Dinocyst taphonomy, impact craters, cyst ghosts, and the Paleocene-Eocene thermal maximum (PETM)
Lucy E. Edwards
2012, Palynology (36) 80-95
Dinocysts recovered from sediments related to the Chesapeake Bay impact structure in Virginia and the earliest Eocene suboxic environment in Maryland show strange and intriguing details of preservation. Features such as curled processes, opaque debris, breakage, microborings and cyst ghosts, among others, invite speculation about catastrophic depositional processes, rapid burial...
Gemstones
D.W. Olson
2012, Mining Engineering (64) 54-55
The estimated value of natural gemstones produced from U.S. deposits during 2011 was $10.6 million, a 6-percent increase from 2010. U.S. gemstone production included agate, amber, beryl, coral, garnet, jade, jasper, opal, pearl, quartz, sapphire, shell, topaz, tourmaline, turquoise and many other gem materials....
Estimating aboveground biomass in interior Alaska with Landsat data and field measurements
Lei Ji, Bruce K. Wylie, Dana R. Nossov, Birgit E. Peterson, Mark P. Waldrop, Jack W. McFarland, Jennifer R. Rover, Teresa N. Hollingsworth
2012, International Journal of Applied Earth Observation and Geoinformation (18) 451-461
Terrestrial plant biomass is a key biophysical parameter required for understanding ecological systems in Alaska. An accurate estimation of biomass at a regional scale provides an important data input for ecological modeling in this region. In this study, we created an aboveground biomass (AGB) map at 30-m resolution for the...
Evaluation of nature-like and technical fishways for the passage of alewives at two coastal streams in New England
Abigail E. Franklin, Alex Haro, Theodore R. Castro-Santos, John Noreika
2012, Transactions of the American Fisheries Society (141) 624-637
Nature-like fishways have been designed with the intent to reconnect river corridors and provide passage for all species occurring in a system. The approach is gaining popularity both in Europe and North America, but performance of these designs has not been quantitatively evaluated in a field setting for any North...
Magnesium compounds
D.A. Kramer
2012, Mining Engineering (64) 73-74
Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in...
Carbon dioxide stripping in aquaculture -- part III: model verification
John Colt, Barnaby Watten, Tim Pfeiffer
2012, Aquacultural Engineering (47) 47-59
Based on conventional mass transfer models developed for oxygen, the use of the non-linear ASCE method, 2-point method, and one parameter linear-regression method were evaluated for carbon dioxide stripping data. For values of KLaCO2 < approximately 1.5/h, the 2-point or ASCE method are a good fit to experimental data, but...
A half-million-year record of paleoclimate from the Lake Manix Core, Mojave Desert, California
Marith C. Reheis, Jordon Bright, Steve P. Lund, David M. Miller, Gary Skipp, Robert J. Fleck
2012, Palaeogeography, Palaeoclimatology, Palaeoecology (365-366) 11-37
Pluvial lakes in the southwestern U.S. responded sensitively to past climate through effects on rainfall, runoff, and evaporation. Although most studies agree that pluvial lakes in the southwestern U.S. reached their highest levels coeval with glacial stages, the specific timing of increased effective moisture and lake-level rise is debated, particularly...
Current and potential sustainable corn stover feedstock for biofuel production in the United States
Zhengxi Tan, Shu-Guang Liu, Larry L. Tieszen, Norman Bliss
2012, Biomass and Bioenergy (47) 372-386
Increased demand for corn (Zea mays L.) stover as a feedstock for cellulosic ethanol raises concerns about agricultural sustainability. Excessive corn stover harvesting could have long-term impacts on soil quality. We estimated current and future stover production and evaluated the potential harvestable stover amount (HSA) that could be used for biofuel...
Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta
David H. Schoellhamer, Scott Wright, Judith Z. Drexler
2012, San Francisco Estuary and Watershed Science (10)
Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local...
