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Year Published: 2014

High manganese concentrations in rocks at Gale crater, Mars

The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments....

Lanza, Nina L.; Fischer, Woodward W.; Wiens, Roger C.; Grotzinger, John P.; Ollila, Ann M.; Anderson, Ryan B.; Clark, Benton C.; Gellert, Ralf; Mangold, Nicolas; Maurice, Sylvestre; Le Mouélic, Stéphane; Nachon, Marion; Schmidt, Mariek E.; Berger, Jeffrey; Clegg, Samuel M.; Forni, Olivier; Hardgrove, Craig; Melikechi, Noureddine; Newsom, Horton E.; Sautter, Violaine
Lanza, Nina L., Fischer, Woodward W., Wiens, Roger C., Grotzinger, John, Ollila, Ann M., Cousin, Agnes, Anderson, Ryan B., Clark, Benton C., Gellert, Ralf, Mangold, Nicolas, Maurice, Sylvestre, Le Mouélic, Stéphane, Nachon, Marion, Schmidt, Mariek, Berger, Jeffrey, Clegg, Samuel M., Forni, Olivier, Hardgrove, Craig, Melikechi, Noureddine, Newsom, Horton E., and Sautter, Violaine, 2014, High manganese concentrations in rocks at Gale crater, Mars, Geophysical Research Letters, doi:10.1002/2014GL060329

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Year Published: 2014

Colorado River campsite monitoring, Grand Canyon National Park, Arizona, 1998-2012

River rafting trips and hikers use sandbars along the Colorado River in Marble and Grand Canyons as campsites. The U.S. Geological Survey evaluated the effects of Glen Canyon Dam operations on campsite areas on sandbars along the Colorado River in Grand Canyon National Park. Campsite area was measured annually from 1998 to 2012 at 37 study sites...

Kaplinski, Matt; Hazel, Joe; Parnell, Rod; Hadley, Daniel R.; Grams, Paul
Colorado River campsite monitoring, Grand Canyon National Park, Arizona, 1998-2012; 2014; OFR; 2014-1161; Kaplinski, Matt; Hazel, Joe; Parnell, Rod; Hadley, Daniel R.; Grams, Paul

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Year Published: 2014

Design of a sediment-monitoring gaging network on ephemeral tributaries of the Colorado River in Glen, Marble, and Grand Canyons, Arizona

Management of sediment in rivers downstream from dams requires knowledge of both the sediment supply and downstream sediment transport. In some dam-regulated rivers, the amount of sediment supplied by easily measured major tributaries may overwhelm the amount of sediment supplied by the more difficult to measure lesser tributaries. In this first...

Griffiths, Ronald E.; Topping, David J.; Anderson, Robert S.; Hancock, Gregory S.; Melis, Theodore S.
Design of a sediment-monitoring gaging network on ephemeral tributaries of the Colorado River in Glen, Marble, and Grand Canyons, Arizona; 2014; OFR; 2014-1137; Griffiths, Ronald E.; Topping, David J.; Anderson, Robert S.; Hancock, Gregory S.; Melis, Theodore S.

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Year Published: 2014

High diet overlap between native small-bodied fishes and nonnative fathead minnow in the Colorado River, Grand Canyon, Arizona

River regulation may mediate the interactions among native and nonnative species, potentially favoring nonnative species and contributing to the decline of native populations. We examined food resource use and diet overlap among small-bodied fishes in the Grand Canyon section of the Colorado River as a first step in evaluating potential resource...

Seegert, Sarah E. Zahn; Rosi-Marshall, Emma J.; Baxter, Colden V.; Kennedy, Theodore A.; Hall, Robert O.; Cross, Wyatt F.
High diet overlap between native small-bodied fishes and nonnative fathead minnow in the Colorado River, Grand Canyon, Arizona; 2014; Article; Journal; Transactions of the American Fisheries Society; Seegert, Sarah E. Zahn; Rosi-Marshall, Emma J.; Baxter, Colden V.; Kennedy, Theodore A.; Hall, Robert O., Jr.; Cross, Wyatt F.

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Year Published: 2014

Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico

Chapter 1.—We measured bird abundance and richness along the upper San Pedro River in 2005 and 2006, in order to document how beavers (Castor canadensis) may act as ecosystem engineers after their reintroduction to a desert riparian area in the Southwestern United States. In areas where beavers colonized, we found higher bird abundance and...

Johnson, Glenn E.; van Riper, Charles
Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico; 2014; OFR; 2014-1121; Johnson, Glenn E.; van Riper, Charles, III

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Year Published: 2014

Graptemys gibbonsi Lovich and McCoy -- Pascagoula Map Turtle

DEFINITION. The Pascagoula Map Turtle, Graptemys gibbonsi, is a large riverine species that exhibits pronounced sexual dimorphism, where females attain a maximum carapace length (CL) of 295 mm and males a maximum of 141 mm (Lovich et al. 2009). Mean adult female CL (248 mm) can be well over twice the mean CL of adult males (104 mm; Gibbons and...

