SEARCH · USGS Science

Results for “Applied Energy”

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

SourceResearch connectionFrom yearThrough year

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

At least 361 records · Page 20Linked to original sources

USGS2024

Quantifying potential effects of China’s gallium and germanium export restrictions on the U.S. economy

China’s export controls on gallium and germanium exemplify concerns regarding the reliability of supplies of mineral commodities that are essential to economic development, national security, and transition to renewable energy. This report presents a new model that quantifies the potential effects of mineral commodity supply disruptions on the U.S. economy. After calculating postdisruption equilibrium prices and quantities, a nonlinear optimization routine was used along with economic input-output tables to estimate the effects of varying Chinese net export restrictions of gallium and germanium on U.S. gross domestic product (GDP). The results indicated that a complete restriction of China’s net exports of gallium and germanium could cause the U.S. GDP to decrease by $3.1 billion (with lower and upper estimates of $1.7 billion to $8.2 billion) and $0.4 billion ($0.01 billion to $1.1 billion), respectively, if disrupted separately, and $3.4 billion ($1.7 billion to $9.0 billion) if disrupted simultaneously. The proposed model can be applied to other commodities and disruption scenarios.

Open-File Report↗

USGS2025

Land change, fire, and climate weaken carbon sink in the conterminous U.S.

The land carbon sink of the conterminous United States was evaluated using a bottom-up modeling framework and 30-meter land change data from 1985 to 2020. This cross-scale, cross-landscape, and cross-system approach tracked fractional land cover changes and applied regional model calibration. Results show average terrestrial and aquatic carbon sinks of +110 ± 37 and +19 ± 0.5 teragrams of carbon per year, respectively. The terrestrial carbon sink, showing no clear trend, peaked in the 1990s, with more years as a carbon source since 2000, contradicting recent national and global studies. Land change had the largest impact (−70 ± 5.5 teragrams of carbon per year), exceeding impacts of climate (−33 ± 48 teragrams of carbon per year), wildfire (−7.7 ± 2.4 teragrams of carbon per year), and erosion transport (−1.9 ± 0.13 teragrams of carbon per year). The positive CO2 fertilization effect (+69 ± 12 teragrams of carbon per year) was insufficient to maintain the carbon sink strength. Our framework reveals key paths of carbon loss, with implications for carbon budget and energy policies in the United States and beyond.

conterminous United States↗

USGS1995

Fe(III) and S0 reduction by Pelobacter carbinolicus

There is a close phylogenetic relationship between Pelobacter species and members of the genera Desulfuromonas and Geobacter , and yet there has been a perplexing lack of physiological similarities. Pelobacter species have been considered to have a fermentative metabolism. In contrast, Desulfuromonas and Geobacter species have a respiratory metabolism with Fe(III) serving as the common terminal electron acceptor in all species. However, the ability of Pelobacter species to reduce Fe(III) had not been previously evaluated. When a culture of Pelobacter carbinolicus that had grown by fermentation of 2,3- butanediol was inoculated into the same medium supplemented with Fe(III), the Fe(III) was reduced. There was less accumulation of ethanol and more production of acetate in the presence of Fe(III). P. carbinolicus grew with ethanol as the sole electron donor and Fe(III) as the sole electron acceptor. Ethanol was metabolized to acetate. Growth was also possible on Fe(III) with the oxidation of propanol to propionate or butanol to butyrate if acetate was provided as a carbon source. P. carbinolicus appears capable of conserving energy to support growth from Fe(III) respiration as it also grew with H 2 or formate as the electron donor and Fe(III) as the electron acceptor. Once adapted to Fe(III) reduction, P. carbinolicus could also grow on ethanol or H 2 with S 0 as the electron acceptor. P. carbinolicus did not contain detectable concentrations of the c -type cytochromes that previous studies have suggested are involved in electron transport to Fe(III) in other organisms that conserve energy to support growth from Fe(III) reduction. These results demonstrate that P. carbinolicus may survive in some sediments as an Fe(III) or S 0 reducer rather than growing fermentatively on rare substrates or syntrophically as an ethanol-oxidizing acetogen. These studies also suggest that the ability to use Fe(III) as a terminal electron acceptor may be an important unifying feature of the Geobacter-Desulfuromonas- Pelobacter branch of the delta Proteobacteria .

