Search USGS⌕ Search

SEARCH · Search USGS

Results for “Materials Performance”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
USGS2026

Refinement of a framework for Moving Aircraft River Velocimetry (MARV) and application to particle tracking along Alaskan rivers

Information on river velocities enhances understanding flood hazards, evaluating habitat conditions, and predicting the transport of floating materials. In this follow-up study, we used data from two new sites, one with a more complex morphology and the other with a lower suspended sediment concentration, to provide further evidence that Moving Aircraft River Velocimetry (MARV) can yield accurate velocity estimates ( R 2 up to 0.87 when compared to field measurements) for long segments of large, turbid rivers. The MARV workflow is packaged in freely available software and is robust to implementation details; neither buffering to mitigate edge effects nor a new approach to aggregating velocity vectors improved performance. MARV was not sensitive to parameters used to establish overlapping image sequences, but combining a long window with a short jump between consecutive windows was the optimal configuration. Although accuracy varied from one cross section to the next, agreement between remotely sensed velocities and those measured in the field was independent of position within a frame range. As an initial step toward application of the approach to help address practical problems, we showed how MARV can drive particle tracking models. Our first-order simulations suggest that channel morphology and flow velocity are the primary controls on travel time and particle fate, with diffusive processes playing a lesser role. Although MARV can be used to characterize an instantaneous flow field, a more comprehensive framework that accounts for other physical processes would be required to model specific types of events like oil spills.

Alaska↗
USGS2004

Surficial geologic map of the southeast Memphis Quadrangle, Shelby County, Tennessee

The depiction of geology on this map is designed to aid in urban planning and analysis of potential damage in the event of strong earthquake motion. The geologic map by itself does not analyze potential earthquake damage, but is designed to be used by seismologists who perform such analyses. Wind-deposited silt and clayey silt (loess) is the predominant surficial deposit. Loess entirely covers the upland (everyplace in the map area that is not a valley occupied by a stream) to depths of 4.5-16 m. The second most abundant deposit is silty alluvium, which is confined to the narrow floodplains and is 1-10 m thick. Sparse, unconsolidated, pebbly sand alluvium is 0.5-3 m thick and is confined to point bars and channel deposits in the narrow, incised channel of Nonconnah Creek. The nature of geologic materials to a degree determines the severity of damage to infrastructure sustained during a strong earthquake.

Scientific Investigations Map↗
USGS2016

ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars

At Gale crater, Mars, ChemCam acquired its first laser-induced breakdown spectroscopy (LIBS) target on Sol 13 of the landed portion of the mission (a Sol is a Mars day). Up to Sol 800, more than 188 000 LIBS spectra were acquired on more than 5800 points distributed over about 650 individual targets. We present a comprehensive review of ChemCam scientific accomplishments during that period, together with a focus on the lessons learned from the first use of LIBS in space. For data processing, we describe new tools that had to be developed to account for the uniqueness of Mars data. With regard to chemistry, we present a summary of the composition range measured on Mars for major-element oxides (SiO 2 , TiO 2 , Al 2 O 3 , FeO T , MgO, CaO, Na 2 O, K 2 O) based on various multivariate models, with associated precisions. ChemCam also observed H, and the non-metallic elements C, O, P, and S, which are usually difficult to quantify with LIBS. F and Cl are observed through their molecular lines. We discuss the most relevant LIBS lines for detection of minor and trace elements (Li, Rb, Sr, Ba, Cr, Mn, Ni, and Zn). These results were obtained thanks to comprehensive ground reference datasets, which are set to mimic the expected mineralogy and chemistry on Mars. With regard to the first use of LIBS in space, we analyze and quantify, often for the first time, each of the advantages of using stand-off LIBS in space: no sample preparation, analysis within its petrological context, dust removal, sub-millimeter scale investigation, multi-point analysis, the ability to carry out statistical surveys and whole-rock analyses, and rapid data acquisition. We conclude with a discussion of ChemCam performance to survey the geochemistry of Mars, and its valuable support of decisions about selecting where and whether to make observations with more time and resource-intensive tools in the rover's instrument suite. In the end, we present a bird's-eye view of the many scientific results: discovery of felsic Noachian crust, first observation of hydrated soil, discovery of manganese-rich coatings and fracture fills indicating strong oxidation potential in Mars' early atmosphere, characterization of soils by grain size, and wide scale mapping of sedimentary strata, conglomerates, and diagenetic materials.