Annual accumulation over the Greenland ice sheet interpolated from historical and newly compiled observation data
Dayong Shen, Yuling Liu, Shengli Huang
2012, Geografiska Annaler, Series A: Physical Geography (94) 377-393
The estimation of ice/snow accumulation is of great significance in quantifying the mass balance of ice sheets and variation in water resources. Improving the accuracy and reducing uncertainty has been a challenge for the estimation of annual accumulation over the Greenland ice sheet. In this study, we kriged and analyzed...
Low genetic diversity and minimal population substructure in the endangered Florida manatee: implications for conservation
Kimberly Pause Tucker, Margaret E. Hunter, Robert K. Bonde, James D. Austin, Ann Marie Clark, Cathy A. Beck, Peter M. McGuire, Madan K. Oli
2012, Journal of Mammalogy (93) 1504-1511
Species of management concern that have been affected by human activities typically are characterized by low genetic diversity, which can adversely affect their ability to adapt to environmental changes. We used 18 microsatellite markers to genotype 362 Florida manatees (Trichechus manatus latirostris), and investigated genetic diversity, population structure, and estimated...
Ages of pre-rift basement and synrift rocks along the conjugate rift and transform margins of the Argintine Precordillera and Laurentia
William A. Thomas, Robert D. Tucker, Ricardo A. Astini, Rodger E. Denison
2012, Geosphere (8) 1366-1383
New geochronologic data from basement rocks support the interpretation that the Argentine Precordillera (Cuyania) terrane was rifted from the Ouachita embayment of the Iapetan margin of Laurentia. New data from the Ozark dome show a range of ages in two groups at 1466 ± 3 to 1462 ± 1 Ma...
Industrial sand and gravel
T.P. Dolley
2012, Mining Engineering (64) 65-65
Domestic production of industrial sand and gravel in 2011 was about 30 Mt (33 million st), increasing slightly compared with 2010. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications....
Perlite
W. Bolen
2012, Mining Engineering (64) 80-81
Domestic production, consumption, exports and prices of perlite in the United States were all estimated to have decreased in 2011 compared with 2010, but not significantly. The weak economic conditions that prevailed in the United States for most of the 2011 probably accounted for these decreases. The only statistic that...
Improving PAGER's real-time earthquake casualty and loss estimation toolkit: a challenge
K. S. Jaiswal, D.J. Wald
2012, Conference Paper, The 15th World Conference on Earthquake Engineering: September 24-28, 2012, Lisbon, Portugal
We describe the on-going developments of PAGER’s loss estimation models, and discuss value-added web content that can be generated related to exposure, damage and loss outputs for a variety of PAGER users. These developments include identifying vulnerable building types in any given area, estimating earthquake-induced damage and loss statistics by...
Post-fire land treatments and wind erosion -- lessons from the Milford Flat Fire, UT, USA
Mark E. Miller, Matthew A. Bowker, Richard L. Reynolds, Harland L. Goldstein
2012, Aeolian Research (7) 29-44
We monitored sediment flux at 25 plots located at the northern end of the 2007 Milford Flat Fire (Lake Bonneville Basin, west-central Utah) to examine the effectiveness of post-fire rehabilitation treatments in mitigating risks of wind erosion during the first 3 years post fire. Maximum values were recorded during Mar–Jul...
Impact-based earthquake alerts with the U.S. Geological Survey's PAGER system: what's next?
D.J. Wald, K. S. Jaiswal, K. D. Marano, D. Garcia, E. So, M. Hearne
2012, Conference Paper, The 15th World Conference on Earthquake Engineering: September 24-28, 2012, Lisbon, Portugal
In September 2010, the USGS began publicly releasing earthquake alerts for significant earthquakes around the globe based on estimates of potential casualties and economic losses with its Prompt Assessment of Global Earthquakes for Response (PAGER) system. These estimates significantly enhanced the utility of the USGS PAGER system which had been,...
Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry
Caixiang Zhang, Robert P. Eganhouse, James Pontolillo, Isabelle M. Cozzarelli, Yanxin Wang
2012, Journal of Chromatography A (1230) 110-116
4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method...