Applied and Environmental Microbiology↗

USGS2001

Ground-water discharge determined from estimates of evapotranspiration, Death Valley regional flow system, Nevada and California

The Death Valley regional flow system (DVRFS) is one of the larger ground-water flow systems in the southwestern United States and includes much of southern Nevada and the Death Valley region of eastern California. Centrally located within the ground-water flow system is the Nevada Test Site (NTS). The NTS, a large tract covering about 1,375 square miles, historically has been used for testing nuclear devices and currently is being studied as a potential repository for the long-term storage of high-level nuclear waste generated in the United States. The U.S. Department of Energy, as mandated by Federal and State regulators, is evaluating the risk associated with contaminants that have been or may be introduced into the subsurface as a consequence of any past or future activities at the NTS. Because subsurface contaminants can be transported away from the NTS by ground water, components of the ground-water budget are of great interest. One such component is regional ground-water discharge. Most of the ground water leaving the DVRFS is limited to local areas where geologic and hydrologic conditions force ground water upward toward the surface to discharge at springs and seeps. Available estimates of ground-water discharge are based primarily on early work done as part of regional reconnaissance studies. These early efforts covered large, geologically complex areas and often applied substantially different techniques to estimate ground-water discharge. This report describes the results of a study that provides more consistent, accurate, and scientifically defensible measures of regional ground-water losses from each of the major discharge areas of the DVRFS. Estimates of ground-water discharge presented in this report are based on a rigorous quantification of local evapotranspiration (ET). The study identifies areas of ongoing ground-water ET, delineates different ET areas based on similarities in vegetation and soil-moisture conditions, and determines an ET rate for each delineated area. Each area, referred to as an ET unit, generally consists of one or more assemblages of local phreatophytes or a unique moist soil environment. Ten ET units are identified throughout the DVRFS based on differences in spectral-reflectance characteristics. Spectral differences are determined from satellite imagery acquired June 21, 1989, and June 13, 1992. The units identified include areas of open playa, moist bare soils, sparse to dense vegetation, and open water. ET rates estimated for each ET unit range from a few tenths of a foot per year for open playa to nearly 9 feet per year for open water. Mean annual ET estimates are computed for each discharge area by summing estimates of annual ET from each ET unit within a discharge area. The estimate of annual ET from each ET unit is computed as the product of an ET unit's acreage and estimated ET rate. Estimates of mean annual ET range from 450 acre-feet in the Franklin Well area to 30,000 acre-feet in Sarcobatus Flat. Ground-water discharge is estimated as annual ET minus that part of ET attributed to local precipitation. Mean annual ground-water discharge estimates range from 350 acre-feet in the Franklin Well area to 18,000 acre-feet in Ash Meadows. Generally, these estimates are greater for the northern discharge areas (Sarcobatus Flat and Oasis Valley) and less for the southern discharge areas (Franklin Lake, Shoshone area, and Tecopa/ California Valley area) than those previously reported.

California;Nevada↗

USGS2012

Aspect control of water movement on hillslopes near the rain–snow transition of the Colorado Front Range

In the Colorado Front Range, forested catchments near the rain–snow transition are likely to experience changes in snowmelt delivery and subsurface water transport with climate warming and associated shifts in precipitation patterns. Snowpack dynamics are strongly affected by aspect: Lodgepole pine forested north‐facing slopes develop a seasonal snowpack, whereas Ponderosa pine‐dotted south‐facing slopes experience intermittent snow accumulation throughout winter and spring. We tested the degree to which these contrasting water input patterns cause different near‐surface hydrologic response on north‐facing and south‐facing hillslopes during the snowmelt period. During spring snowmelt, we applied lithium bromide (LiBr) tracer to instrumented plots along a north–south catchment transect. Bromide broke through immediately at 10‐ and 30‐cm depths on the north‐facing slope and was transported out of soil waters within 40 days. On the south‐facing slope, Br − was transported to significant depths only during spring storms and remained above the detection limit throughout the study. Modelling of unsaturated zone hydrologic response using Hydrus‐1D corroborated these aspect‐driven differences in subsurface transport. Our multiple lines of evidence suggest that north‐facing slopes are dominated by connected flow through the soil matrix, whereas south‐facing slope soils experience brief periods of rapid vertical transport following snowmelt events and are drier overall than north‐facing slopes. These differences in hydrologic response were largely a function of energy‐driven differences in water supply, emphasizing the importance of aspect and climate forcing when considering contributions of water and solutes to streamflow in catchments near the snow line.