Journal of Analytical Atomic Spectrometry↗
USGS2024

Trace silicon determination in biological samples by inductively coupled plasma mass spectrometry (ICP-MS): Insight into volatility of silicon species in hydrofluoric acid digests for optimal sample preparation and introduction to ICP-MS

A method for the determination of trace levels of silicon from biological materials by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. The volatility of water-soluble silicon species, hexafluorosilicic acid (H 2 SiF 6 ), and sodium metasilicate (Na 2 SiO 3 ) was investigated by evaporating respective solutions (50 µg/mL silicon) in nitric acid (HNO 3 ), nitric acid + hydrochloric acid (HNO 3 + HCl), and nitric acid + hydrochloric acid + hydrofluoric acid (HNO 3 + HCl + HF) at 120 °C on a hot-block to near dryness. The loss of silicon from H 2 SiF 6 solutions was substantial (>99%) regardless of the digestion medium. Losses were also substantial (>98%) for metasilicate solutions heated in HNO 3 + HCl + HF, while no significant loss occurred in HNO 3 or HNO 3 + HCl. These results show that H 2 SiF 6 species were highly volatile and potential losses could confound accuracy at trace level determinations by ICP-MS if digestates prepared in HF are heated to eliminate HF. Among the various matrices comprising major elements, sodium appeared to be effective in reducing silicon loss from H 2 SiF 6 solutions. Excess sodium chloride (NaCl) matrix provided better stability, improving silicon recoveries by up to about 80% in evaporated HF digestates of soil and mine waste samples, but losses could not be fully prevented. To safely remove excess acids and circumvent the adverse effects of excess HF (e.g., risk of high Si background signals), a two-step digestion scheme was adopted for the preparation of biological samples containing trace silicon levels. A closed-vessel digestion was performed either in 4 mL of concentrated HNO 3 and 1 mL of concentrated HCl or 4 mL of concentrated HNO 3 , 1 mL of concentrated HCl and 1 mL of concentrated HClO 4 on a hot plate at 140 °C. Digestates were then evaporated to incipient dryness at 120 °C to remove the acids. A second closed-vessel digestion was carried out to dissolve silicates in 0.5 mL of concentrated HNO 3 and 0.5 mL of concentrated HF at 130 °C. After digestion, digestates were diluted to 10 mL. The solution containing about 5% HNO 3 and 5% HF was directly analyzed by ICP-MS equipped with an HF-inert sample introduction system. The limit of detection was about 110 µg/L for 28 Si when using the Kinetic Energy Discrimination (KED) mode. The method was used to determine silicon in various plant and tissue certified reference materials. Data were acquired for 28 Si using KED and standard (STD) modes, and 74 Ge and 103 Rh as internal standard elements. There was not any significant difference between the accuracy and precision of the results obtained with 74 Ge and 103 Rh within the same measurement mode. Precision, calculated as relative standard deviation for four replicate analyses, varied from 5.3 (tomato leaves) to 21% (peach leaves) for plant and from 2.2 (oyster tissue) to 33% (bovine liver) for tissue SRM/CRMs. Poor precision was attributed to material heterogeneity and the large particle size distribution. An analysis of lung tissue samples from those with occupational exposure to silica dust revealed that tissues possessed substantial levels of water-soluble silicates, but the most silicon was present in the particulate matter fraction.

Minerals↗
USGS2022

Seismic site characterization with shear wave (SH) reflection and refraction methods

Reflection and critically refracted seismic methods use traveltime measurements of body waves propagating between a source and a series of receivers on the ground surface to calculate subsurface velocities. Body wave energy is refracted or reflected at boundaries where there is a change in seismic impedance, defined as the product of material density and seismic velocity. This article provides practical guidance on the use of horizontally propagating shear wave (SH-wave) refraction and reflection methods to determine shear wave velocity as a function of depth for near-surface seismic site characterizations. Method principles and the current state of engineering practice are reviewed, along with discussions of limitations and uncertainty assessments. Typical data collection procedures are described using basic survey equipment, along with information on more advanced applications and emerging technologies. Eight case studies provide examples of the techniques in real-world seismic site characterizations performed in a variety of geological settings.

