Denitrification potential in stream sediments impacted by acid mine drainage: Effects of pH, various electron donors, and iron
J.L. Baeseman, R. L. Smith, J. Silverstein
2006, Microbial Ecology (51) 232-241
Acid mine drainage (AMD) contaminates thousands of kilometers of stream in the western United States. At the same time, nitrogen loading to many mountain watersheds is increasing because of atmospheric deposition of nitrate and increased human use. Relatively little is known about nitrogen cycling in acidic, heavy-metal-laden streams; however,...
Influence of propagule flotation longevity and light availability on establishment of introduced mangrove species in Hawai'i
J. A. Allen, K. W. Krauss
2006, Pacific Science (60) 367-376
Although no mangrove species are native to the Hawaiian Archipelago, both Rbizopbora mangle and Bruguiera sexangula were introduced and have become naturalized. Rbizopbora mangle has spread to almost every major Hawaiian island, but B. sexangula has established only on O'ahu, where it was intentionally introduced. To examine the possibility that...
Sampling strategies for volatile organic compounds at three karst springs in Tennessee
S.D. Williams, W.J. Wolfe, J.J. Farmer
2006, Ground Water Monitoring and Remediation (26) 53-62
The influence of different sampling strategies on characterizing volatile organic compound (VOC) concentrations and estimating VOC loads was evaluated at three karst springs in Tennessee. During a 6-month period, water samples for VOC analyses were collected weekly at all three springs and as frequently as every 20 min during storms...
An episode of rapid bedrock channel incision during the last glacial cycle, measured with 10Be
L. Reusser, P. Bierman, M. Pavich, J. Larsen, R. Finkel
2006, American Journal of Science (306) 69-102
We use 10Be to infer when, how fast, and why the Susquehanna River incised through bedrock along the U.S. Atlantic seaboard, one of the world's most prominent and ancient passive margins. Although the rate at which large rivers incise rock is a fundamental control on the development of landscapes, relatively...
Flow and form in rehabilitation of large-river ecosystems: an example from the Lower Missouri River
R. B. Jacobson, D.L. Galat
2006, Geomorphology (77) 249-269
On large, intensively engineered rivers like the Lower Missouri, the template of the physical habitat is determined by the nearly independent interaction of channel form and flow regime. We evaluated the interaction between flow and form by modeling four combinations of modern and historical channel form and modern and historical...
Submarine landslides in the Santa Barbara Channel as potential tsunami sources
H. Gary Greene, L.Y. Murai, P. Watts, N.A. Maher, M. A. Fisher, C.E. Paull, P. Eichhubl
2006, Natural Hazards and Earth System Sciences (6) 63-88
Recent investigations using the Monterey Bay Aquarium Research Institutes (MBARI) Remotely Operated Vehicles (ROVs) "Ventana" and "Tiburon" and interpretation of MBARI's EM 300 30 kHz multibeam bathymetric data show that the northern flank of the Santa Barbara Basin has experienced massive slope failures. Of particular concern is the large (130...
The 'Orsten': more than a Cambrian Konservat-Lagerstätte yielding exceptional preservation
Andreas Maas, Andreas Braun, Xi-Ping Dong, Philip C.J. Donoghue, Klaus J. Muller, Ewa Olempska, John E. Repetski, David J. Siveter, Martin Stein, Dieter Waloszek
2006, Palaeoworld (15) 266-282
In several areas of southern Sweden, limestone nodules, locally called Orsten occur within bituminous alum shales. These shales and nodules were deposited under dysoxic conditions at the bottom of what was most likely a shallow sea during the late Middle to Upper Cambrian (ca. 500 million years ago). Subsequently, the...
Wild bird mortality and West Nile virus surveillance: Biases associated with detection, reporting, and carcass persistence
M.R. Ward, D.E. Stallknecht, J. Willis, M.J. Conroy, W.R. Davidson
2006, Journal of Wildlife Diseases (42) 92-106
Surveillance targeting dead wild birds, in particular American crows (Corvus brachyrhynchos), plays a critical role in West Nile virus (WNV) surveillance in the United States. Using crow decoy surrogates, detection and reporting of crow carcasses within urban and rural environments of DeKalb County, Georgia were assessed for potential biases that...