Colorado↗

USGS2001

Identification of methyl halide-utilizing genes in strain IMB-1, a methyl bromide-utilizing bacterium suggests a high degree of conservation of methyl halide-specific genes in gram-negative bacteria

Strain IMB-1, an aerobic methylotrophic member of the alpha subgroup of the Proteobacteria, can grow with methyl bromide as a sole carbon and energy source. A single cmu gene cluster was identified in IMB-1 that contained six open reading frames: cmuC, cmuA, orf146, paaE, hutI, and partial metF. CmuA from IMB-1 has high sequence homology to the methyltransferase CmuA from Methylobacterium chloromethanicum and Hyphomicrobium chloromethanicum and contains a C-terminal corrinoid-binding motif and an N-terminal methyl-transferase motif. However, cmuB, identified in M. chloromethanicum and H. chloromethanicum, was not detected in IMB-1.

Applied and Environmental Microbiology↗

USGS1999

Multi-year persistence of oil mousse on high energy beaches distant from the Exxon Valdez spill origin

For at least 5 yr after the Exxon Valdez spill, relatively unweathered oil mousse has persisted on the exposed rocky shores of Shelikof Strait 500 km from Prince William Sound, Alaska. Previously it was thought that oil would be rapidly removed from such geomorphic settings by wave action. Oil mousse persists at sites in Katmai National Park and Preserve (NP&P) where it was stranded high in the intertidal zone under a lag of large boulders. These boulders armor the beach, preventing waves from disturbing the substrate and its included oil. Weathering of this stranded mousse has been slight – mousse sampled in 1989, 1992 and 1994 show negligible changes in polynuclear aromatic hydrocarbons compared to 11-day old Exxon Valdez crude. The preservation of this oil is due to its transport as mousse boli whose interiors largely escape weathering, followed by its sheltering in the interstices of boulder-armored beaches. The transport of mousse may allow for the long distance dispersal of less weathered, and hence still toxic oil. Our findings suggest that the low ecological sensitivity ratings previously applied to exposed, rocky shorelines need to be modified. The biological threat posed by oil stranded on the Katmai NP&P coast probably is slight because of its small amount and sequestered state. However, it still possesses the ability to be chemically toxic and could be released through disturbance of the armoring boulders by unusually high wave events.

Alaska↗

USGS2002

Variability of suspended-sediment concentration at tidal to annual time scales in San Francisco Bay, USA

Singular spectrum analysis for time series with missing data (SSAM) was used to reconstruct components of a 6-yr time series of suspended-sediment concentration (SSC) from San Francisco Bay. Data were collected every 15 min and the time series contained missing values that primarily were due to sensor fouling. SSAM was applied in a sequential manner to calculate reconstructed components with time scales of variability that ranged from tidal to annual. Physical processes that controlled SSC and their contribution to the total variance of SSC were (1) diurnal, semidiurnal, and other higher frequency tidal constituents (24%), (2) semimonthly tidal cycles (21%), (3) monthly tidal cycles (19%), (4) semiannual tidal cycles (12%), and (5) annual pulses of sediment caused by freshwater inflow, deposition, and subsequent wind-wave resuspension (13%). Of the total variance 89% was explained and subtidal variability (65%) was greater than tidal variability (24%). Processes at subtidal time scales accounted for more variance of SSC than processes at tidal time scales because sediment accumulated in the water column and the supply of easily erodible bed sediment increased during periods of increased subtidal energy. This large range of time scales that each contained significant variability of SSC and associated contaminants can confound design of sampling programs and interpretation of resulting data.

