of global climate change and regional urbanization, but available monitoring tools are ineffective for fine-scale observation of many species. Using six accelerometers mounted on two urban ash trees (Fraxinus americana), we looked at high-frequency tree vibrations, or change in periodicity of tree sway as a proxy for mass changes, to infer seasonal patterns of...
Authors
Deidre M. Jaeger, A. M. C. Looze, M. S. Raleigh, Brian W. Miller, Jonathan M. Friedman, C. A. Wessman
FluOil: A novel tool for modeling the transport of oil-particle aggregates in inland waterways FluOil: A novel tool for modeling the transport of oil-particle aggregates in inland waterways
Spilled oil in inland waterways can aggregate with mineral and organic particles to form oil-particle aggregates (OPAs). OPAs can be transported in suspension or deposited to the bed. Modeling the fate and transport of OPAs can provide useful information for making mitigation decisions. A novel open-source tool, FluOil, is developed to predict where OPAs may deposit and when they arrive...
Authors
Yilan Li, Zhenduo Zhu, David Soong, Hamed Khorasani, Shu Wang, Faith A. Fitzpatrick, Marcelo H. Garcia
Submarine landslide susceptibility mapping in recently deglaciated terrain, Glacier Bay, Alaska Submarine landslide susceptibility mapping in recently deglaciated terrain, Glacier Bay, Alaska
Submarine mass wasting events have damaged underwater structures and propagated waves that have inundated towns and affected human populations in nearby coastal areas. Susceptibility to submarine landslides can be pronounced in degrading cryospheric environments, where existing glaciers can provide high volumes of sediment, while cycles of glaciation and ice-loss can damage and...
Authors
Nikita N. Avdievitch, Jeffrey A. Coe
Nanoscale isotopic evidence resolves origins of giant Carlin-type ore deposits Nanoscale isotopic evidence resolves origins of giant Carlin-type ore deposits
The western North American Great Basin's Carlin-type deposits represent the largest accumulation of gold in the Northern Hemisphere. The controversy over their origins echoes the debate between Neptunists and Plutonists at the birth of modern geology: were the causative processes meteoric or magmatic? Sulfur isotopes have long been considered key to decoding metal cycling in the Earth's...
Authors
Elizabeth A. Holley, Alexandria M Fulton, C Jilly-Rehak, Craig A. Johnson, Michael J. Pribil
Novel insights on aquatic mammal MHC evolution: Evidence from manatee DQB diversity Novel insights on aquatic mammal MHC evolution: Evidence from manatee DQB diversity
The low diversity in marine mammal major histocompatibility complex (MHC) appears to support the hypothesis of reduced pathogen selective pressure in aquatic systems compared to terrestrial environments. However, the lack of characterization of the aquatic and evolutionarily distant Sirenia precludes drawing more generalized conclusions. Therefore, we aimed to characterize the MHC DQB...
Authors
Andre L.A. de, Pamela K.B. Baker, Breanna Breaux, Jairo M. Oliveira, Alex de Macedo Klautau, Kristian Legatzki, Fabia de Oliveira Luna, Fernanda L.N. Attademo, Margaret Hunter, Michael F. Criscitiello, Maria P. Schneider, Leonardo Sena
Effects of imported recharge on fluoride trends in groundwater used for public supply in California Effects of imported recharge on fluoride trends in groundwater used for public supply in California
Fluoride is a naturally occurring element in groundwater that supports bone and dental health at low concentrations but can cause health problems at elevated concentrations in drinking water. This study investigates spatial and temporal trends for fluoride concentrations in untreated groundwater from over 20,000 public supply wells in California. The presence of a significant temporal...
Authors
Jennifer S. Harkness, Bryant C. Jurgens
Mechanisms of forest resilience Mechanisms of forest resilience
Ecosystems are dynamic systems with complex responses to environmental variation. In response to pervasive stressors of changing climate and disturbance regimes, many ecosystems are realigning rapidly across spatial scales, in many cases moving outside of their observed historical range of variation into alternative ecological states. In some cases, these new states are transitory and...
Authors
Donald A. Falk, Phillip J. van Mantgem, Jon Keeley, Rachel M Gregg, Christopher H. Guiterman, Alan J. Tepley, Derek J N Young, Laura A. E. Marshall
Secretive marsh bird habitat relationships at mid-continent spring migration stopover sites Secretive marsh bird habitat relationships at mid-continent spring migration stopover sites
Despite several secretive marsh bird (SMB) species being listed as critically imperiled throughout the mid-continent of North America, limited information on SMB distribution and habitat use within primary migratory corridors results in uncertainty on contributions of wetlands in mid-latitude states toward their annual cycle needs. Our objectives were to quantify temporal patterns of SMB...
Authors
Elisabeth B. Webb, E.B. Hill, K.M. Malone, D. Mengel
Surface rupture on a secondary fault associated with the August 8, 2020, Mw 5.1 Sparta North Carolina Earthquake Surface rupture on a secondary fault associated with the August 8, 2020, Mw 5.1 Sparta North Carolina Earthquake
On August 8, 2020 northwest North Carolina experienced a Mw 5.1 earthquake that caused damage to buildings and roads in the city of Sparta. A regional centroid moment tensor solution shows the earthquake was the result of slip on a reverse fault with a minor strike-slip component. InSAR data, from the Japan Aerospace Exploration Agency’s ALOS2 satellite, reveal a deformation field that...
Authors
Charles Wicks, Jer-Ming Chiu
Remote sensing of visible dye concentrations during a tracer experiment on a large, turbid river Remote sensing of visible dye concentrations during a tracer experiment on a large, turbid river
Understanding dispersion in rivers is critical for numerous applications, such as characterizing larval drift for endangered fish species and responding to spills of hazardous materials. Injecting a visible dye into the river can yield insight on dispersion processes, but conventional field instrumentation yields limited data on variations in dye concentration over time at a few, fixed...
Authors
Carl J. Legleiter, Brandon James Sansom, R. B. Jacobson
Bridging the gap between spatial modeling and management of invasive annual grasses in the imperiled sagebrush biome Bridging the gap between spatial modeling and management of invasive annual grasses in the imperiled sagebrush biome
Invasions of native plant communities by non-native species present major challenges for ecosystem management and conservation. Invasive annual grasses such as cheatgrass, medusahead, and ventenata are pervasive and continue to expand their distributions across imperiled sagebrush-steppe communities of the western United States. These invasive grasses alter native plant communities...
Authors
Bryan C. Tarbox, Nathan D. Van Schmidt, Jessica E. Shyvers, D. Joanne Saher, Julie A. Heinrichs, Cameron L. Aldridge
How lions move at night when they hunt? How lions move at night when they hunt?
Movement patterns of lions (Panthera leo) reveal how they hunt large herbivores in heterogeneous landscapes such as the Kruger National Park in South Africa. Large herbivores are distributed differently on the landscape and therefore have different vulnerabilities as prey for lions. For instance, blue wildebeest (Connochaetes taurinus) occupy small grazing lawns at night but are...
Authors
Sze-Wing Yiu, Norman Owen-Smith, James W. Cain