Journal of Seismology↗
USGS1967

Effects of the earthquake of March 27, 1964, at Seward, Alaska

Seward, in south-central Alaska, was one of the towns most devastated by the Alaska earthquake of March 27, 1964. The greater part of Seward is built on an alluvial fan-delta near the head of Resurrection Bay on the southeast coast of the Kenai Peninsula. It is one of the few ports in south-central Alaska that is ice free all year, and the town’s economy is almost entirely dependent upon its port facilities. The Alaska earthquake of March 27, 1964, magnitude approximately 8.3–8.4, began at 6:36 p.m. Its epicenter was in the northern part of the Prince William Sound area; focal depth was 20–50 km. Strong ground motion at Seward lasted 3–4 minutes. During the shaking, a strip of land 50–400 feet wide along the Seward waterfront, together with docks and other harbor facilities, slid into Resurrection Bay as a result of large-scale submarine landsliding. Fractures ruptured the ground for'severa1 hundred feet back from the landslide scarps. Additional ground was fractured in the Forest Acres subdivision and on the alluvial floor of the Resurrection River valley; fountaining and sand boils accompanied the ground fracturing. Slide-generated wares, possibly seiche waves, and seismic sea waves crashed onto shore; ware runup was as much as 30 feet above mean lower low water and caused tremendous damage; fire from burning oil tanks added to the destruction. Damage from strong ground motion itself was comparatively minor. Tectonic subsidence of about 3.6 feet resulted in low areas being inundated at high tide. Thirteen people were killed and five were injured as a result of the earthquake. Eighty-six houses were totally destroyed and 260 were heavily damaged. The harbor facilities were almost completely destroyed, and the entire economic base of the town was wiped out. The total cost to replace the destroyed public and private facilities was estimated at $22 million. Seward lies on the axis of the Chugach Mountains geosyncline. The main structural trend in the mapped area, where the rocks consist almost entirely of graywacke and phyllite, is from near north to N. 20° E. Beds and cleavage of the rocks commonly dip 70° W. or NW. to near vertical. Locally, the rocks are complexly folded or contorted. So major faults were found in the mapped area, but small faults, shear zones, and joints are common. Surficial deposits of the area hare been divided for mapping into the following units: drift deposits, alluvial fan deposits, valley alluvium, intertidal deposits, landslide deposits, and artificial fill. Most of these units intergrade and were deposited more or less contemporaneously. The drift deposits consist chiefly of till that forms moraines along the lower flanks of the Resurrection River valley and up tributary valleys. The till is predominantly silt and sand and lesser amounts of clay-size particles, gravel, cobbles, and boulders. Glacial outwash and stratified ice-contact deposits constitute the remainder of the drift deposits. Fans and fan-deltas have been deposited at the valley mouths of tributary streams. Some, including the one upon which Seward built, project into Resurrection Bay, and deltaic-type deposits form their distal edges. The larger fans—composed chiefly of loosely compacted and poorly sorted silt, sand, and gravel—form broad aprons having low gradients. The fan deposits range in thickness from about 100 feet to possibly several hundred feet and, at least in some places, lie on a platform of compact drift. Smaller fans at the mouths of several canyons have steep gradients and considerable local relief. Valley alluvium, deposited chiefly by the Resurrection River, consists mostly of coarse sand and fine to medium gravel. In the axial part of the valley it is probably more than 100 feet thick. Near the head of Resurrection Bay, the alluvium is underlain by at least 75 feet of marine deltaic sediments, which are in turn underlain by 600 or more feet of drift in the deepest part of the bedrock valley. Beach, deltaic, and estuarine sediments, deposited on intertidal flats at the head of the bay and along far1 margins that extend into the bay, arc mapped as intertidal deposits. They consist mostly of silt, sand, and fine gravel, and lesser amounts of clay-size particles. The earthquake reactivated old slides and trigged new ones in the mountains. Rock and snow avalanches, debris flows, and creep of talus deposits characterized slide activity on the steeper slops. The Seward waterfront had been extended before the earthquake by adding artificial fill consisting of loose sand and gravel; part of the lagoon area had been filled with refuse. After the earth- quake, fill, consisting of silt and sand dredged from the head of the bay, was pumped onto part of the lagoon area and also on land at the northwest corner of the bay. Response to the disaster was immediate and decisive. City, State, and Federal agencies, as well as other organizations and individuals, gave unstintingly of their time and facilities. Within a few days, there was temporary restoration of water, sewerage, and electrical facilities. The U.S. Army Corps of Engineers was authorized to select sites and construct a new dock for the Alaska Railroad, a new small-boat basin, and related facilities. The firm of Shannon and Wilson, Inc., under contract to the Corps of Engineers, investigated subsurface soils extensively to determine the factors responsible for the sliding along the Seward waterfront and to assist in site selection for reconstruction of the destroyed harbor facilities. Borings also made along the Seward waterfront and at the head of the bay, and laboratory tests were conducted on pertinent samples. These studies were augmented by geophysical studies both on land and in the bay. In addition, the Corps of Engineers made shallow borings on the intertidal flats at the head of the bay and performed pile-driving and load tests. Borings also were drilled and test pits were dug in the subdivision of Forest Acres. Sliding along the Seward waterfront markedly deepened the water along the former shoreline. Post-earthquake slopes of the bay floor immediately offshore also are steeper in places than before the earthquake. The strong ground motion of the earthquake triggered the landsliding, but several factors may have contributed to the magnitude and characteristics of the slides. These factors are: (1) the long duration of strong ground motion, (2) the grain size and texture of the material involved in the sliding, (3) the probability that the finer grained materials liquefied and flowed seaward, and (4) the added load of manmade facilities built on the edge of the shore, Secondary effects of the slides themselves—sudden drawdown of water, followed by the weight of returning waves—also may have contributed to the destruction. Submarine sliding at the northwest corner of the bay occurred in fine-grained deltaic deposits whose frontal slopes probably were in metastable equilibrium under static conditions. Uplift pressures from aquifers under hydrostatic head, combined with the probable liquefaction characteristics of the sediments when vibrated by strong ground motion, probably caused the material to slide and flow seaward as a heavy slurry. Under static conditions, no major shoreline or submarine landsliding is expected in the Seward area; in the event of another severe earthquake, however, additional sliding is likely along the Seward waterfront and also in the deltaic deposits at the northwest corner of the bay. Fractured ground in back of the present shoreline along the Seward waterfront is an area of incipient landslides that would be unstable under strong shaking. For this reason the Scientific and Engineering Task Force placed the area in a high-risk classification and recommended no repair, rehabilitation, or new construction in this area involving use of Federal funds; it was further recommended that the area should be reserved for park or other uses that do not involve large congregations of people. The deltaic deposits at the head of the bay probably also would be susceptible to sliding during another large earthquake. This sliding would result in further landward retreat of the present shoreline toward the new railroad dock. Specifications for the new dock, whose seaward end is now approximately 1,100 feet from the back scarp of the subaqueous landslide, require design pro- visions to withstand seismic shock up to certain limits. Earthquake-induced fracturing of the ground in the subdivision of Forest Acres was confined to the lower part of a broad alluvial fan. There, sewer and water lines were ruptured and the foundations of some homes were heavily damaged. Landsliding, such as occurred along the shoreline of the bay, was not a contributing cause of the fracturing. Two hypotheses are offered to explain the fracturing: 1. Seismic energy was transformed into visible surface waves of such amplitude that the strength of surface layer was exceeded and rupturing occurred; tensional and compressional stresses alternately opened and closed the fractures and forced out water and mud. 2. Compaction by vibration of the fine-grained deposits of the fan caused ground settlement and fracturing; ground water under temporary hydrostatic head was forced to the surface as fountains and carried the finer material with it. Water waves that crashed onto shore, while shaking was still continuing, were generated chiefly by onshore and offshore landsliding. Waves that overran the shores about 25 minutes after shaking stopped and that continued to arrive for the next several hours are believed to be seismic sea waves (tsunamis) that originated in an uplifted area in the Gulf of Alaska. During the time of seismic sea-wave activity and perhaps preceding it, seiche wares also may have been generated within Resurrection Bay and complicated the wave effects along the shoreline.

