Biogeochemical factors affecting the presence of 210Po in groundwater
R. L. Seiler, L.L. Stillings, N. Cutler, L. Salonen, I. Outola
2011, Applied Geochemistry (26) 526-539
The discovery of natural 210Po enrichment at levels exceeding 500 mBq/L in numerous domestic wells in northern Nevada, USA, led to a geochemical investigation of the processes responsible for its mobilization. 210Po activities in 63 domestic and public-supply wells ranged from below 1 mBq/L to 6590 ± 590 mBq/L, among...
Suspended material availability and filtration-biodeposition processes performed by a native and invasive bivalve species in streams
C.L. Atkinson, M.R. First, A.P. Covich, Stephen P. Opsahl, S.W. Golladay
2011, Hydrobiologia (667) 191-204
Unionid mussels are among the most threatened group of freshwater organisms globally. They are known for their ability to filter food particles from flowing and standing waters. However, invasive bivalve species, such as the Asian clam (Corbicula fluminea) in North America, have the potential to overlap in feeding and potentially...
Diurnal trends in methylmercury concentration in a wetland adjacent to Great Salt Lake, Utah, USA
D. L. Naftz, J.R. Cederberg, D. P. Krabbenhoft, K. R. Beisner, J. Whitehead, J. Gardberg
2011, Chemical Geology (283) 78-86
A 24-h field experiment was conducted during July 2008 at a wetland on the eastern shore of Great Salt Lake (GSL) to assess the diurnal cycling of methylmercury (MeHg). Dissolved (< 0.45 μm) MeHg showed a strong diurnal variation with consistently decreasing concentrations during daylight periods and...
Climatic controls on the snowmelt hydrology of the northern Rocky Mountains
Gregory T. Pederson, S.T. Gray, T. Ault, W. Marsh, Daniel B. Fagre, A.G. Bunn, C.A. Woodhouse, L.J. Graumlich
2011, Journal of Climate (24) 1666-1687
The northern Rocky Mountains (NRMs) are a critical headwaters region with the majority of water resources originating from mountain snowpack. Observations showing declines in western U.S. snowpack have implications for water resources and biophysical processes in high-mountain environments. This study investigates oceanic and atmospheric controls underlying changes in timing, variability,...
The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete
W. H. Langer
2011, Earthquake Spectra (27) 505-520
An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significant damage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form...
SPECTRAL data-based estimation of soil heat flux
Ramesh K. Singh, A. Irmak, Elizabeth Walter-Shea, S.B. Verma, A.E. Suyker
2011, Transactions of the ASABE (54) 1589-1597
Numerous existing spectral-based soil heat flux (G) models have shown wide variation in performance for maize and soybean cropping systems in Nebraska, indicating the need for localized calibration and model development. The objectives of this article are to develop a semi-empirical model to estimate G from a normalized difference vegetation...
Brittle and ductile friction and the physics of tectonic tremor
Eric G. Daub, David R. Shelly, Robert A. Guyer, P.A. Johnson
2011, Geophysical Research Letters (38) 1-4
Observations of nonvolcanic tremor provide a unique window into the mechanisms of deformation and failure in the lower crust. At increasing depths, rock deformation gradually transitions from brittle, where earthquakes occur, to ductile, with tremor occurring in the transitional region. The physics of deformation in the transition region remain poorly...
Nekton community response to a large-scale Mississippi River discharge: Examining spatial and temporal response to river management
Bryan P. Piazza, Megan La Peyre
2011, Estuarine, Coastal and Shelf Science (91) 379-387
Freshwater flow is generally held to be one of the most influential factors affecting community structure and production in estuaries. In coastal Louisiana, the Caernarvon Freshwater Diversion (CFD) is managed to control freshwater discharge from the Mississippi River into Breton Sound basin. Operational since 1991, CFD has undergone several changes...
Long-term patterns and short-term dynamics of stream solutes and suspended sediment in a rapidly weathering tropical watershed
James B. Shanley, W. H. McDowell, Robert F. Stallard
2011, Water Resources Research (47)
The 326 ha Río Icacos watershed in the tropical wet forest of the Luquillo Mountains, northeastern Puerto Rico, is underlain by granodiorite bedrock with weathering rates among the highest in the world. We pooled stream chemistry and total suspended sediment (TSS) data sets from three discrete periods: 1983–1987, 1991–1997, and...