Conference Paper↗

USGS1995

Waterbird predation on fish in western Lake Erie: a bioenergetics model application

To better understand the role of piscivorous waterbirds in the food web of western Lake Erie, we applied a bioenergetics model to determine their total fish consumption, The important nesting species included the Herring Gull (Larus argentatus), Ring-billed Gull (L. delawarensis), Double-crested Cormorant (Phalacrocorax auritus), Great Blue Heron (Ardea herodias), Black-crowned Night-Heron (Nycticorax nycticorax), and Great Egret (Casmerodius albus). The impact of migrant waterbirds, including the Red-breasted Merganser (Mergus serrator), on western Lake Erie fish biomass was also considered in the analysis. According to the modeling results, during the early 1990s, piscivorous waterbirds consumed 13,368 tonnes of fish from western Lake Erie each year. This tonnage was equivalent to 15.2% of the prey fish biomass needed to support the walleye (Stizostedion vitreum) population in western Lake Erie during a single growing season. The model application was useful in quantifying energy flow between birds and fish in a large lake ecosystem.

Condor↗

USGS2015

Potential for real‐time understanding of coupled hydrologic and biogeochemical processes in stream ecosystems: Future integration of telemetered data with process models for glacial meltwater streams

While continuous monitoring of streamflow and temperature has been common for some time, there is great potential to expand continuous monitoring to include water quality parameters such as nutrients, turbidity, oxygen, and dissolved organic material. In many systems, distinguishing between watershed and stream ecosystem controls can be challenging. The usefulness of such monitoring can be enhanced by the application of quantitative models to interpret observed patterns in real time. Examples are discussed primarily from the glacial meltwater streams of the McMurdo Dry Valleys, Antarctica. Although the Dry Valley landscape is barren of plants, many streams harbor thriving cyanobacterial mats. Whereas a daily cycle of streamflow is controlled by the surface energy balance on the glaciers and the temporal pattern of solar exposure, the daily signal for biogeochemical processes controlling water quality is generated along the stream. These features result in an excellent outdoor laboratory for investigating fundamental ecosystem process and the development and validation of process‐based models. As part of the McMurdo Dry Valleys Long‐Term Ecological Research project, we have conducted field experiments and developed coupled biogeochemical transport models for the role of hyporheic exchange in controlling weathering reactions, microbial nitrogen cycling, and stream temperature regulation. We have adapted modeling approaches from sediment transport to understand mobilization of stream biomass with increasing flows. These models help to elucidate the role of in‐stream processes in systems where watershed processes also contribute to observed patterns, and may serve as a test case for applying real‐time stream ecosystem models.

Water Resources Research↗

USGS2021

Lipidomics reveals specific lipid molecules associated with cold stress syndrome in the Florida manatee (Trichechus manatus latirostris)

Cold stress syndrome (CSS) in the Florida manatee ( Trichechus manatus latirostris) results in perturbations to many physiological pathways, often leading to further illness or death. In this study, we applied a non-targeted lipidomics approach with ultra-high performance liquid chromatography and high-resolution tandem mass spectrometry to characterize changes related to CSS in the lipidomic profiles of manatee plasma. Lipidomic analyses were conducted on healthy manatee (control) and cold-exposed manatee plasma samples with varying concentrations of Serum Amyloid A (SAA), an acute-phase protein that is associated with inflammatory disease. Control manatees ( n = 10) were compared to all manatees exposed to cold temperatures ( n = 17), and a subset of those manatees with SAA values > 120 μg/mL ( n = 9). Increased SAA values were associated with higher levels of various acylcarnitine lipids, while several triacylglycerols and oxidized triacylglycerols were significantly lower in manatees with cold exposure. These identified lipids are critical molecules involved in the maintenance of energy homeostasis and could potentially be examined in conjunction with current physical parameters to characterize cold stress. The ability to detect such differences highlights the addition of lipidomics as a valuable tool in understanding cold stress and potentially other illnesses in manatees. Further investigation into the function of the altered lipids could greatly increase our understanding of lipid metabolism in physiologically stressed manatees as well as other marine mammals and inform future management recovery strategies.