Alaska↗
USGS2012

Bathymetric and underwater video survey of Lower Granite Reservoir and vicinity, Washington and Idaho, 2009-10

The U.S. Geological Survey conducted a bathymetric survey of the Lower Granite Reservoir, Washington, using a multibeam echosounder, and an underwater video mapping survey during autumn 2009 and winter 2010. The surveys were conducted as part of the U.S. Army Corps of Engineer's study on sediment deposition and control in the reservoir. The multibeam echosounder survey was performed in 1-mile increments between river mile (RM) 130 and 142 on the Snake River, and between RM 0 and 2 on the Clearwater River. The result of the survey is a digital elevation dataset in ASCII coordinate positioning data (easting, northing, and elevation) useful in rendering a 3×3-foot point grid showing bed elevation and reservoir geomorphology. The underwater video mapping survey was conducted from RM 107.73 to 141.78 on the Snake River and RM 0 to 1.66 on the Clearwater River, along 61 U.S. Army Corps of Engineers established cross sections, and dredge material deposit transects. More than 900 videos and 90 bank photographs were used to characterize the sediment facies and ground-truth the multibeam echosounder data. Combined, the surveys were used to create a surficial sediment facies map that displays type of substrate, level of embeddedness, and presence of silt.

Washington;Idaho↗
USGS2005

Summary of sediment data from the Yampa river and upper Green river basins, Colorado and Utah, 1993-2002

