Regions

Southwest

Regions L2 Landing Page Tabs

Filter Total Items: 2,184
Publication Thumbnail
Year Published: 2018

Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers...

Voichick, Nicholas; Topping, David; Griffiths, Ronald
Voichick, N., Topping, D.J., and Griffiths, R.E., 2018, Technical note--False low turbidity readings during high suspended-sediment concentrations: Hydrology and Earth System Sciences, v. 22, p. 1767-1773, https://doi.org/10.5194/hess-22-1767-2018.

Publication Thumbnail
Year Published: 2018

Automated remote cameras for monitoring alluvial sandbars on the Colorado River in Grand Canyon, Arizona

Automated camera systems deployed at 43 remote locations along the Colorado River corridor in Grand Canyon National Park, Arizona, are used to document sandbar erosion and deposition that are associated with the operations of Glen Canyon Dam. The camera systems, which can operate independently for a year or more, consist of a digital camera...

Grams, Paul E.; Tusso, Robert B.; Buscombe, Daniel
Grams, P.E., Tusso, R.B., and Buscombe, D., 2018, Automated remote cameras for monitoring alluvial sandbars on the Colorado River in Grand Canyon, Arizona: U.S. Geological Survey Open-File Report 2018–1019, 50 p., https://doi.org/10.3133/ofr20181019.

Publication Thumbnail
Year Published: 2018

Pulsed flows, tributary inputs, and food web structure in a highly regulated river

1.Dams disrupt the river continuum, altering hydrology, biodiversity, and energy flow. Although research indicates that tributary inputs have the potential to dilute these effects, knowledge at the food web level is still scarce.2.Here we examined the riverine food web structure of the Colorado River below Glen Canyon Dam, focusing on organic...

Sabo, John; Caron, Melanie; Doucett, Richard R.; Dibble, Kimberly L.; Ruhi, Albert; Marks, Jane; Hungate, Bruce; Kennedy, Theodore A.
Sabo, J.L., Caron, M., Doucett, R., Dibble, K.L., Ruhi, A., Marks, J.C., Hungate, B.A., and Kennedy, T.A., 2018, in press, Pulsed flows, tributary inputs and food web structure in a highly regulated river: Journal of Applied Ecology, v. (online), http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.13109/full.

Publication Thumbnail
Year Published: 2018

Using interviews and biological sign surveys to infer seasonal use of forested and agricultural portions of a human-dominated landscape by Asian elephants in Nepal

Understanding how wide-ranging animals use landscapes in which human use is highly heterogeneous is important for determining patterns of human–wildlife conflict and designing mitigation strategies. Here, we show how biological sign surveys in forested components of a human-dominated landscape can be combined with human interviews in agricultural...

Lamichhane, Babu Ram; Subedi, Naresh; Pokheral, Chiranjibi Prasad; Dhakal, Maheshwar; Acharya, Krishna Prasad; Pradhan, Narendra Man Babu; Smith, James L. David; Malla, Sabita; Thakuri, Bishnu Singh; Yackulic, Charles B.
Lamichhane, B.R., Subedi, N., Pokheral, C.P., Dhakal, M., Acharya, K.P., Pradhan, N.M.B., Smith, J.L.D., Malla, S., Thakuri, B.S., Yackulic, C.B., 2017, Using interviews and biological sign surveys to infer seasonal use of forested and agricultural portions of a human-dominated landscape by Asian elephants in Nepal: Ethnology Ecology and Evolution, p. 1-17, available online at https://doi.org/10.1080/03949370.2017.1405847.

Publication Thumbnail
Year Published: 2018

Macroecological patterns of sexual size dimorphism in turtles of the world

Sexual size dimorphism (SSD) is a well-documented phenomenon in both plants and animals; however, the ecological and evolutionary mechanisms that drive and maintain SSD patterns across geographic space at regional and global scales are understudied, especially for reptiles. Our goal was to examine geographic variation of turtle SSD and to explore...