Marine Biology↗

USGS2022

Tracking heat in the Willamette River system, Oregon

The Willamette River Basin in northwestern Oregon is home to several cold-water fish species whose habitat has been altered by the Willamette Valley Project, a system of 13 dams and reservoirs operated by the U.S. Army Corps of Engineers. Water-resource managers use a variety of flow- and temperature-management strategies to ameliorate the effects of upstream Willamette Valley Project dams on the habitat and viability of these anadromous and native fish. In this study, new capabilities were added to the CE-QUAL-W2 two-dimensional flow and water-quality model to inform those flow- and temperature-management strategies by tracking the quantities and ages of water and heat from individual upstream sources to downstream locations in the Willamette River system. Specifically, the fraction of water and heat attributable to upstream dam releases or other water inputs, and the fraction of heat sourced from environmental heat fluxes across the water and sediment surfaces, were tracked and quantified in the river at all locations and times simulated by the model. Applying the updated CE-QUAL-W2 models to the Willamette River system for the months of March through October in the years 2011 (cool and wet), 2015 (hot and dry), and 2016 (warm and somewhat dry) demonstrated that the influence of upstream dam releases on downstream water temperature diminished within a few days as water moved downstream. At sites that are roughly two or more days of travel from upstream dams (Albany and downstream), the July–August fraction of riverine heat content that could be tracked back to upstream dam releases typically diminished to less than 20 percent, despite the fact that roughly 50 percent of July–August streamflow could be attributed to upstream dam releases at the same sites. In contrast, the fraction of riverine heat content that could be attributed to environmental energy fluxes continued to increase with downstream distance, from about 59 to 67 percent at Albany during July–August to 62 to 73 percent at Keizer and 68 to 79 percent at Newberg. At locations sufficiently far downstream, upstream dam releases affect water temperature mainly through a decrease in travel time (less time for environmental heat fluxes to warm the river during summer) and an increase in thermal mass (more water to dilute and buffer incoming heat fluxes) rather than through the simple transport of heat content (water temperature) released from the dams. This concept was explored not only for the baseline conditions that occurred in March–October of 2011, 2015, and 2016, but also for a hypothetical high-flow release during August 2016 and an actual high-flow release during August 2017. In these high-flow releases, an extra 2,500 cubic feet per second (roughly) was released from Dexter Dam on the Middle Fork Willamette River, and downstream effects were measured (2017, actual) and simulated (2016, hypothetical). Results of the simulations were consistent with insights gained from the baseline conditions, such that temperature changes caused by flow augmentation were substantial in upstream reaches (measured cooling of about 1.5 °C near Harrisburg [43 miles downstream] and Albany [84 miles downstream] in 2017, and cooling of about 0.5 °C near Albany in 2016) and diminished farther downstream, but still measurable (more than a few tenths of a degree Celsius) even at Newberg, which is about 154 miles downstream. The direct downstream effects of dam releases on the river heat content attributable to those releases were increased by the hypothetical flow augmentation, with increases of 20 percent at Harrisburg and 12 percent at Keizer. Even with a decreased influence of environmental energy fluxes on river heat content, however, the fraction of heat content attributable to such fluxes was still more than 50 percent at and downstream of Albany and more than 70 percent at Newberg, where the river temperature was less affected by upstream dam-release temperatures and instead was affected primarily by a decreased travel time and increased thermal mass.

Oregon↗

USGS2023

When less is more: How increasing the complexity of machine learning strategies for geothermal energy assessments may not lead toward better estimates

