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Southwest

Regions L2 Landing Page Tabs

Filter Total Items: 2,153
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Year Published: 2017

Geomorphic process from topographic form: automating the interpretation of repeat survey data in river valleys

The ability to quantify the processes driving geomorphic change in river valley margins is vital to geomorphologists seeking to understand the relative role of transport mechanisms (e.g. fluvial, aeolian, and hillslope processes) in landscape dynamics. High-resolution, repeat topographic data are becoming readily available to geomorphologists. By...

Kasprak, Alan; Caster, Joshua J.; Bangen, Sara G.; Sankey, Joel B.
Kasprak, A., Caster, J., Bangen, S.G., and Sankey, J.B., 2017, Geomorphic process from topographic form:automating the interpretation of repeat survey data in river valleys: Earth Surface Processes and Landforms, online, DOI: 10.1002/esp.4143

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Year Published: 2017

Terrestrial subaqueous seafloor dunes: Possible analogs for Venus

Dunes on Venus, first discovered with Magellan Synthetic Aperture Radar (SAR) in the early 1990s, have fueled discussions about the viability of Venusian dunes and aeolian grain transport. Confined to two locations on Venus, the existence of the interpreted dunes provides evidence that there could be transportable material being mobilized into...

Neakrase, Lynn D.V.; Klose, Martina; Titus, Timothy N.

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Year Published: 2017

Density-dependent vulnerability of forest ecosystems to drought

1. Climate models predict increasing drought intensity and frequency for many regions, which may have negative consequences for tree recruitment, growth and mortality, as well as forest ecosystem services. Furthermore, practical strategies for minimizing vulnerability to drought are limited. Tree population density, a metric of tree abundance in a...

Bottero, Alessandra; D'Amato, Anthony W.; Palik, Brian J.; Bradford, John B.; Fraver, Shawn; Battaglia, Mike A.; Asherin, Lance A.
Bottero, A., D’Amato, A.W., Palik, B.J., Bradford, J.B., Fraver, S., Battaglia, M.A., and Asherin, L.A., 2017, Density-dependent vulnerability of forest ecosystems to drought, Journal of Applied Ecology, v. (online), http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12847/full and http://dx.doi.org/10.1111/1365-2664.12847.

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Year Published: 2017

Channel mapping river miles 29–62 of the Colorado River in Grand Canyon National Park, Arizona, May 2009

Bathymetric, topographic, and grain-size data were collected in May 2009 along a 33-mi reach of the Colorado River in Grand Canyon National Park, Arizona. The study reach is located from river miles 29 to 62 at the confluence of the Colorado and Little Colorado Rivers. Channel bathymetry was mapped using multibeam and singlebeam echosounders,...

Kaplinski, Matt; Hazel, Joseph E.; Grams, Paul E.; Kohl, Keith; Buscombe, Daniel D.; Tusso, Robert B.
Kaplinski, M., Hazel, J.E., Jr., Grams, P.E., Kohl, Keith, Buscombe, D.D., and Tusso, R.B., 2017, Channel mapping river miles 29–62 of the Colorado River in Grand Canyon National Park, Arizona, May 2009: U.S. Geological Survey Open-File Report 2017–1030, 35 p., https://doi.org/10.3133/ofr20171030.

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Year Published: 2017

Changes in community-level riparian plant traits over inundation gradients, Colorado River, Grand Canyon

Comparisons of community-level functional traits across environmental gradients have potential for identifying links among plant characteristics, adaptations to stress and disturbance, and community assembly. We investigated community-level variation in specific leaf area (SLA), plant mature height, seed mass, stem specific gravity (SSG), relative...

McCoy-Sulentic, Miles; Kolb, Thomas; Merritt, David; Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel; Shafroth, Patrick B.
McCoy-Sulentic, M.E., Kolb, T.E., Merritt, D.M., Palmquist, E., Ralston, B.E., Sarr, D.A., and Shafroth, P.B., 2017, Changes in Community-Level Riparian Plant Traits over Inundation Gradients, Colorado River, Grand Canyon: Wetlands, online, doi:10.1007/s13157-017-0895-3.