Agha, Mickey; Ennen, Joshua R.; Nowakowski, A. Justin; Lovich, Jeffrey E.; Sweat, Sarah C.; Todd, Brian D.
Agha, M., Ennen, J.R., Nowakowski, A.J., Lovich, J.E., Sweat, S.C. and Todd, B.D., 2018, Macroecological patterns of sexual size dimorphism in turtles of the world: Journal of Evolutionary Biology, early view, doi:10.1111/jeb.13223, http://dx.doi.org/doi:10.1111/jeb.13223.

Publication Thumbnail
Year Published: 2018

Exposed subsurface ice sheets in the Martian mid-latitudes

Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle.We investigated eight of these locations and found that they expose deposits of water ice that can be >100 meters thick, extending downward from depths as shallow as 1 to...

Dundas, Colin M.; Bramson, Ali M; Ojha, Lujendra; Wray, James J.; Mellon, Michael T.; Byrne, Shane; McEwen, Alfred S.; Putzig, N. E.; Viola, Donna; Sutton, Sarah; Clark, E.; Holt, J.W.
Dundas, C. M., et al. (2018). Exposed subsurface ice sheets in the Martian mid-latitudes. Science, 359, 199-201, doi:10.1126/science.aao1619.

Publication Thumbnail
Year Published: 2018

Forest floor and mineral soil respiration rates in a northern Minnesota red pine chronosequence

We measured total soil CO2 efflux (RS) and efflux from the forest floor layers (RFF) in red pine (Pinus resinosaAit.) stands of different ages to examine relationships between stand age and belowground C cycling. Soil temperature and RS were often lower in a 31-year-old stand (Y31) than in 9-year-old (Y9), 61-year-old (Y61), or 123-year-...

Powers, Matthew; Kolka, Randall; Bradford, John B.; Palik, Brian J.; Jurgensen, Martin
Powers, M., Kolka, R., Bradford, J., Palik, B., and Jurgensen, M., 2018, Forest floor and mineral soil respiration rates in a northern Minnesota red pine chronosequence: Forests, v. 9, no. 1, http://dx.doi.org/10.3390/f9010016.

Publication Thumbnail
Year Published: 2018

Image simulation and assessment of the colour and spatial capabilities of the Colour and Stereo Surface Imaging System (CaSSIS) on the ExoMars Trace Gas Orbiter

This study aims to assess the spatial and visible/near-infrared (VNIR) colour/spectral capabilities of the 4-band Colour and Stereo Surface Imaging System (CaSSIS) aboard the ExoMars 2016 Trace Grace Orbiter (TGO). The instrument response functions for the CaSSIS imager was used to resample spectral libraries, modelled spectra and to construct...

Tornabene, Livio L.; Seelos, Frank P.; Pommerol, Antoine; Thomas, Nicolas; Caudill, Christy M.; Becerra, Patricio; Bridges, John C.; Byrne, Shane; Cardinale, Marco; Chojnacki, Matthew; Conway, Susan J.; Cremonese, Gabriele; Dundas, Colin M.; El-Maarry, M. R.; Fernando, Jennifer; Hansen, Candice J.; Hansen, Kayle; Harrison, Tanya N.; Henson, Rachel; Marinangeli, Lucia; McEwen, Alfred S.; Pajola, Maurizio; Sutton, Sarah S.; Wray, James J.
Tornabene, L. L., et al., 2018. Image Simulation and Assessment of the Colour and Spatial Capabilities of the Colour and Stereo Surface Imaging System (CaSSIS) on the ExoMars Trace Gas Orbiter. Space Science Reviews, 214, doi:10.1007/s11214-017-0436-7.

Publication Thumbnail
Year Published: 2018

Morphological indicators of a mascon beneath Ceres' largest crater, Kerwan

Gravity data of Ceres returned by the National Aeronautics and Space Administration's Dawn spacecraft is consistent with a lower density crust of variable thickness overlying a higher density mantle. Crustal thickness variations can affect the long‐term, postimpact modification of impact craters on Ceres. Here we show that the unusual morphology...