The water resources of the Upper Colorado River Basin have been extensively developed for water supply, irrigation, and power generation through water storage in upstream reservoirs during spring runoff and subsequent releases during the remainder of the year. The net effect of water-resource development has been to substantially modify the predevelopment annual hydrograph as well as the timing and amount of sediment delivery from the upper Green River and the Yampa River Basins tributaries to the main-stem reaches where endangered native fish populations have been observed. The U.S. Geological Survey, in cooperation with the Colorado Division of Wildlife and the U.S. Fish and Wildlife Service, began a study to identify sediment source reaches in the Green River main stem and the lower Yampa and Little Snake Rivers and to identify sediment-transport relations that would be useful in assessing the potential effects of hydrograph modification by reservoir operation on sedimentation at identified razorback spawning bars in the Green River. The need for additional data collection is evaluated at each sampling site. Sediment loads were calculated at five key areas within the watershed by using instantaneous measurements of streamflow, suspended-sediment concentration, and bedload. Sediment loads were computed at each site for two modes of transport (suspended load and bedload), as well as for the total-sediment load (suspended load plus bedload) where both modes were sampled. Sediment loads also were calculated for sediment particle-size range (silt-and-clay, and sand-and-gravel sizes) if laboratory size analysis had been performed on the sample, and by hydrograph season. Sediment-transport curves were developed for each type of sediment load by a least-squares regression of logarithmic-transformed data. Transport equations for suspended load and total load had coefficients of determination of at least 0.72 at all of the sampling sites except Little Snake River near Lily, Colorado. Bedload transport equations at the five sites had coefficients of determination that ranged from 0.40 (Yampa River at Deerlodge Park, Colorado) to 0.80 (Yampa River above Little Snake River near Maybell, Colorado). Transport equations for silt and clay-size material had coefficients of determination that ranged from 0.46 to 0.82. Where particle-size data were available (Yampa River at Deerlodge Park, Colorado, and Green River near Jensen, Utah), transport equations for the smaller particle sizes (fine sand) tended to have higher coefficients of determination than the equations for coarser sizes (medium and coarse sand, and very coarse sand and gravel). Because the data had to be subdivided into at least two subsets (rising-limb, falling-limb and, occasionally, base-flow periods), the seasonal transport equations generally were based on relatively few samples. All transport equations probably could be improved by additional data collected at strategically timed periods.

Scientific Investigations Report↗
USGS2022

Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2021 Report)

A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to provide the information necessary to overcome those challenges (e.g., Plant Conservation Alliance 2015; Breed et al. 2018; Winkler et al. 2018; McCormick et al. 2021). Many of the most complex information needs relate to identifying the appropriate sources of plant species that can successfully establish in dryland environments, like the Colorado Plateau, where low and highly variable precipitation is standard. Providing this information requires synergistic research efforts in which results from earlier investigations inform the design of subsequent investigations. The U.S. Geological Survey (USGS) Southwest Biological Science Center’s (SBSC’s) research activities to support CPNPP in FY21 followed the FY21 Statement of Work to support a research framework that is continually adapting based on the needs of the restoration community and results from previous investigations; the long-term research framework is outlined in the 2019-2023 5-Year Research Strategy (hereafter referred to as the 5-year plan). This research framework provides support for the National Seed Strategy for Rehabilitation and Restoration (Plant Conservation Alliance 2015), Biden-Harris Administration Executive Order 14008 (Tackling the Climate Crisis at Home and Abroad), and Department of Interior Priority #4 (Working to conserve at least 30% each of our lands and waters by the year 2030). Research activities in FY21 centered on landscape genomics, implementing and monitoring a common garden experiment near Vernal, UT, conducting experimental treatments using the GRID (Germination for Restoration Information and Decision-making) framework, and initiating new genetics projects to investigate the impact of production techniques on plant materials and restoration treatments on native plant communities. These activities were supported by four biological science technicians. The SARS-CoV-2 pandemic delayed some aspects of the FY21 workplan, especially for outside laboratory services. However, goals were largely met, and the overall progress of research remains on track with respect to the 5-year plan. While Dr. Rob Massatti was the only scientist supported by the SBSC-CPNPP agreement in FY21, other scientists, including Drs. John Bradford, Seth Munson, Mike Duniway, Sasha Reed, and Daniel Winkler, spent a considerable amount of time providing expertise and support for individual projects. Work activities performed in support of each 5-year plan goal are discussed in turn. Products resulting from FY21 research activities are reported in Appendix 1.

Arizona, Colorado, New Mexico, Utah↗
USGS1997

Level II scour analysis for Bridge 26 (WSTOTH00070026) on Town Highway 7, crossing Greendale Brook, Weston, Vermont

This report provides the results of a detailed Level II analysis of scour potential at structure WSTOTH00070026 on Town Highway 7 crossing Greendale Brook, Weston, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in south central Vermont. The 3.13-mi 2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest. In the study area, the Greendale Brook has a sinuous, non-incised, non-alluvial channel with a slope of approximately 0.015 ft/ft, an average channel top width of 38 ft and an average bank height of 3 ft. The channel bed material ranges from sand to boulder with a median grain size (D 50 ) of 64.8 mm (0.213 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 19, 1996, indicated that the reach was laterally unstable. The channel has moved to the right, however, scour countermeasures are in place along the upstream right bank. The Town Highway 7 crossing of the Greendale Brook is a 52-ft-long, two-lane bridge consisting of one 50-foot steel-beam span with a concrete deck (Vermont Agency of Transportation, written communication, April 07, 1995). The opening length of the structure parallel to the bridge face is 48.6 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 50 degrees to the opening while the opening-skew-to-roadway is 30 degrees. A scour hole 1.5 ft deeper than the mean thalweg depth was observed along the upstream right wingwall and right abutment during the Level I assessment. Scour protection measures at the site include: type-2 stone fill (less than 36 inches diameter) at the upstream end of the upstream left wingwall, along the left bank upstream, at the downstream end of the downstream left wing wall, and along the entire length of the downstream right wing wall; type 4 (less than 60 inches) and type-3 stone fill (less than 48 inches) along the right bank upstream. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 3.9 to 9.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). The Hire equation (abutment scour) is often used when the horizontal length blocked by flow divided by the depth of flow is greater than 25 (Richardson and others, 1995 p. 49). Although the Hire equation could be applied to the left abutment more conservative scour estimates were given by the Froehlich equation on the left abutment. Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