Annual sediment flux estimates in a tidal strait using surrogate measurements
N. K. Ganju, D. H. Schoellhamer
2006, Estuarine, Coastal and Shelf Science (69) 165-178
Annual suspended-sediment flux estimates through Carquinez Strait (the seaward boundary of Suisun Bay, California) are provided based on surrogate measurements for advective, dispersive, and Stokes drift flux. The surrogates are landward watershed discharge, suspended-sediment concentration at one location in the Strait, and the longitudinal salinity gradient. The first two surrogates...
Cross-shore velocity shear, eddies and heterogeneity in water column properties over fringing coral reefs: West Maui, Hawaii
C. D. Storlazzi, M.A. McManus, J.B. Logan, B.E. McLaughlin
2006, Continental Shelf Research (26) 401-421
A multi-day hydrographic survey cruise was conducted to acquire spatially extensive, but temporally limited, high-resolution, three-dimensional measurements of currents, temperature, salinity and turbidity off West Maui in the summer of 2003 to better understand coastal dynamics along a complex island shoreline with coral reefs. These data complement long-term, high-resolution tide,...
Mixing of shallow and deep groundwater as indicated by the chemistry and age of karstic springs
D. J. Toth, B. G. Katz
2006, Hydrogeology Journal (14) 827-847
Large karstic springs in east-central Florida, USA were studied using multi-tracer and geochemical modeling techniques to better understand groundwater flow paths and mixing of shallow and deep groundwater. Spring water types included Ca-HCO3 (six), Na-Cl (four), and mixed (one). The evolution of water chemistry for Ca-HCO3 spring waters was modeled...
Contact zone permeability at intrusion boundaries: New results from hydraulic testing and geophysical logging in the Newark Rift Basin, New York, USA
J.M. Matter, D.S. Goldberg, R. H. Morin, M. Stute
2006, Hydrogeology Journal (14) 689-699
Hydraulic tests and geophysical logging performed in the Palisades sill and the underlying sedimentary rocks in the NE part of the Newark Rift Basin, New York, USA, confirm that the particular transmissive zones are localized within the dolerite-sedimentary rock contact zone and within a narrow interval below this contact...
Estimates of in situ gas hydrate concentration from resistivity monitoring of gas hydrate bearing sediments during temperature equilibration
M. Riedel, P.E. Long, T. S. Collett
2006, Marine Geology (227) 215-225
As part of Ocean Drilling Program Leg 204 at southern Hydrate Ridge off Oregon we have monitored changes in sediment electrical resistivity during controlled gas hydrate dissociation experiments. Two cores were used, each filled with gas hydrate bearing sediments (predominantly mud/silty mud). One core was from Site 1249 (1249F-9H3), 42.1...
Demography, genetics, and the value of mixed messages
John M. Pearce, Sandra L. Talbot
2006, Condor (108) 474-479
Iverson et al. (2004) used estimates of the homing rate for molting adult Harlequin Ducks (Histrionicus histrionicus) in Alaska to draw inferences about population structure. Homing rates, defined as one minus the ratio of birds recaptured elsewhere to those recaptured at the original banding site, were high (0.95–1.00) for males...
Numerical modeling of a long-term in situ chemical osmosis experiment in the Pierre Shale, South Dakota
A.M. Garavito, H. Kooi, C. E. Neuzil
2006, Advances in Water Resources (29) 481-492
We have numerically modeled evolving fluid pressures and concentrations from a nine-year in situ osmosis experiment in the Pierre Shale, South Dakota. These data were obtained and recently interpreted by one of us (C.E.N.) as indicating a potentially significant role for chemical osmosis in media like the Pierre Shale. That...
Perchlorate in pleistocene and holocene groundwater in North-Central New Mexico
Niel Plummer, J.K. Böhlke, M. W. Doughten
2006, Environmental Science & Technology (40) 1757-1763
Groundwater from remote parts of the Middle Rio Grande Basin in north-central New Mexico has perchlorate (ClO4-) concentrations of 0.12−1.8 μg/L. Because the water samples are mostly preanthropogenic in age (0−28 000 years) and there are no industrial sources in the study area, a natural source of the...