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Year Published: 2017

The vanishing cryovolcanoes of Ceres

Ahuna Mons is a 4 km tall mountain on Ceres interpreted as a geologically young cryovolcanic dome. Other possible cryovolcanic features are more ambiguous, implying that cryovolcanism is only a recent phenomenon or that other cryovolcanic structures have been modified beyond easy identification. We test the hypothesis that Cerean cryovolcanic...

Sori, Michael M.; Byrne, Shane; Bland, Michael T.; Bramson, Ali; Ermakov, Anton; Hamilton, Christoper; Otto, Katharina; Ruesch, Ottaviano; Russell, Christopher

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Year Published: 2017

Functional traits and ecological affinities of riparian plants along the Colorado River in Grand Canyon

Trait-based approaches to vegetation analyses are becoming more prevalent in studies of riparian vegetation dynamics, including responses to flow regulation, groundwater pumping, and climate change. These analyses require species trait data compiled from the literature and floras or original field measurements. Gathering such data makes trait-...

Palmquist, Emily C.; Ralston, Barbara E.; Sarr. Daniel; Merritt, David; Shafroth, Patrick B; Scott, Julian
Palmquist, E.C., Ralston, B.R., Sarr, D., Merritt D.M., Shafroth, P.B., and Scott, J.A., 2017, Functional traits and ecological affinities of riparian plants along the Colorado River in Grand Canyon: Western North American Naturalist, v. 77, no. 1, p. 22--30, http://scholarsarchive.byu.edu/wnan/vol77/iss1/3.

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Year Published: 2017

Matching seed to site by climate similarity: techniques to prioritize plant materials development and use in restoration

Land management agencies are increasing the use of native plant materials for vegetation treatments to restore ecosystem function and maintain natural ecological integrity. This shift toward the use of natives has highlighted a need to increase the diversity of materials available. A key problem is agreeing on how many, and which, new accessions...

Doherty, Kyle; Butterfield, Bradley J.; Wood, Troy E.
Doherty, K.D., Butterfield, B.J., and Wood, T.E., 2017, Matching seed to site by climate similarity: techniques to prioritize plant materials development and use in restoration, v. 27, no. 3, p. 1010-1023, http://dx.doi.org/10.1002/eap.1505.

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Year Published: 2017

Local biotic adaptation of trees and shrubs to plant neighbors

Natural selection as a result of plant–plant interactions can lead to local biotic adaptation. This may occur where species frequently interact and compete intensely for resources limiting growth, survival, and reproduction. Selection is demonstrated by comparing a genotype interacting with con- or hetero-specific sympatric neighbor genotypes with...

Grady, Kevin C.; Wood, Troy E.; Kolb, Thomas E.; Hersch-Green, Erika; Shuster, Stephen M.; Gehring, Catherine A.; Hart, Stephen C.; Allan, Gerard J.; Whitham, Thomas G.

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Year Published: 2017

Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or...

Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody B.; Reed, Sasha C.
Rutherford W.A., Painter T.H., Ferrenberg S., Belnap J., Okin G.S., Flagg C., Reed S.C. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts Scientific Reports 7, Article number: 44188 (2017)

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Year Published: 2017

Importance of the 2014 Colorado River Delta pulse flow for migratory songbirds: Insights from foraging behavior

The Lower Colorado River provides critical riparian areas in an otherwise arid region and is an important stopover site for migrating landbirds. In order to reverse ongoing habitat degradation due to drought and human-altered hydrology, a pulse flow was released from Morelos Dam in spring of 2014, which brought surface flow to dry stretches of the...

Darrah, Abigail J.; Greeney, Harold F.; van Riper, Charles
Darrah, Abigail .J., Harold F. Greeney and Charles van Riper III. 2016. Importance of the 2014 Colorado River Delta pulse flow for migratory songbirds: Insights from foraging behavior. Ecological Engineering. early online. Full cite to follow.