Vermont↗
USGS2023

Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2022 Report)

A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to provide the information necessary to overcome those challenges (e.g., Plant Conservation Alliance, 2015; Breed et al., 2018; Winkler et al., 2018; NASEM, 2023). Many of the most complex information needs relate to identifying the appropriate sources of plant species that can successfully establish in dryland environments, like the Colorado Plateau, where low and highly variable precipitation is standard. Providing this information requires synergistic research efforts in which results from earlier investigations inform the design of subsequent investigations. The U.S. Geological Survey (USGS) Southwest Biological Science Center’s (SBSC’s) research activities to support CPNPP in FY22 followed the FY22 Statement of Work to support a research framework that is continually adapting based on the needs of the restoration community and results from previous investigations; the long-term research framework is outlined in the 2019-2023 5-Year Research Strategy (hereafter referred to as the 5-year plan). This research framework provides support for the National Seed Strategy for Rehabilitation and Restoration (Plant Conservation Alliance, 2015), Biden-Harris Administration Executive Order 14008 (Tackling the Climate Crisis at Home and Abroad), and Department of Interior Priority #4 (Working to conserve at least 30% each of our lands and waters by the year 2030). Research activities in FY22 centered on landscape genomics, monitoring common garden and seeding experiments near Vernal and Moab, UT, conducting experimental treatments using the GRID (Germination for Restoration Information and Decision-making) framework, and continuing newer genetics projects to investigate the impact of productions techniques on plant materials and restoration treatments on native plant communities. These activities were supported by two biological science technicians. The effects of the SARS-CoV-2 pandemic were less visible in FY22, allowing SBSC to catch up on backlogged laboratory work. The overall progress of SBSC’s research remains on track with respect to the 5-year plan. While Dr. Rob Massatti was the only scientist supported by the SBSC-CPNPP agreement in FY22, other scientists, including Drs. John Bradford, Seth Munson, Mike Duniway, Sasha Reed, and Daniel Winkler, spent a considerable amount of time providing expertise and support for individual projects. Work activities performed in support of each 5-year plan goal are discussed in turn.

Colorado Plateau↗
USGS2006

Globally synchronous ice core volcanic tracers and abrupt cooling during the last glacial period

We perform a Monte Carlo pattern recognition analysis of the coincidence between three regional volcanic histories from ice coring of Greenland and Antarctica over the period 2 to 45 ka, using SO4 anomalies in Greenland and East Antarctica determined by continuous core chemistry, together with West Antarctic volcanic ash layers determined by remote optical borehole logging and core assays. We find that the Antarctic record of volcanism correlates with Glacial abrupt climate change at a 95% to >99.8% (???3??) significance level and that volcanic depositions at the three locations match at levels exceeding 3??, likely indicating that many common horizons represent single eruptive events which dispersed material world wide. These globally coincident volcanics were associated with abrupt cooling, often simultaneous with onsets or sudden intensifications of millennial cold periods. The striking agreement between sites implies that the consistency of current timescales obtained by isotopic and glaciological dating methods is better than estimated. Copyright 2006 by the American Geogphysical Union.

Journal of Geophysical Research D: Atmospheres↗
USGS1988

The molecular composition of ambers

Bulk (elemental composition, IR, CP/MAS 13 C NMR) and molecular (GC-MS) analyses have been performed on a series of ambers and resins derived from different locations (Dominican Republic, Philippines, Canada, Israel, New Zealand, Chile) having diverse botanical affinities ( Araucariaceae, Hymenaea ) and variable age (from Holocene to Early Cretaceous). No major differences have been observed from the elemental composition and the spectroscopic data; however, the molecular analyses of the solvent extractable fraction show that a specific mixture of components is present in each sample. These are mainly diterpenoid products that in general are also found abundantly in the higher plants from which the ambers and resins originate. Nevertheless, a direct relationship between major terpenoid constituents in fossil resins and precursor plant materials can only be established for the younger samples. Irrespective of the geographical or botanical origin of the ambers and resins, several common age-dependent molecular transformation trends can be recognized: (1) progressive loss of olefinic bonds (especially those located in exocyclic positions), (2) decrease of functionalized products, and (3) increasing proportion of aromatized components. However, even in the samples of older age (Cretaceous) the degree of aromatization is very low when compared with that of other higher-plant related materials such as fossilized woods or low rank coals. This indicates that maturation must involve essentially olefin polymerization processes instead of extensive aromatization.