A new species of freshwater mussel (Bivalvia: Unionidae), Pleurobema athearni, from the Coosa River Drainage of Alabama, USA
M.M. Gangloff, J.D. Williams, J.W. Feminella
2006, Zootaxa 43-56
The Mobile Basin historically supported one of the most diverse freshwater mussel (Bivalvia: Unionidae) assemblages in North America. More than 65 species of mussels are known from the Basin, but it is difficult to determine how many species were present historically. The drainage's unique physical habitat was largely destroyed between...
Magnesium compounds
D.A. Kramer
2006, Mining Engineering (58) 44-45
In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to...
Design and application of an electromagnetic vibrator seismic source
S.S. Haines
2006, Journal of Environmental & Engineering Geophysics (11) 9-15
Vibrational seismic sources frequently provide a higher-frequency seismic wavelet (and therefore better resolution) than other sources, and can provide a superior signal-to-noise ratio in many settings. However, they are often prohibitively expensive for lower-budget shallow surveys. In order to address this problem, I designed and built a simple but effective...
Probabilistic analysis of tsunami hazards
E.L. Geist, T. Parsons
2006, Natural Hazards (37) 277-314
Determining the likelihood of a disaster is a key component of any comprehensive hazard assessment. This is particularly true for tsunamis, even though most tsunami hazard assessments have in the past relied on scenario or deterministic type models. We discuss probabilistic tsunami hazard analysis (PTHA) from the standpoint of integrating...
Estimating hydraulic properties using a moving-model approach and multiple aquifer tests
K. J. Halford, D. Yobbi
2006, Ground Water (44) 284-291
A new method was developed for characterizing geohydrologic columns that extended >600 m deep at sites with as many as six discrete aquifers. This method was applied at 12 sites within the Southwest Florida Water Management District. Sites typically were equipped with multiple production wells, one for each aquifer and...
The quest for the perfect gravity anomaly: Part 1 - New calculation standards
X. Li, T.G. Hildenbrand, W. J. Hinze, Gordon R. Keller, D. Ravat, M. Webring
2006, SEG Technical Program Expanded Abstracts (25) 859-863
The North American gravity database together with databases from Canada, Mexico, and the United States are being revised to improve their coverage, versatility, and accuracy. An important part of this effort is revision of procedures and standards for calculating gravity anomalies taking into account our enhanced computational power, modern satellite-based...
Industrial garnet
D.W. Olson
2006, Mining Engineering (58) 37
In 2005, US production of crude garnet concentrate for industrial use was 28.4 kt valued at $3.05 million. Refined garnet material sold or used was 30.4 kt valued at $10 million. For the year, the US was one of the world's leading consumers of industrial garnet. Domestic values for crude...
Importance of recent shifts in soil thermal dynamics on growing season length, productivity, and carbon sequestration in terrestrial high-latitude ecosystems
E.S. Euskirchen, A. D. McGuire, D. W. Kicklighter, Q. Zhuang, Joy S. Clein, R.J. Dargaville, D.G. Dye, J.S. Kimball, K.C. McDonald, J. M. Melillo, V.E. Romanovsky, N.V. Smith
2006, Global Change Biology (12) 731-750
In terrestrial high-latitude regions, observations indicate recent changes in snow cover, permafrost, and soil freeze-thaw transitions due to climate change. These modifications may result in temporal shifts in the growing season and the associated rates of terrestrial productivity. Changes in productivity will influence the ability of these ecosystems to sequester...
Spirit rover localization and topographic mapping at the landing site of Gusev crater, Mars
Rongxing Li, Brent A. Archinal, Raymond E. Arvidson, Jim Bell, Phillip R. Christensen, Larry S. Crumpler, David J. Des Marais, Kaichang Di, Tom Duxbury, Matthew P. Golombek, John Grant, Ronald Greeley, Joe Guinn, Aaron H. Johnson, Randolph L. Kirk, Mark Maimone, Larry H. Matthies, Michael Malin, Timothy Parker, Michael H. Sims, Shane D. Thompson, Steven W. Squyres, Laurence A. Soderblom
2006, Journal of Geophysical Research E: Planets (111)
By sol 440, the Spirit rover has traversed a distance of 3.76 km (actual distance traveled instead of odometry). Localization of the lander and the rover along the traverse has been successfully performed at the Gusev crater landing site. We localized the lander in the Gusev crater using two-way Doppler...