Kinetics of uncatalyzed thermochemical sulfate reduction by sulfur-free paraffin
Tongwei Zhang, Geoffrey S. Ellis, Qisheng Ma, Alon Amrani, Yongchun Tang
2012, Geochimica et Cosmochimica Acta (96) 1-17
To determine kinetic parameters of sulfate reduction by hydrocarbons (HC) without the initial presence of low valence sulfur, we carried out a series of isothermal gold-tube hydrous-pyrolysis experiments at 320, 340, and 360 °C under a constant confined pressure of 24.1 MPa. The reactants used consisted of saturated HC (sulfur-free)...
Identifying potential areas for biofuel production and evaluating the environmental effects: a case study of the James River Basin in the Midwestern United States
Yiping Wu, Shu-Guang Liu, Zhengpeng Li
2012, GCB Bioenergy (4) 875-888
Biofuels are now an important resource in the United States because of the Energy Independence and Security Act of 2007. Both increased corn growth for ethanol production and perennial dedicated energy crop growth for cellulosic feedstocks are potential sources to meet the rising demand for biofuels. However, these measures may...
Hydrogeomorphology of the hyporheic zone: stream solute and fine particle interactions with a dynamic streambed
J. W. Harvey, J.D. Drummond, R.L. Martin, L.E. McPhillips, A.I. Packman, D.J. Jerolmack, S.H. Stonedahl, A.F. Aubeneau, A.H. Sawyer, L. G. Larsen, C.R. Tobias
2012, Journal of Geophysical Research: Biogeosciences (117)
Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 μm...
Interdisciplinary research produces results in understanding planetary dunes
Timothy N. Titus, Rosalyn K. Hayward, Cynthia L. Dinwiddie
2012, Eos, Transactions, American Geophysical Union (93) 367-367
Third International Planetary Dunes Workshop: Remote Sensing and Image Analysis of Planetary Dunes; Flagstaff, Arizona, 12–16 June 2012. This workshop, the third in a biennial series, was convened as a means of bringing together terrestrial and planetary researchers from diverse backgrounds with the goal of fostering collaborative interdisciplinary research. The...
Nearshore hydrodynamics as loading and forcing factors for Escherichia coli contamination at an embayed beach
Zhongfu Ge, Richard L. Whitman, Meredith B. Nevers, Mantha S. Phanikumar, Muruleedhara N. Byappanahalli
2012, Limnology and Oceanography (57) 362-381
Numerical simulations of the transport and fate of Escherichia coli were conducted at Chicago's 63rd Street Beach, an embayed beach that had the highest mean E. coli concentration among 23 similar Lake Michigan beaches during summer months of 2000-2005, in order to find the cause for the high bacterial contamination....
Mapping critical loads of nitrogen deposition for aquatic ecosystems in the Rocky Mountains, USA
Leora Nanus, David W. Clow, Jasmine E. Saros, Verlin C. Stephens, Donald H. Campbell
2012, Environmental Pollution (166) 125-135
Spatially explicit estimates of critical loads of nitrogen (N) deposition (CLNdep) for nutrient enrichment in aquatic ecosystems were developed for the Rocky Mountains, USA, using a geostatistical approach. The lowest CLNdep estimates (−1 yr−1) occurred in high-elevation basins with steep slopes, sparse vegetation, and abundance...
Multiple functions of a multi-component mating pheromone in sea lamprey Petromyzon marinus
N.S. Johnson, S.-S. Yun, T.J. Buchinger, W. Li
2012, Journal of Fish Biology (80) 538-554
The role of the C24 sulphate in the mating pheromone component, 7α,12α,24-trihydroxy-5α-cholan-3-one 24-sulphate (3kPZS), to specifically induce upstream movement in ovulated female sea lampreys Petromyzon marinus was investigated. 7α,12α-dihydroxy-5α-cholan-3-one 24-oic acid (3kACA), a structurally similar bile acid released by spermiated males, but lacking the C24 sulphate ester, was tested in...
