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Filter Total Items: 2,154
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Year Published: 2018

Ecohydrological implications of aeolian sediment trapping by sparse vegetation in drylands

Aeolian processes are important drivers of ecosystem dynamics in drylands, and important feedbacks exist among aeolian—hydrological processes and vegetation. The trapping of wind‐borne sediments by vegetation canopies may result in changes in soil properties beneath the vegetation, which, in turn, can alter hydrological and biogeochemical...

Gonzales, Howell B.; Ravi, Sujith; Li, Junran; Sankey, Joel B.
Gonzales, H.B., Ravi, S., Li, J., Sankey, J.B., 2018, Ecohydrological implications of aeolian sediment trapping by sparse vegetation in drylands: Ecohydrology, early view available online at https://doi.org/10.1002/eco.1986.

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Year Published: 2018

Managing salinity in Upper Colorado River Basin streams: Selecting catchments for sediment control efforts using watershed characteristics and random forests models

Elevated concentrations of dissolved-solids (salinity) including calcium, sodium, sulfate, and chloride, among others, in the Colorado River cause substantial problems for its water users. Previous efforts to reduce dissolved solids in upper Colorado River basin (UCRB) streams often focused on reducing suspended-sediment transport to streams, but...

Tillman, Fred; Anning, David W.; Heilman, Julian A.; Buto, Susan G.; Miller, Matthew P.
Tillman, F.D, Anning, D.W., Heilman, J.A, Buto, S.G., and Miller, M.P., 2018, Managing salinity in upper Colorado River basin streams: Selecting catchments for sediment control efforts using watershed characteristics and random forests models: Water, 10, 676, https://doi.org/10.3390/w10060676

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Year Published: 2018

The thermophysical properties of the Bagnold Dunes, Mars: Ground truthing orbital data

We compare the thermophysical properties and particle sizes derived from the Mars Science Laboratory rover's Ground Temperature Sensor of the Bagnold dunes, specifically Namib dune, to those derived orbitally from Thermal Emission Imaging System, ultimately linking these measurements to ground truth particle sizes determined from Mars Hand Lens...

Edwards, Christopher S.; Piqueux, Sylvain; Hamilton, Victoria E.; Fergason, Robin L.; Herkenhoff, Kenneth E.; Vasavada, Ashwin R.; Bennett, Kristen A.; Sacks, Leah; Lewis, Kevin; Smith, Michael D.

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Year Published: 2018

Effect of river confinement on depth and spatial extent of bed disturbance affecting salmon redds

Human impacts on rivers threaten the natural function of riverine ecosystems. This paper assesses how channel confinement affects the scour depth and spatial extent of bed disturbance and discusses the implications of these results for salmon-redd disturbance in gravel-bedded rivers. Two-dimensional hydrodynamic models of relatively confined and...

Christiana R. Czuba; Czuba, Jonathan A. ; Magirl, Christopher S.; Gendaszek, Andrew S.; Konrad, Christopher P.

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Year Published: 2018

Ecosystem thresholds, tipping points, and critical transitions

Abrupt shifts in ecosystems are cause for concern and will likelyintensify under global change (Scheffer et al., 2001). The terms‘thresho lds’, ‘tipping points’, and ‘critical transitions’ have beenused interchangeably to refer to sudden changes in the integrityor state of an ecosystem caused by environmental drivers(Holling, 1973; May, 1977)....

Munson, Seth M.; Reed, Sasha C.; Peñuelas, Josep; McDowell, Nathan G.; Sala, Osvaldo E.
Munson, S.M., Reed, S.C., Peñuelas, J., McDowell, N.G., and Sala, O.E., 2018, Ecosystem thresholds, tipping points, and critical transitions: New Phytologist, v. 218, p. 1315-1317, https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.15145.

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Year Published: 2018

Preliminary synthesis and assessment of environmental flows in the middle Verde River watershed, Arizona

A 3-year study was undertaken to evaluate the suitability of the available modeling tools for characterizing environmental flows in the middle Verde River watershed of central Arizona, describe riparian vegetation throughout the watershed, and estimate sediment mobilization in the river. Existing data on fish and macroinvertebrates were analyzed...

Paretti, Nicholas V.; Brasher, Anne M. D.; Pearlstein, Susanna L.; Skow, Dena M.; Gungle, Bruce W.; Garner, Bradley D.
Paretti, N.V., Brasher, A.M.D., Pearlstein, S.L., Skow, D.M., Gungle, Bruce, and Garner, B.D., 2018, Preliminary synthesis and assessment of environmental flows in the middle Verde River watershed, Arizona: U.S. Geological Survey Scientific Investigations Report 2017–5100, 104 p., https://doi.org/10.3133/sir20175100.