Bland, Michael T.; Ermakov, Anton; Raymond, Carol A.; Williams, David A.; Bowling, Tim J.; Preusker, F.; Park, Ryan S.; Marchi, Simone; Castillo-Rogez, Julie C.; Fu, R.R.; Russell, Christopher T.
Bland, M. T., Ermakov, A. I., Raymond, C. A., Williams, D. A., Bowling, T. J., Preusker, F., … Russell, C. T. (2018). Morphological indicators of a mascon beneath Ceres’s largest crater, Kerwan. Geophysical Research Letters, 45, 1297–1304. https://doi.org/10.1002/2017GL075526

Publication Thumbnail
Year Published: 2018

Planetary dune workshop expands to include subaqueous processes

Dune-like structures appear in the depths of Earth’s oceans, across its landscapes, and in the extremities of the solar system beyond. Dunes rise up under the thick dense atmosphere of Venus, and they have been found under the almost unimaginably ephemeral atmosphere of a comet.

Titus, Timothy N.; Bryant, Gerald; Rubin, David M.
Titus, T., D. M. Rubin, and G. Bryant (2018), Planetary dune workshop expands to include subaqueous processes, Eos, 99, https://doi.org/10.1029/2018EO092783. Published on 15 February 2018.

Publication Thumbnail
Year Published: 2018

Temperate and tropical forest canopies are already functioning beyond their thermal thresholds for photosynthesis

Tropical tree species have evolved under very narrow temperature ranges compared to temperate forest species. Studies suggest that tropical trees may be more vulnerable to continued warming compared to temperate species, as tropical trees have shown declines in growth and photosynthesis at elevated temperatures. However, regional and global...

Mau, Alida C.; Reed, Sasha C.; Wood, Tana E.; Cavaleri, Molly A.
Mau, A.C., Reed, S.C., Wood, T.E., and Caveleri, M.A., 2018, Temperate and tropical forest canopies are already functioning beyond their thermal thresholds for photosynthesis: Forests, v. 9, no. 1, (article 47), http://dx.doi.org//10.3390/f9010047.

Publication Thumbnail
Year Published: 2018

Infrared heater system for warming tropical forest understory plants and soils

The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for...

Kimball, Bruce A.; Alonso-Rodríguez, Aura M.; Cavaleri, Molly A.; Reed, Sasha C.; González, Grizelle; Wood, Tana E.
Kimball, B.A., Alonso-Rodriguez, A.M., Cavaleri, M.A., Reed, S.C., Gonzalez, G., and Wood, T.E., 2018, Infrared heater system for warming tropical forest understory plants and soils: Ecology and Evolution, online, https://doi.org/10.1002/ece3.3780.

Filter Total Items: 239
Image: American Avocet
July 18, 2010

American Avocet

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Black Skimmer
July 8, 2010

Black Skimmer

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Caspian Tern
June 8, 2010

Caspian Tern

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Forster's Tern Diving
June 8, 2010

Forster's Tern Diving

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Forster's Tern Hovering
June 8, 2010

Forster's Tern Hovering

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: California Brown Pelicans
June 8, 2010

California Brown Pelicans

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: California Brown Pelican
June 8, 2010

California Brown Pelican

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Photograph showing bluff erosion during the 2009-10 El Nino, undermining the Great Hwy guardrail at Ocean Beach, San Francisco.
January 20, 2010

Bluff Erosion From El Nino (2009-2010)

Bluff erosion during the 2009–10 El Niño undermined the Great Highway guardrail at Ocean Beach, San Francisco, California. The shoreline eroded, on average, 55 meters that winter, leading to lane closures on the highway and an emergency $5-million revetment along the base of this bluff.

Photograph of bluff erosion in 2010 undermining the Great Highway at the southern end of Ocean Beach, San Francisco.
January 20, 2010

Bluff Erosion From El Nino 2010

Bluff erosion during the 2009–10 El Niño undermined the Great Highway guardrail at the southern end of Ocean Beach, San Francisco, California. The shoreline eroded, on average, 55 meters that winter, leading to lane closures on the highway and an emergency $5-million revetment along the base of this bluff. Photo taken by Jeff Hansen, USGS, 20 January 2010.

Image: Black Skimmer Nesting Colony
July 28, 2009

Black Skimmer Nesting Colony

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Black Skimmer Nesting Colony
July 12, 2009

Black Skimmer Nesting Colony

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Black Skimmer Nesting Colony
July 12, 2009

Black Skimmer Nesting Colony

Birds found in and around the Salton Sea, California.

Attribution: Southwest

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