Previous moderate- and high-temperature geothermal resource assessments of the western United States utilized data-driven methods and expert decisions to estimate resource favorability. Although expert decisions can add confidence to the modeling process by ensuring reasonable models are employed, expert decisions also introduce human and, thereby, model bias. This bias can present a source of error that reduces the predictive performance of the models and confidence in the resulting resource estimates. Our study aims to develop robust data-driven methods with the goals of reducing bias and improving predictive ability. We present and compare nine favorability maps for geothermal resources in the western United States using data from the U.S. Geological Survey's 2008 geothermal resource assessment. Two favorability maps are created using the expert decision-dependent methods from the 2008 assessment ( i.e., weight-of-evidence and logistic regression). With the same data, we then create six different favorability maps using logistic regression (without underlying expert decisions), XGBoost, and support-vector machines paired with two training strategies. The training strategies are customized to address the inherent challenges of applying machine learning to the geothermal training data, which have no negative examples and severe class imbalance. We also create another favorability map using an artificial neural network. We demonstrate that modern machine learning approaches can improve upon systems built with expert decisions. We also find that XGBoost, a non-linear algorithm, produces greater agreement with the 2008 results than linear logistic regression without expert decisions, because the expert decisions in the 2008 assessment rendered the otherwise linear approaches non-linear despite the fact that the 2008 assessment used only linear methods. The F1 scores for all approaches appear low (F1 score < 0.10), do not improve with increasing model complexity, and, therefore, indicate the fundamental limitations of the input features ( i.e., training data). Until improved feature data are incorporated into the assessment process, simple non-linear algorithms ( e.g., XGBoost) perform equally well or better than more complex methods ( e.g., artificial neural networks) and remain easier to interpret.

Geothermics↗

USGS1965

Fluvial sediment of the Mississippi River at St. Louis, Missouri

An investigation of the fluvial sediment of the Mississippi River at St. Louis, Mo., was begun in 1948. Most data have been obtained only to determine the daily suspended-sediment discharge and the particle-size distribution of suspended sediment and bed material, but a few data have been obtained to study the flow resistance, the vertical distribution of sediment and velocity, and the bed-material discharge. The flow of the Mississippi River at St. Louis is made up of the flows from the Missouri River, which had an average flow of 79,860 cubic feet per second for 1897-1958 at Hermann, Mo., and from the upper Mississippi River, which had an average flow of 91,890 cubic feet per second for 1928-58 at Alton, Il. The Missouri River is partly controlled by reservoirs that had a total capacity of 90,300,000 acre-feet in 1956, and the upper Mississippi River is partly controlled by lakes and reservoirs that had a total capacity of 4,890,000 acre-feet in 1956. The flows of the Missouri and upper Mississippi Rivers have not become mixed at St. Louis; so the river has a lateral gradient of suspended-sediment concentration. The concentration near the west bank has been as much as 2,400 parts per million greater than the concentration near the east bank. Suspended-sediment discharges from April 1948 to September 1958 ranged from 4,250 to 7,010,000 tons per day and averaged 496,000 tons per day. Mean concentrations for water years decreased steadily from 1,690 parts per million in 1949 to 403 parts per million in 1956, but they increased to 756 parts per million in 1958. Effects of new reservoirs in the Missouri River basin on the concentration have been obscured by the close relation of concentration to streamflow. Measured suspended-sediment discharge through September 1958 averaged 47 percent clay, 38 percent silt, and 15 percent sand. Variations of particle size were due mainly to differences in the source areas of the sediment. Most of the bed material in the main flow was between 0.125 and 1.000 millimeter in diameter. The average of median diameters was related to the discharge for periods of 1 year and longer. Geometric quartile deviations of the bed material ranged from 1.1 to 2.5 and averaged 1.5. The mean elevation of the bed had a range of almost 10 feet and was related to the median diameter of bed material by the regression equation hb=363.0 - 7.8 d50 for which the standard error of estimate was 0.91 foot. The resistance to flow as measured by Manning's n ranged from 0.024 to 0.041 and was related to the discharge and mean velocity but not to the shear velocity. Normal dune height is 2-8 feet, and average dune length is about 250 feet. When the resistance to flow was low, much of the bed was fairly fiat; a few dunes were present, but they were much longer than the average. For a given discharge during individual rises in stage, the gage height was lower for increasing discharge than for decreasing discharge even though the bed elevation was higher. The changes in gage height were not caused by changes in energy gradient due to changing discharge, by channel storage between the gage and the measuring section, nor by return of overbank flow; but they were probably caused by a combination of changes in roughness due to changing bed configuration and of changes in turbulence constant due to changing sediment concentration. Turbulence constants (Von Karman's k) computed from velocity measurements at 5-10 points in the vertical and from routine velocity measurements at 2 points in the vertical averaged 0.35 and 0.33, respectively. The exponent z1 of the vertical distribution of concentration for different size ranges varied with about the 0.77 power of the fall velocity. Except for the difference between the theoretical variation and the actual variation of z1 with changing fall velocity, the theoretical equation for the vertical distribution of sediment concentration seems to apply reasonably well for the Miss