Organic Geochemistry↗
USGS2002

Lead isotopic analyses of selected soil samples from the USEPA Vasquez Blvd.-I-70 study area, Denver, CO

Large amounts of arsenic contamination, in excess of 2000 ppm, have been found in some residential surface soils in northern Denver, Colorado (USEPA, 1999). Associated with the arsenic are elevated levels of metals such as lead, cadmium and mercury. Potential sources of this contamination include waste from smelters in the area and commercial herbicide containing arsenic trioxide and lead arsenate (USEPA, 1999). As a part of the U.S. Environmental Protection Agency’s Vasquez Boulevard-I-70 Project (VBI70 project; USEPA, 1999), lead isotopic analyses of selected soil samples, smelter waste, and a commercial herbicide and a commercial lead arsenate pesticide have been performed in order to constrain the possible sources of elevated lead, and by proxy arsenic, found in these residential soils. The isotopes of lead can be used as a natural tracer in determining sources of contaminants in soils and stream sediments (e.g. Church and others, 1997; Fey and others, 1999; Unruh and others, 2000). The element lead (Pb) consists of four naturally occurring and stable isotopes, 204Pb, 206Pb, 207Pb, and 208Pb. Three of these, 206Pb, 207Pb, and 208Pb are radiogenic decay products of naturally occurring 238U, 235U, and 232Th, respectively. Owing to variations among the U/Pb and Th/Pb elemental abundance ratios among different types of geologic materials, variations in the relative abundances of the Pb isotopes are produced among different materials during geologic time. In order for the Pb isotope method to be useful for determining possible contaminant sources, two important criteria must be met (e.g. Church and others 1997): (1) It must be possible to obtain and measure the Pb isotopic compositions in all potential contaminant sources and in uncontaminated material and (2) the Pb isotopic compositions of the potential contaminant sources must be distinctly different from one another and from uncontaminated background. Variations among the Pb isotopic ratios in selected samples can be correlated with potential sources of Pb with known isotopic compositions in order to determine the relative contribution of Pb from a specific source to the sample. The purpose of this study is to use Pb isotopic data obtained from a selected subset of samples to determine the Pb isotopic signatures of uncontaminated soils as well as those of potential sources of contamination. The data will eventually be used in conjunction with other geochemical data to help determine which source or sources of contamination are most likely responsible for the elevated arsenic levels in the residential soils.

Colorado↗
USGS2013

Application of the SPARROW model to assess surface-water nutrient conditions and sources in the United States Pacific Northwest

The watershed model SPARROW (Spatially Referenced Regressions on Watershed attributes) was used to estimate mean annual surface-water nutrient conditions (total nitrogen and total phosphorus) and to identify important nutrient sources in catchments of the Pacific Northwest region of the United States for 2002. Model-estimated nutrient yields were generally higher in catchments on the wetter, western side of the Cascade Range than in catchments on the drier, eastern side. The largest source of locally generated total nitrogen stream load in most catchments was runoff from forestland, whereas the largest source of locally generated total phosphorus stream load in most catchments was either geologic material or livestock manure (primarily from grazing livestock). However, the highest total nitrogen and total phosphorus yields were predicted in the relatively small number of catchments where urban sources were the largest contributor to local stream load. Two examples are presented that show how SPARROW results can be applied to large rivers—the relative contribution of different nutrient sources to the total nitrogen load in the Willamette River and the total phosphorus load in the Snake River. The results from this study provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to researchers and water-quality managers performing local nutrient assessments.

Pacific Northwest↗
USGS1980

Experimental study of free-surface flow instability and bedforms in shallow flows.

To test erosion and development of bed sculpture in unstable, pulsating shallow flow, 3 series of experiments were performed in a 10-m flume with flows of Reynolds Number up to 103, Froude Number up to 3.0, and slope up to 2%. In the first, the bed was rigid, in the second and third series planar beds were made from well-sorted and poorly sorted sand, respectively. Development of flow surface instability above the rigid bed showed the following stages: smooth surface; small wavelets; well-developed waves; and rough flow. The second series showed the following sequence: smooth bed; flow-aligned ridge and trough pattern; combined ridge and rhomboid pattern; and rhomboid configuration. The third series demonstrated transverse segregation of the bed material across the ridges.- from Authors

Sedimentary Geology↗
USGS2017

Hydrogeologic and geochemical characterization and evaluation of two arroyos for managed aquifer recharge by surface infiltration in the Pojoaque River Basin, Santa Fe County, New Mexico, 2014–15