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Year Published: 2018

Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2

We investigated how properties of soil organic matter (SOM) were altered after 10 years exposure to elevated atmospheric CO2 concentration ([CO2]) in a Mojave Desert ecosystem, using plant and microbial biomarkers. We focused on roles of Larrea tridentata, the dominant evergreen shrub which form islands of fertility, and ...

Koyama, Akihiro; Harlow, Benjamin; Kuske, Cheryl R.; Belnap, Jayne; Evans, R. Dave
Koyama, A., Harlow, B., Kuske, C.R., Belnap, J., and Evans, R.D., 2018, Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2: Soil Biology and Biochemistry, v. 120, p. 48-57, https://doi.org/10.1016/j.soilbio.2018.01.033.

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Year Published: 2018

Spatial distribution of estuarine diamond-backed terrapins (Malaclemys terrapin) and risk analysis from commercial blue crab (Callinectes sapidus) trapping at the Savannah Coastal Refuges Complex, USA

The diamond-backed terrapin (Malaclemys terrapin) is a small estuarine turtle distributed along the Atlantic and Gulf Coasts of the USA. Terrapin populations are declining throughout their range and one of the main causes is mortality by drowning as bycatch in commercially-fished blue crab (Callinetes sapidus) traps (aka pots). We conducted head...

Lovich, Jeffrey E.; Thomas, Meagan; Ironside, Kirsten E.; Yackulic, Charles B.; Puffer, Shellie R.
Lovich, J.E., Thomas, M., Ironside, K., Yackulic, C., and Puffer, S.R., 2018, Spatial distribution of estuarine diamond-backed terrapins (Malaclemys terrapin) and risk analysis from commercial blue crab (Callinectes sapidus) trapping at the Savannah Coastal Refuges Complex, USA: Ocean and Coastal Management, v. 157, p. 160-167, https://doi.org/10.1016/j.ocecoaman.2018.02.012.

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Year Published: 2018

Population dynamics of the northern tamarisk beetle (Diorhabda carinulata) in the Colorado River Basin

Throughout the Southwestern United States, riparian systems contain narrow belts of vegetation along streams and rivers. Although only a small percentage of the total land cover, this ecosystem is important for maintaining high species diversity and population densities of birds. Anthropogenic changes to Western riverine systems have enhanced...

Jamison, Levi R.; van Riper, Charles
Jamison, L.R., and van Riper, C., III, 2018, Population dynamics of the northern tamarisk beetle (Diorhabda carinulata) in the Colorado River Basin: U.S. Geological Survey Open-File Report 2018–1070, 67 p., https://doi.org/10.3133/ofr20181070.

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Year Published: 2018

Measuring impact crater depth throughout the solar system

One important, almost ubiquitous, tool for understanding the surfaces of solid bodies throughout the solar system is the study of impact craters. While measuring a distribution of crater diameters and locations is an important tool for a wide variety of studies, so too is measuring a crater's “depth.” Depth can inform numerous studies including...

Robbins, Stuart J.; Watters, Wesley A.; Chappelow, John E.; Bray, Veronica J.; Daubar, Ingrid J.; Craddock, Robert A.; Beyer, Ross A.; Landis, Margaret E.; Ostrach, Lillian; Tornabene, Livio L.; Riggs, Jamie D.; Weaver, Brian P.
Robbins, S.J. et al., 2018. Measuring impact crater depth throughout the solar system. Meteoritics and Planetary Science, 53(4), 583-626.

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Year Published: 2018

The response of source-bordering aeolian dunefields to sediment-supply changes 1: Effects of wind variability and river-valley morphodynamics

Source-bordering dunefields (SBDs), which are primarily built and maintained with river-derived sediment, are found in many large river valleys and are currently impacted by changes in sediment supply due to climate change, land use changes, and river regulation. Despite their importance, a physically based, applied approach for quantifying the...

Sankey, Joel B.; Kasprak, Alan; Caster, Joshua; East, Amy E.; Fairley, Helen C.
Sankey, J.B., Kasprak, A., Caster, J.J., East, A.E., and Fairley, H., 2018, The response of source-bordering aeolian dunefields to sediment-supply changes 1--Effects of wind variability and river-valley morphodynamics: Aeolian Research, v. 32, p. 228-245, https://doi.org/10.1016/j.aeolia.2018.02.005.