Water Supply Paper↗

USGS2011

Evidence and biogeochemical implications for glacially-derived sediments in an active margin cold seep

Delineating sediment organic matter origins and sediment accumulation rates at gas hydratebearing and hydrocarbon seeps is complicated by the microbial transfer of 13C-depleted and 14Cdepleted methane carbon into sedimentary pools. Sediment 13C and 14C measurements from four cores recovered at Bullseye vent on the northern Cascadia margin are used to identify methane carbon assimilation into different carbon pools. While the total organic carbon (TOC) is mostly unaltered and primarily terrigenous in origin, planktonic foraminifera and the bulk carbonate display evidence of methane overprinting. Mass balance models are applied to determine the extent to which methane overprinting increased the radiocarbon ages of the biogenic foraminifera. The corrected and calibrated foraminifera ages between sediment depths of 70 and 573 cm are from 14.9 to 15.9 ka BP, which coincides with the retreat of the late Quaternary Cordilleran Ice Sheet from Vancouver Island. Uniform TOC _13C values of -24.5 ± 0.5&permil; from the upper 8 meters of sediment at Bullseye vent suggest all cored material is Pleistocene-derived glacimarine material deposited as the ice edge retreated landward. Bullseye vent is located within an uplifted sediment block isolated from turbidite deposition and has been a site of non-deposition since the ice sheet retreated from the shelf. Biogeochemical implications of seep sediments being dominated by aged, organic-poor (<0.4 wt% TOC) material are that methane is the primary energy source, and microbes directly and indirectly associated with the anaerobic oxidation of methane (AOM) will dominate the seep microbial community.

Conference Paper↗

USGS2016

Borehole deviation and correction factor data for selected wells in the eastern Snake River Plain aquifer at and near the Idaho National Laboratory, Idaho

The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, has maintained a water-level monitoring program at the Idaho National Laboratory (INL) since 1949. The purpose of the program is to systematically measure and report water-level data to assess the eastern Snake River Plain aquifer and long term changes in groundwater recharge, discharge, movement, and storage. Water-level data are commonly used to generate potentiometric maps and used to infer increases and (or) decreases in the regional groundwater system. Well deviation is one component of water-level data that is often overlooked and is the result of the well construction and the well not being plumb. Depending on measured slant angle, where well deviation generally increases linearly with increasing slant angle, well deviation can suggest artificial anomalies in the water table. To remove the effects of well deviation, the USGS INL Project Office applies a correction factor to water-level data when a well deviation survey indicates a change in the reference elevation of greater than or equal to 0.2 ft. Borehole well deviation survey data were considered for 177 wells completed within the eastern Snake River Plain aquifer, but not all wells had deviation survey data available. As of 2016, USGS INL Project Office database includes: 57 wells with gyroscopic survey data; 100 wells with magnetic deviation survey data; 11 wells with erroneous gyroscopic data that were excluded; and, 68 wells with no deviation survey data available. Of the 57 wells with gyroscopic deviation surveys, correction factors for 16 wells ranged from 0.20 to 6.07 ft and inclination angles (SANG) ranged from 1.6 to 16.0 degrees. Of the 100 wells with magnetic deviation surveys, a correction factor for 21 wells ranged from 0.20 to 5.78 ft and SANG ranged from 1.0 to 13.8 degrees, not including the wells that did not meet the correction factor criteria of greater than or equal to 0.20 ft. Forty-seven wells had gyroscopic and magnetic deviation survey data for the same well. Datasets for both survey types were compared for the same well to determine whether magnetic survey data were consistent with gyroscopic survey data. Of those 47 wells, 96 percent showed similar correction factor estimates (≤ 0.20 ft) for both magnetic and gyroscopic well deviation surveys. A linear comparison of correction factor estimates for both magnetic and gyroscopic deviation well surveys for all 47 wells indicate good linear correlation, represented by an r-squared of 0.88. The correction factor difference between the gyroscopic and magnetic surveys for 45 of 47 wells ranged from 0.00 to 0.18 ft, not including USGS 57 and USGS 125. Wells USGS 57 and USGS 125 show a correction factor difference of 2.16 and 0.36 ft, respectively; however, review of the data files suggest erroneous SANG data for both magnetic deviation well surveys. The difference in magnetic and gyroscopic well deviation SANG measurements, for all wells, ranged from 0.0 to 0.9 degrees. These data indicate good agreement between SANG data measured using the magnetic deviation survey methods and SANG data measured using gyroscopic deviation survey methods, even for surveys collected years apart.