The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3
L.J. Donner, B.L. Wyman, R.S. Hemler, L.W. Horowitz, Y. Ming, M. Zhao, J.-C. Golaz, P. Ginoux, S.-J. Lin, M.D. Schwarzkopf, J. Austin, G. Alaka, W.F. Cooke, T.L. Delworth, S.M. Freidenreich, C.T. Gordon, S.M. Griffies, I.M. Held, W.J. Hurlin, S.A. Klein, T.R. Knutson, A.R. Langenhorst, H.-C. Lee, Y. Lin, B.I. Magi, S.L. Malyshev, Paul Milly, V. Naik, M.J. Nath, R. Pincus, J.J. Ploshay, V. Ramaswamy, C.J. Seman, E. Shevliakova, J.J. Sirutis, W.F. Stern, R.J. Stouffer, R.J. Wilson, M. Winton, A.T. Wittenberg, F. Zeng
2011, Journal of Climate (24) 3484-3519
The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. The goal of CM3 is to address emerging issues in climate change, including aerosol–cloud interactions, chemistry–climate interactions, and coupling between the troposphere and stratosphere. The model is also...
Bathymetric controls on Pliocene North Atlantic and Arctic sea surface temperature and deepwater production
Marci M. Robinson, P.J. Valdes, A.M. Haywood, H.J. Dowsett, D.J. Hill, S.M. Jones
2011, Palaeogeography, Palaeoclimatology, Palaeoecology (309) 92-97
The mid-Pliocene warm period (MPWP; ~ 3.3 to 3.0 Ma) is the most recent interval in Earth's history in which global temperatures reached and remained at levels similar to those projected for the near future. The distribution of global warmth, however, was different than today in that the high latitudes warmed more...
Ammonium in thermal waters of Yellowstone National Park: Processes affecting speciation and isotope fractionation
J.M. Holloway, D. Kirk Nordstrom, J.K. Böhlke, R. Blaine McCleskey, J.W. Ball
2011, Geochimica et Cosmochimica Acta (75) 4611-4636
Dissolved inorganic nitrogen, largely in reduced form (NH4(T)≈NH4(aq)++NH3(aq)o), has been documented in thermal waters throughout Yellowstone National Park, with concentrations ranging from a few micromolar along the Firehole River to millimolar concentrations at Washburn Hot Springs. Indirect evidence from rock nitrogen analyses and previous work on organic compounds associated with...
Global patterns of phytoplankton dynamics in coastal ecosystems
H. Paerl, Kedong Yin, J. Cloern, James E. Cloern
2011, Conference Paper, Eos
Scientific Committee on Ocean Research Working Group 137 Meeting; Hangzhou, China, 17-21 October 2010; Phytoplankton biomass and community structure have undergone dramatic changes in coastal ecosystems over the past several decades in response to climate variability and human disturbance. These changes have short- and long-term impacts on global carbon and...
Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer
J.B. Heffernan, A.R. Albertin, M.L. Fork, B. G. Katz, M.J. Cohen
2011, Biogeosciences Discussions (8) 10247-10294
Aquifer denitrification is among the most poorly constrained fluxes in global and regional nitrogen budgets. The few direct measurements of denitrification in groundwaters provide limited information about its spatial and temporal variability, particularly at the scale of whole aquifers. Uncertainty in estimates of denitrification may also lead to underestimates of...
Mid Holocene lake level and shoreline behavior during the Nipissing phase of the upper Great Lakes at Alpena, Michigan, USA
T.A. Thompson, K. Lepper, A.L. Endres, J.W. Johnston, S.J. Baedke, E.P. Argyilan, R.K. Booth, D.A. Wilcox
2011, Journal of Great Lakes Research (37) 567-576
The Nipissing phase was the last pre-modern high-water stage of the upper Great Lakes. Represented as either a one- or two-peak highstand, the Nipissing occurred following a long-term lake-level rise. This transgression was primarily an erosional event with only the final stage of the transgression preserved as barriers, spits, and strandplains...
Probing magnetic bottom and crustal temperature variations along the Red Sea margin of Egypt
D. Ravat, A. Salem, A.M.S. Abdelaziz, E. Elawadi, P. Morgan
2011, Tectonophysics (510) 337-344
Over 50 magnetic bottom depths derived from spectra of magnetic anomalies in Eastern Egypt along the Red Sea margin show variable magnetic bottoms ranging from 10 to 34 km. The deep magnetic bottoms correspond more closely to the Moho depth in the region, and not the depth of 580 °C, which lies...
Human dignity in concept and practice
D.J. Mattson, S.G. Clark
2011, Policy Sciences (44) 303-319
Dignity seems to be something that virtually all people want. It is a seminal expression of the human experience that gains authority through the convergent demands of people worldwide. Even so, the human dignity concept is in unhelpful disarray. Dignity is variously viewed as an antecedent, a consequence, a value,...