Lovich, Jeffrey E.; Ennen, Joshua R.
Lovich, J.E., and Ennen, J.R., 2014, Graptemys gibbonsi Lovich and McCoy Pascagoula Map Turtle: Catalogue of American Amphibians and Reptiles, p. 901.1-901.8, http://www.zenscientist.com/index.php/pdflibrary2/Open-Access-Journals/caar/Graptemys-gibbonsi-2014-(901)1-8/.

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Year Published: 2014

Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification

The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates. The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies...

Fergason, Robin L.; Gaddis, Lisa R.; Rogers, A. D.

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Year Published: 2014

Geologic map of Mars

This global geologic map of Mars, which records the distribution of geologic units and landforms on the planet's surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and...

Tanaka, Kenneth L.; Skinner, James A.; Dohm, James M.; Irwin, Rossman P.; Kolb, Eric J.; Fortezzo, Corey M.; Platz, Thomas; Michael, Gregory G.; Hare, Trent M.
Geologic map of Mars; 2014; SIM; 3292; Tanaka, Kenneth L.; Skinner, James A., Jr.; Dohm, James M.; Irwin, Rossman P., III; Kolb, Eric J.; Fortezzo, Corey M.; Platz, Thomas; Michael, Gregory G.; Hare, Trent M.

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Year Published: 2014

Indirect effects of biocontrol of an invasive riparian plant (Tamarix) alters habitat and reduces herpetofauna abundance

The biological control agent (tamarisk leaf beetle, Diorhabda spp.) is actively being used to defoliate exotic saltcedar or tamarisk (Tamarix spp.) in riparian ecosystems in western USA. The Virgin River in Arizona and Nevada is a system where tamarisk leaf beetle populations are spreading. Saltcedar biocontrol, like other control methods, has the...

Bateman, H.L.; Merritt, D.M.; Glenn, E.P.; Nagler, P.L.
Indirect effects of biocontrol of an invasive riparian plant (Tamarix) alters habitat and reduces herpetofauna abundance; 2014; Article; Journal; Biological Invasions; Bateman, H. L.; Merritt, D. M.; Glenn, E. P.; Nagler, P. L.

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Year Published: 2014

High spatial resolution WorldView-2 imagery for mapping NDVI and its relationship to temporal urban landscape evapotranspiration factors

Evapotranspiration estimation has benefitted from recent advances in remote sensing and GIS techniques particularly in agricultural applications rather than urban environments. This paper explores the relationship between urban vegetation evapotranspiration (ET) and vegetation indices derived from newly-developed high spatial resolution WorldView-...

Nouri, Hamideh; Beecham, Simon; Anderson, Sharolyn; Nagler, Pamela
High spatial resolution WorldView-2 imagery for mapping NDVI and its relationship to temporal urban landscape evapotranspiration factors; 2014; Article; Journal; Remote Sensing; Nouri, Hamideh; Beecham, Simon; Anderson, Sharolyn; Nagler, Pamela

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Year Published: 2014

Ecological consequences of the expansion of N2-fixing plants in cold biomes

Research in warm-climate biomes has shown that invasion by symbiotic dinitrogen (N2)-fixing plants can transform ecosystems in ways analogous to the transformations observed as a consequence of anthropogenic, atmospheric nitrogen (N) deposition: declines in biodiversity, soil acidification, and alterations to carbon and nutrient cycling, including...

Hiltbrunner, Erika; Aerts, Rien; Bühlmann, Tobias; Huss-Danell, Kerstin; Magnusson, Borgthor; Myrold, David D.; Reed, Sasha C.; Sigurdsson, Bjarni D.; Körner, Christian
Ecological consequences of the expansion of N2-fixing plants in cold biomes; 2014; Article; Journal; Oecologia; Hiltbrunner, Erika; Aerts, Rien; Bühlmann, Tobias; Huss-Danell, Kerstin; Magnusson, Borgthor; Myrold, David D.; Reed, Sasha C.; Sigurdsson, Bjarni D.; Körner, Christian

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Year Published: 2014

2010 weather and aeolian sand-transport data from the Colorado River corridor, Grand Canyon, Arizona

Measurements of weather parameters and aeolian sand transport were made in 2010 near selected archeological sites in the Colorado River corridor through Grand Canyon, Arizona. Data collected in 2010 indicate event- and seasonal-scale variations in rainfall, wind, temperature, humidity, and barometric pressure. Differences in weather patterns...

Dealy, Timothy P.; East, Amy E.; Fairley, Helen C.
2010 weather and aeolian sand-transport data from the Colorado River corridor, Grand Canyon, Arizona; 2014; OFR; 2014-1135; Dealy, Timothy P.; East, Amy E.; Fairley, Helen C.

Nine USGS Science Centers are administered by the Pacific Regional office, which is headquartered in Sacramento, California.