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Year Published: 2017

Pushing precipitation to the extremes in distributed experiments: Recommendations for simulating wet and dry years

Intensification of the global hydrological cycle, ranging from larger individual precipitation events to more extreme multiyear droughts, has the potential to cause widespread alterations in ecosystem structure and function. With evidence that the incidence of extreme precipitation years (defined statistically from historical precipitation records...

Knapp, Alan K.; Avolio, Meghan L.; Beier, Claus; Carroll, Charles J.W.; Collins, Scott L.; Dukes, Jeffrey S.; Fraser, Lauchlan H.; Griffin-Nolan, Robert J.; Hoover, David L.; Jentsch, Anke; Loik, Michael E.; Phillips, Richard P.; Post, Alison K.; Sala, Osvaldo E.; Slette, Ingrid J.; Yahdjian, Laura; Smith, Melinda D.
Knapp, A.K., M.L. Avolio, C. Beier, C.J.W. Carroll, S.L. Collins, J.S. Dukes,, L. H. Fraser, R..J. Griffin-Nolan, D. L. Hoover, A. Jentsch, M.E. Loik, R. P. Phillps, A.K. Post, O.E. Sala, I.J. Slette, L. Yahdjian and M.D. Smith. (2016), Pushing precipitation to the extremes in distributed experiments: recommendations for simulating wet and dry years. Glob Change Biol. doi:10.1111/gcb.13504 http://onlinelibrary.wiley.com/doi/10.1111/gcb.13504/full

Filter Total Items: 239
Image: Killdeer
May 10, 2006

Killdeer

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Cattle Egret
May 5, 2006

Cattle Egret

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Black Bellied Plover
May 5, 2006

Black Bellied Plover

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Andrew Schwartz and Dan Hanes hold a current profiler for a study of surf-zone hydrodynamics at Ocean Beach, San Francisco.
January 30, 2006

Studying Surf-Zone Hydrodynamics

USGS scientists Andrew Schwartz and Dan Hanes maneuver a current profiler for a study of surf-zone hydrodynamics at Ocean Beach, on the west side of San Francisco, California. Beach erosion has been a continuing problem in this area. This fieldwork is part of an effort to document, analyze, and simulate the processes that control sand transport and sedimentation patterns

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A home, severely damaged by the tsunami that hit Sumatra on December 26, 2004, sits atop debris.
January 21, 2005

Heavily damaged home in Banda Aceh, Sumatra from the 2004 tsunami

A severely damaged home, or a portion of one, sits atop debris in Banda Aceh on the island of Sumatra. Damage was caused by a massive, highly destructive tsunami, triggered by a magnitude 9.1 earthquake just offshore of Sumatra, on December 26, 2004.

Moutain Diablo in the early morning
December 31, 2004

Mt. Diablo from Suisun Marsh

Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.

Attribution: Southwest
Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.
December 31, 2003

Water quality sampling on San Francisco Bay

USGS conducts water quality sampling to describe changes in water quality along the deep channel of the San Francisco Bay-Delta system. Sampling includes continuious sampling and discrete sampling. Here a water discrete water sample is collected using a Niskin sampler at sunset in north San Francisco Bay.

Evaportranspiration equipment along the Tracy Segment, Nevada
April 30, 2003

Evaportranspiration equipment along the Tracey Segment

Evaportranspiration equipment along the Tracey Segment

USGS regional research drill rig near Truckee River, NV
June 9, 2001

USGS regional research drill rig near Truckee River, NV

USGS regional research drill rig constructing sites near the south bank of the Truckee River just downstream of USGS 10350000 Truckee River at Vista. The wells were constructed to investigate surface water groundwater interaction.

Irrigation ditch alongside an agricultural field.
December 31, 2000

Irrigation ditch alongside an agricultural field in California's Central Valley

Irrigation systems in Central California Valley Ecoregion: Single-field irrigation ditch.

Attribution: Southwest
Grasslands and agricultural fields in the flat foreground, with housing development on the hills beyond.
December 31, 2000

Grasslands and agricultural fields, with housing development on the hills beyond.

Conversions of grassland/shrubland and agriculture to developed land were two common land-cover changes in Southern and Central California Chaparral and Oak Woodlands Ecoregion.

Attribution: Southwest

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