Idaho↗

USGS2023

Leveraging the strengths of citizen science and structured surveys to achieve scalable inference on population size

Population size is a key metric for management and policy decisions, yet wildlife monitoring programmes are often limited by the spatial and temporal scope of surveys. In these cases, citizen science data may provide complementary information at higher resolution and greater extent. We present a case study demonstrating how data from the eBird citizen science programme can be combined with regional monitoring efforts by the US Fish and Wildlife Service to produce high-resolution estimates of golden eagle abundance. We developed a model that uses aerial survey data from the western United States to calibrate high-resolution annual estimates of relative abundance from eBird. Using this model, we compared regional population size estimates based on the calibrated eBird information with those based on aerial survey data alone. Population size estimates based on the calibrated eBird information had strong correspondence to estimates from aerial survey data in two out of four regions, and population trajectories based on the two approaches showed high correlations. We demonstrate how the combination of citizen science data and targeted surveys can be used to (a) increase the spatial resolution of population size estimates, (b) extend the spatial extent of inference and (c) predict population size beyond the temporal period of surveys. Findings based on this case study can be used to refine policy metrics used by the US Fish and Wildlife Service and inform permitting regulations (e.g. mortality/harm associated with wind energy development). Policy implications : Our results demonstrate the ability of citizen science data to complement targeted monitoring programmes and improve the efficacy of decision frameworks that require information on population size or trajectory. After validating citizen science data against survey-based benchmarks, agencies can harness strengths of citizen science data to supplement information needs and increase the resolution and extent of population size predictions.

Journal of Applied Ecology↗

USGS2000

Reevaluation of tsunami formation by debris avalanche at Augustine Volcano, Alaska

Debris avalanches entering the sea at Augustine Volcano, Alaska have been proposed as a mechanism for generating tsunamis. Historical accounts of the 1883 eruption of the volcano describe 6- to 9-meter-high waves that struck the coastline at English Bay (Nanwalek), Alaska about 80 kilometers east of Augustine Island. These accounts are often cited as proof that volcanigenic tsunamis from Augustine Volcano are significant hazards to the coastal zone of lower Cook Inlet. This claim is disputed because deposits of unequivocal tsunami origin are not evident at more than 50 sites along the lower Cook Inlet coastline where they might be preserved. Shallow water (<25 m) around Augustine Island, in the run-out zone for debris avalanches, limits the size of an avalanche-caused wave. If the two most recent debris avalanches, Burr Point (A.D. 1883) and West Island (<500 yr. B.P.) were traveling at velocities in the range of 50 to 100 meters per second, the kinetic energy of the avalanches at the point of impact with the ocean would have been between 1014 and 1015 joules. Although some of this energy would be dissipated through boundary interactions and momentum transfer between the avalanche and the sea, the initial wave should have possessed sufficient kinetic energy to do geomorphic work (erosion, sediment transport, formation of wave-cut features) on the coastline of lowwer Cook Inlet. Because widespread evidence of the effects of large waves cannot be found, it appears that the debris avalanches could not have been traveling very fast when they entered the sea, or they happened during low tide and displaced only small volumes of water. In light of these results, the hazard from volcanigenic tsunamis from Augustine Volcano appears minor, unless a very large debris avalanche occurs at high tide.

Pure and Applied Geophysics↗