Trophic ecology and gill raker morphology of seven catostomid species in Iowa rivers
J.R. Spiegel, M.C. Quist, J.E. Morris
2011, Journal of Applied Ichthyology (27) 1159-1164
Understanding the trophic ecology of closely‐related species is important for providing insight on inter‐specific competition and resource partitioning. Although catostomids often dominate fish assemblages in lotic systems, little research has been conducted on their ecology. This study was developed to provide information on the trophic ecology of catostomids in several...
Measuring currents in submarine canyons: technological and scientific progress in the past 30 years
J. P. Xu
2011, Geosphere (7) 868-876
The development and application of acoustic and optical technologies and of accurate positioning systems in the past 30 years have opened new frontiers in the submarine canyon research communities. This paper reviews several key advancements in both technology and science in the field of currents in submarine canyons since the1979...
Specifying initial stress for dynamic heterogeneous earthquake source models
D.J. Andrews, M. Barall
2011, Bulletin of the Seismological Society of America (101) 2408-2417
Dynamic rupture calculations using heterogeneous stress drop that is random and self-similar with a power-law spatial spectrum have great promise of producing realistic ground-motion predictions. We present procedures to specify initial stress for random events with a target rupture length and target magnitude. The stress function is modified in the...
MercNet: A national monitoring network to assess responses to changing mercury emissions in the United States
D. Schmeltz, D.C. Evers, C. T. Driscoll, R. Artz, M. Cohen, D. Gay, R. Haeuber, D. P. Krabbenhoft, R. Mason, K. Morris, J.G. Wiener
2011, Ecotoxicology (20) 1713-1725
A partnership of federal and state agencies, tribes, industry, and scientists from academic research and environmental organizations is establishing a national, policy-relevant mercury monitoring network, called MercNet, to address key questions concerning changes in anthropogenic mercury emissions and deposition, associated linkages to ecosystem effects, and recovery from mercury contamination. This...
Satellite and ground observations of the June 2009 eruption of Sarychev Peak volcano, Matua Island, Central Kuriles
A. Rybin, M. Chibisova, P. Webley, T. Steensen, P. Izbekov, Christina A. Neal, V. Realmuto
2011, Bulletin of Volcanology (73) 1377-1392
After 33 years of repose, one of the most active volcanoes of the Kurile island arc—Sarychev Peak on Matua Island in the Central Kuriles—erupted violently on June 11, 2009. The eruption lasted 9 days and stands among the largest of recent historical eruptions in the Kurile Island chain. Satellite monitoring of the...
Uranium and barium cycling in a salt wedge subterranean estuary: The influence of tidal pumping
I.R. Santos, W. C. Burnett, S. Misra, I.G.N.A. Suryaputra, J. P. Chanton, T. Dittmar, R.N. Peterson, P.W. Swarzenski
2011, Chemical Geology (287) 114-123
The contribution of submarine groundwater discharge (SGD) to oceanic metal budgets is only beginning to be explored. Here, we demonstrate that biogeochemical processes in a northern Florida subterranean estuary (STE) significantly alter U and Ba concentrations entering the coastal ocean via SGD. Tidal pumping controlled the distribution of dissolved metals...
The dynamics, transmission, and population impacts of avian malaria in native hawaiian birds: A modeling approach
Michael D. Samuel, P.H.F. Hobbelen, F. Decastro, Jorge A. Ahumada, Dennis A. LaPointe, Carter T. Atkinson, Bethany L. Woodworth, P.J. Hart, D.C. Duffy
2011, Ecological Applications (21) 2960-2973
We developed an epidemiological model of avian malaria (Plasmodium relictum) across an altitudinal gradient on the island of Hawaii that includes the dynamics of the host, vector, and parasite. This introduced mosquito‐borne disease is hypothesized to have contributed to extinctions and major shifts in the altitudinal distribution of highly susceptible...
Effects of environmental temperature on the dynamics of ichthyophoniasis in Juvenile Pacific Herring (Clupea pallasii)
J.L. Gregg, Johanna J. Vollenweider, C.A. Grady, R.A. Heintz, P.K. Hershberger
2011, Journal of Parasitology Research (2011)
The effects of temperature and infection by Ichthyophonus were examined in juvenile Pacific herring (Clupea pallasii) maintained under simulated overwinter fasting conditions. In addition to defining parameters for a herring bioenergetics model (discussed in Vollenweider et al. this issue), these experiments provided new insights into factors influencing the infectivity and...
