Institution
United States Geological Survey
Government•Reston, Virginia, United States•
About: United States Geological Survey is a government organization based out in Reston, Virginia, United States. It is known for research contribution in the topics: Population & Groundwater. The organization has 17899 authors who have published 51097 publications receiving 2479125 citations. The organization is also known as: USGS & US Geological Survey.
Topics: Population, Groundwater, Volcano, Aquifer, Sediment
Papers published on a yearly basis
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TL;DR: In this article, the second-order rate constants for HO radicals and NOM were determined from batch ozonation studies, showing that the structural nature of NOM varies temporally and spatially in a water source, and both the nature and amount of nOM will influence oxidation rates.
426 citations
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TL;DR: The recognition and analysis of hydrogeomorphological influences on riparian vegetation are complicated by multiple scales of environmental interactions, by the covariance of some environmental variables, and by feedbacks between vegetation and flood regimes as mentioned in this paper.
Abstract: Riparian vegetation is affected by both flood processes and the characteristics of landforms that are shaped by floods. In many instances, species occurrence can be linked directly to specific fluvial landforms. These spatial relationships are largely due to the role of floods in the differential destruction of vegetation, in the determination of substrate characteristics, and in the transport of propagules. Major floods may, depending on the climatic context, allow for the establishment of stands of vegetation, or restart processes of plant community change. Disturbance by floods can also affect biodiversity: species richness in some watersheds is greatest where steep valley floor gradients allow for high-energy floods.
The recognition and analysis of hydrogeomorphological influences on riparian vegetation are complicated by multiple scales of environmental interactions, by the covariance of some environmental variables, and by feedbacks between vegetation and flood regimes. Copyright © 2000 John Wiley & Sons, Ltd.
425 citations
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TL;DR: Analytical analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole, and that observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no enhancement.
Abstract: During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.
425 citations
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TL;DR: In this article, a series of regression analyses indicate that runoff timing responds equally to the observed decadal-scale trends in winter temperature and interannual temperature variations of the same magnitude.
Abstract: Since the late 1940s, snowmelt and runoff have come increasingly early in the water year in many basins in northern and central California. This subtle trend is most pronounced in moderate-altitude basins, which are sensitive to changes in mean winter temperatures. Such basins have broad areas in which winter temperatures are near enough to freezing that small increases result initially in the formation of less snow and eventually in early snowmelt. In moderate-altitude basins of California, a declining fraction of the annual runoff has come in April–June. This decline has been compensated by increased fractions of runoff at other, mostly earlier, times in the water year. Weather stations in central California, including the central Sierra Nevada, have shown trends toward warmer winters since the 1940s. A series of regression analyses indicate that runoff timing responds equally to the observed decadal-scale trends in winter temperature and interannual temperature variations of the same magnitude...
425 citations
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Chengdu University of Technology1, Charles University in Prague2, University of Potsdam3, University of Southern California4, University of Twente5, Cardiff University6, United States Geological Survey7, Hong Kong University of Science and Technology8, University of Waterloo9, China Earthquake Administration10
TL;DR: In this paper, the authors analyze how earthquakes trigger landslides and highlight research gaps, and suggest pathways toward a more complete understanding of the seismic effects on the Earth's surface, highlighting research gaps.
Abstract: Large earthquakes initiate chains of surface processes that last much longer than the brief moments of strong shaking. Most moderate‐ and large‐magnitude earthquakes trigger landslides, ranging from small failures in the soil cover to massive, devastating rock avalanches. Some landslides dam rivers and impound lakes, which can collapse days to centuries later, and flood mountain valleys for hundreds of kilometers downstream. Landslide deposits on slopes can remobilize during heavy rainfall and evolve into debris flows. Cracks and fractures can form and widen on mountain crests and flanks, promoting increased frequency of landslides that lasts for decades. More gradual impacts involve the flushing of excess debris downstream by rivers, which can generate bank erosion and floodplain accretion as well as channel avulsions that affect flooding frequency, settlements, ecosystems, and infrastructure. Ultimately, earthquake sequences and their geomorphic consequences alter mountain landscapes over both human and geologic time scales. Two recent events have attracted intense research into earthquake‐induced landslides and their consequences: the magnitude M 7.6 Chi‐Chi, Taiwan earthquake of 1999, and the M 7.9 Wenchuan, China earthquake of 2008. Using data and insights from these and several other earthquakes, we analyze how such events initiate processes that change mountain landscapes, highlight research gaps, and suggest pathways toward a more complete understanding of the seismic effects on the Earth's surface.
424 citations
Authors
Showing all 18026 results
Name | H-index | Papers | Citations |
---|---|---|---|
Derek R. Lovley | 168 | 582 | 95315 |
Steven Williams | 144 | 1375 | 86712 |
Thomas J. Smith | 140 | 1775 | 113919 |
Jillian F. Banfield | 127 | 562 | 60687 |
Kurunthachalam Kannan | 126 | 820 | 59886 |
J. D. Hansen | 122 | 975 | 76198 |
John P. Giesy | 114 | 1162 | 62790 |
David Pollard | 108 | 438 | 39550 |
Alan Cooper | 108 | 746 | 45772 |
Gordon E. Brown | 100 | 454 | 32152 |
Gerald Schubert | 98 | 614 | 34505 |
Peng Li | 95 | 1548 | 45198 |
Vipin Kumar | 95 | 614 | 59034 |
Susan E. Trumbore | 95 | 337 | 34844 |
Alfred S. McEwen | 92 | 624 | 28730 |