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Year Published: 2018

The response of source-bordering aeolian dunefields to sediment-supply changes 2: Controlled floods of the Colorado River in Grand Canyon, Arizona, USA

In the Colorado River downstream of Glen Canyon Dam in the Grand Canyon, USA, controlled floods are used to resupply sediment to, and rebuild, river sandbars that have eroded severely over the past five decades owing to dam-induced changes in river flow and sediment supply. In this study, we examine whether controlled floods, can in turn resupply...

Sankey, Joel B.; Caster, Joshua; Kasprak, Alan; East, Amy E.
Sankey, J.B., Caster, J.J., Kasprak, A., and East, A.E., 2018, The response of source-bordering aeolian dunefields to sediment-supply changes 2--Controlled floods of the Colorado River in Grand Canyon, Arizona, USA: Aeolian Research, v. 32, p. 154-169, https://doi.org/10.1016/j.aeolia.2018.02.004.

Filter Total Items: 239
lone road lined by palm trees on a small flat island, with water from the sea washing over the road
March 31, 2014

Wave-driven flooding and overwash on Roi-Namur Atoll

Wave-driven flooding and overwash on Roi-Namur Atoll, Republic of the Marshall Islands

coastal road and palm trees on a small flat island, with water waves from the sea washing over the road
March 31, 2014

Wave-driven flooding and overwash on Roi-Namur Atoll

Wave-driven flooding and overwash on Roi-Namur Atoll, Republic of the Marshall Islands

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January 2, 2014

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Attribution: Southwest
October 7, 2013

Animal Interactions at Wind Energy Facilities – Gray Fox

There were two documented gray fox visits at the burrows, making them the third most documented predator. Gray foxes are implicated predators of various life stages of desert tortoises, but it is difficult to catch them in the act. In this case, a gray fox approaches a burrow, and thoroughly investigates the burrow mouth. The fox develops an arch in its tail (slight

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October 5, 2013

Animal Interactions at Wind Energy Facilities – Western Spotted Skunk

There was one documented skunk event captured on camera - the least documented predator. Here, a western spotted skunk is thoroughly investigating the burrow of one of the marked female tortoises in the study population. Western spotted skunks are known predators of turtle eggs. The skunk investigated the area within the burrow for a full minute before it appears outside

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August 31, 2013

Busy Day in the Sed Lab

Time lapse video of Angela Tan working in a USGS sediment analysis laboratory. More at https://walrus.wr.usgs.gov/labs/coresedlab.html

two men wearing hard hats carrying a 4-foot long auger in a grassy field
August 17, 2013

USGS scientists carrying an auger to a drill hole for seismic survey

USGS scientists Robert Sickler (left) and Rufus Catchings (right) carrying an auger to a drill hole for seismic survey.

two men wearing hard hats attaching a section of an auger to a drill
August 17, 2013

USGS scientists attach an auger to drill for seismic survey

USGS scientists Robert Sickler (below) and Rufus Catchings (standing) attaching a section of an auger bit in order to drill a hole for a seismic survey.

June 30, 2013

Animal Interactions at Wind Energy Facilities – Bobcat

In this video, a bobcat approached a desert tortoise (a marked female in the study population) that was sleeping on the apron of her burrow. Bobcats are known predators of various life stages of the desert tortoise. In this case, the bobcat bent down to sniff the tortoise, and then touched its paw to the top of the tortoise's shell. The tortoise then moved into an "all-

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June 22, 2013

Animal Interactions at Wind Energy Facilities – American Black Bear

This American black bear and cub duo was seen simply investigating a tortoise burrow, and although it is surprising to see a black bear so low in elevation, it isn't impossible. The study site, Mesa, sits at the intersection of multiple ecosystems (Sonoran Desert, Mojave Desert, montane, and coastal sage scrub). Therefore, the bears could have come down from the montane

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June 22, 2013

Animal Interactions at Wind Energy Facilities – Coyotes

Coyotes were the second most frequently observed mammalian predator on the trail cameras. Coyotes are considered one of the primary predators of desert tortoises. In this instance, a coyote is passing by a burrow when it suddenly has a change in attention as it is passing by. It then approaches the burrow and sniffs all around the burrow entrance (including the apron and

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USGS and US Forest Service staff installing dust monitoring equipment at a uranium mine near Grand Canyon National Park.
May 31, 2013

USGS and US Forest Service staff installing dust monitoring equipment

USGS and US Forest Service staff installing dust monitoring equipment at a uranium mine near Grand Canyon National Park.

Climate change combined with overlapping high-intensity land uses are likely to create conditions detrimental to the recreation economy, wildlife habitat, water availability and other resources in hyper-arid landscapes, or drylands, in the future

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