In order to provide long-term storage of diverted surface water from the Rio Grande as part of the Aamodt water rights settlement, managed aquifer recharge by surface infiltration in Pojoaque River Basin arroyos was proposed as an option. The initial hydrogeologic and geochemical characterization of two arroyos located within the Pojoaque River Basin was performed in 2014 and 2015 in cooperation with the Bureau of Reclamation to evaluate the potential suitability of these two arroyos as sites for managed aquifer recharge through surface infiltration. The selected reaches were high-gradient (average 3.0–3.5 percent) braided channels filled with unconsolidated sand and gravel-sized deposits that were generally 30–50 feet thick. Saturation was not observed in the unconsolidated channel sands in four subsurface borings but was found at 7–60 feet below the contact between the unconsolidated channel sands and the bedrock. The poorly to well-cemented alluvial deposits that make up the bedrock underlying the unconsolidated channel material is the Tesuque Formation. The individual beds of the Tesuque Formation are reported to be highly heterogeneous and anisotropic, and the bedrock at the site was observed to have variable moisture and large changes in lithology. Surface electrical-resistivity geophysical survey methods showed a sharp contrast between the electrically resistive unconsolidated channel sands and the highly conductive bedrock; however, because of the high conductivity, the resistivity methods were not able to image the water table or preferential flow paths (if they existed) in the bedrock. Infiltration rates measured by double-ring and bulk infiltration tests on a variety of channel morphologies in the study reaches were extremely large (9.7–94.5 feet per day), indicating that the channels could potentially accommodate as much as 6.6 cubic feet per second of applied water without generating surface runoff out of the reach; however, the small volume available for storage in the unconsolidated channel sands (about 410 acre-feet in the east arroyo and about 190 acre-feet in the west arroyo) and the potential for the infiltrating water to preferentially flow over the bedrock contact and out of the reach present a challenge for storing water. Although a detailed assessment of the infiltration rate of the Tesuque Formation is beyond the scope of this investigation, one double-ring infiltrometer test was conducted on an outcrop, resulting in an estimated infiltration rate of about 4 feet per day. The shallow groundwater observed in this investigation was determined to be recharged locally on the basis of groundwater elevations and geochemical and isotopic signatures. The channel sands and shallow bedrock were observed to be weathered, indicating contact with oxic groundwater following deposition. This observation was supported by whole-rock elemental analysis and mineralogy of several core samples. The downward groundwater gradient between the shallow wells and those wells screened at greater depths suggests that the shallow groundwater is recharged by local precipitation and has the potential to migrate to the deeper aquifer units. The two age-dating tracers measured in this investigation, however, demonstrate that the shallow groundwater flow paths are very slow and that the deeper flow paths are likely part of a larger regional system. The composition of the shallow, native groundwater suggests that storing water diverted from the Rio Grande is not likely to leach constituents of concern that would cause the stored water to exceed health-based U.S. Environmental Protection Agency Maximum Contaminant Levels.

New Mexico↗
USGS2019

Sediment monitoring to support modeling a reservoir sediment flush on a sand-bed river in Northern Nebraska

The U.S. Geological Survey (USGS) in cooperation with the U.S. Army Corps of Engineers (USACE), monitored a sediment flush event from Spencer Dam located on the Niobrara River near Spencer, Nebraska, during the fall of 2014. Data collected during the flush was used to validate a one-dimensional sediment transport model developed by the USACE. The USACE surveyed 26 cross sections within the reservoir and as far as 1 kilometer (km) upstream from the reservoir pool to about 10 km downstream from the dam before and after the flushing event to measure erosion and deposition. They also collected surficial sediment samples from sandbars within the reservoir. The USGS assisted USACE in its model validation efforts by collecting sediment data before, during and after the flush using both traditional sampling techniques and a continuous laser-diffraction particle-size analyzer. From the context of longitudinal volumetric change, the model replicated erosion in the upper half of the reservoir within four percent of that observed by survey data and it replicated deposition downstream of the dam within 5 percent. However, the model underpredicted the erosion of the accumulated delta sediments in the reservoir by 43 percent. The timing and magnitude of suspended sediment concentrations produced by the model compared reasonably well to the discrete suspended-sediment sample results. These results indicate cross-sectional survey data and discrete sediment data may be adequate for developing sediment flush models for reservoirs in similar well-sorted sand-bed streams. The USGS installed a continuous particle-size analyzer immediately downstream from the dam. Although the particle-size analyzer was successful in providing a large dataset during the flushing event, based on discrete point samples, it overestimated the amount of fine particles and underrepresented the amount of coarse material. It also required a significant amount of maintenance during the flushing event because of the large sediment load and the rapid bed aggradation. The maintenance issues with the particle-size analyzer along with uncertainty in the correlation to discrete suspended-sediment samples reduced its value for model validation. However, these issues may have been specific to the flushing event at Spencer Dam, which involved a sand-bed dominated stream and a wide channel. It is foreseeable that other sediment flush models developed for different streams with dissimilar sediment gradations may benefit from similar continuous sediment data, but adequate planning and evaluation should be performed.

Nebraska↗