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
Papers
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TL;DR: The stability of the soil carbon pool appears sensitive to the depth and duration of thaw, and climatic changes that promote thaw are likely to cause a net efflux of carbon dioxide from the site.
Abstract: We used eddy covariance; gas-exchange chambers; radiocarbon analysis; wood, moss, and soil inventories; and laboratory incubations to measure the carbon balance of a 120-year-old black spruce forest in Manitoba, Canada. The site lost 0.3 ± 0.5 metric ton of carbon per hectare per year (ton C ha−1 year−1) from 1994 to 1997, with a gain of 0.6 ± 0.2 ton C ha−1year−1 in moss and wood offset by a loss of 0.8 ± 0.5 ton C ha−1 year−1 from the soil. The soil remained frozen most of the year, and the decomposition of organic matter in the soil increased 10-fold upon thawing. The stability of the soil carbon pool (∼150 tons C ha−1) appears sensitive to the depth and duration of thaw, and climatic changes that promote thaw are likely to cause a net efflux of carbon dioxide from the site.
792 citations
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TL;DR: This review compiles and evaluates existing scientific information on the use, limitations, and procedural considerations for EROD activity (a catalytic measurement of cytochrome P4501A induction) as a biomarker in fish.
Abstract: This review compiles and evaluates existing scientific information on the use, limitations, and procedural considerations for EROD activity (a catalytic measurement of cytochrome P4501A induction) ...
789 citations
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Boston University1, University of Idaho2, Agricultural Research Service3, Goddard Space Flight Center4, United States Forest Service5, University of Maryland, College Park6, South Dakota State University7, Ames Research Center8, Rochester Institute of Technology9, International Water Management Institute10, United States Geological Survey11, Canadian Forest Service12, Virginia Tech13
TL;DR: Free imagery will enable reconstruction of the history of Earth's surface back to 1972, chronicling both anthropogenic and natural changes during a time when the authors' population doubled and the impacts of climate change became noticeable.
Abstract: ![Figure][1]
Free image.
This Landsat 5 image of the southeastern corner of the Black Sea is part of the general U.S. archive that will be accessible for free under the new USGS policy.
CREDIT: BOSTON UNIVERSITY CENTER FOR REMOTE SENSING
We are entering a new era in the Landsat Program, the oldest and most venerable of our Earth-observing satellite programs. With little fanfare, the U.S. Geological Survey (USGS) has begun providing imagery for free over the Internet. Throughout the history of the Landsat Program, the cost and access to imagery has always limited our ability to study our planet and the way it is changing. Beginning with a pilot program to provide “Web-enabled” access to Landsat 7 images of the United States that were collected between 2003 and this year, the USGS now plans to provide top-quality image products for free upon request for the entire U.S. archive, including over 2 million images back to Landsat 1 (1972) [for details and schedules, see ([1][2])]. The release by NASA and the USGS in January 2008 of a new Landsat Data Distribution Policy ([2][3]) was a key step to this goal. Free imagery will enable reconstruction of the history of Earth's surface back to 1972, chronicling both anthropogenic and natural changes during a time when our population doubled and the impacts of climate change became noticeable.
The Landsat Science Team:
1. 1.[↵][4]USGS Technical Announcement ([http://landsat.usgs.gov/images/squares/USGS\_Landsat\_Imagery_Release.pdf][5]).
2. 2.[↵][6]Landsat Missions ([http://ldcm.usgs.gov/pdf/Landsat\_Data\_Policy.pdf][7]).
[1]: pending:yes
[2]: #ref-1
[3]: #ref-2
[4]: #xref-ref-1-1 "View reference 1. in text"
[5]: http://landsat.usgs.gov/images/squares/USGS_Landsat_Imagery_Release.pdf
[6]: #xref-ref-2-1 "View reference 2. in text"
[7]: http://ldcm.usgs.gov/pdf/Landsat_Data_Policy.pdf
785 citations
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TL;DR: The Qinling orogen preserves a record of late mid-Proterozoic to Cenozoic tectonism in central China as mentioned in this paper, where high pressure metamorphism and ophiolite emplacement assembled the Yangtze craton, including the lower Qinling unit, into Rodinia during the ∼1.0 Ga Grenvillian orogeny.
783 citations
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TL;DR: As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies, including small inner satellites that interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system.
Abstract: As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there is considerable variety in density, albedo, and surface morphology and substantial evidence for endogenic surface modification. Trends in density and crater characteristics are quite unlike those of the Galilean satellites. Small inner satellites, three of which were discovered in Voyager images, interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system. Saturn's broad A, B, and C rings contain hundreds of "ringlets," and in the densest portion of the B ring there are numerous nonaxisymmetric features. The narrow F ring has three components which, in at least one instance, are kinked and crisscrossed. Two rings are observed beyond the F ring, and material is seen between the C ring and the planet.
781 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 |