EXAFS study of mercury(II) sorption to Fe- and Al-(hydr)oxides: I. Effects of pH
C.S. Kim, J. J. Rytuba, Gordon E. Brown Jr.
2004, Journal of Colloid and Interface Science (271) 1-15
The study of mercury sorption products in model systems using appropriate in situ molecular-scale probes can provide detailed information on the modes of sorption at mineral/water interfaces. Such studies are essential for assessing the influence of sorption processes on the transport of Hg in contaminated natural systems. Macroscopic uptake of...
Challenging the assumption of habitat limitation: An example from centrarchid fishes over an intermediate spatial scale
S. Gutreuter
2004, River Research and Applications (20) 413-425
Habitat rehabilitation efforts are predicated on the frequently untested assumption that habitat is limiting to populations. These efforts are typically costly and will be ineffective if habitat is not limiting. Therefore it is important to assess, rather than assume, habitat limitation wherever habitat rehabilitation projects are considered. Catch-count data from...
Mapping recent lava flows at Westdahl Volcano, Alaska, using radar and optical satellite imagery
Z. Lu, Russ Rykhus, Timothy Masterlark, K.G. Dean
2004, Remote Sensing of Environment (91) 345-353
Field mapping of young lava flows at Aleutian volcanoes is logistically difficult, and the utility of optical images from aircraft or satellites for this purpose is greatly reduced by persistent cloud cover. These factors have hampered earlier estimates of the areas and volumes of three young lava flows at Westdahl...
Rehabilitation of a lignite mine-disturbed area in the Indian Desert
K.D. Sharma, P. Kumar, L. P. Gough, J.R. SanFilipo
2004, Land Degradation and Development (15) 163-176
Extensive lignite mining in the Indian (Thar) Desert commenced within the past decade. Accompanying extraction of this valuable resource there have been visible, important environmental impacts. The resultant land degradation has prompted concern from both public and regulatory bodies. This research assesses the success of rehabilitation plans implemented to revegetate...
Thematic accuracy of the 1992 National Land-Cover Data for the western United States
J.D. Wickham, S.V. Stehman, J.H. Smith, L. Yang
2004, Remote Sensing of Environment (91) 452-468
The MultiResolution Land Characteristics (MRLC) consortium sponsored production of the National Land Cover Data (NLCD) for the conterminous United States, using Landsat imagery collected on a target year of 1992 (1992 NLCD). Here we report the thematic accuracy of the 1992 NLCD for the six western mapping regions. Reference data...
Stress triggering in thrust and subduction earthquakes and stress interaction between the southern San Andreas and nearby thrust and strike-slip faults
J. Lin, R.S. Stein
2004, Journal of Geophysical Research B: Solid Earth (109)
We argue that key features of thrust earthquake triggering, inhibition, and clustering can be explained by Coulomb stress changes, which we illustrate by a suite of representative models and by detailed examples. Whereas slip on surface-cutting thrust faults drops the stress in most of the adjacent crust, slip on blind...
Phylogenetic evidence for an ancient rapid radiation of Caribbean sponge-dwelling snapping shrimps (Synalpheus)
C.L. Morrison, R. Rios, J.E. Duffy
2004, Molecular Phylogenetics and Evolution (30) 563-581
A common challenge in reconstructing phylogenies involves a high frequency of short internal branches, which makes basal relationships difficult to resolve. Often it is not clear whether this pattern results from insufficient or inappropriate data, versus from a rapid evolutionary radiation. The snapping shrimp genus Synalpheus, which contains in excess...
Potential sources of hydrogel stabilization of Florida Bay lime mud sediments and implications for organic matter preservation
J.W. Louda, J.W. Loitz, A. Melisiotis, W. H. Orem
2004, Journal of Coastal Research (20) 448-463
The fine grained carbonate mud sediments of central Florida Bay are resuspended quite easily. However, this disturbance is usually limited to the surficial ('floc') layer, as the underlying sediments appear to be stabilized by an hydrogelation involving the bulk organic matter. That gelation has occurred within these sediments is suggested...
Determinism in fish assemblages of floodplain lakes of the vastly disturbed Mississippi Alluvial Valley
L.E. Miranda, G.M. Lucas
2004, Transactions of the American Fisheries Society (133) 358-370
The Mississippi Alluvial Valley between southern Illinois and southern Louisiana contains hundreds of floodplain lakes, most of which have been adversely affected by landscape modifications used to control flooding and support agriculture. We examined fish assemblages in lakes of this region to determine whether deterministic patterns developed in relation to...
Numerical analysis of seawater circulation in carbonate platforms: II. The dynamic interaction between geothermal and brine reflux circulation
G. D. Jones, F. F. Whitaker, P. L. Smart, W. E. Sanford
2004, American Journal of Science (304) 250-284
Density-driven seawater circulation may occur in carbonate platforms due to geothermal heating and / or reflux of water of elevated salinity. In geothermal circulation lateral contrasts in temperature between seawater and platform groundwaters warmed by the geothermal heat flux result in upward convective flow, with colder seawater drawn into the...
Sources of osmium to the modern oceans: New evidence from the 190Pt-186Os system
D.K. McDaniel, R.J. Walker, S. R. Hemming, M.F. Horan, H. Becker, R. I. Grauch
2004, Geochimica et Cosmochimica Acta (68) 1243-1252
High precision Os isotope analysis of young marine manganese nodules indicate that whereas the composition of modern seawater is radiogenic with respect to 187Os/188Os, it has 186Os/188Os that is within uncertainty of the chondritic value. Marine Mn nodule compositions thus indicate that the average continental source of Os to modern...
The National Map: Benefits at what cost?
D.L. Halsing, K. M. Theissen, R. L. Bernknopf
2004, GeoSpatial Solutions (14) 25-31
The U.S. Geological Survey has conducted a cost-benefit analysis of The National Map, and determined that, during its 30-year projected lifespan, the project will likely bring a net present value of benefits to society of $2.05 billion. Such a survey enhances the United States' ability to access, integrate, and apply...
Identifying areas of basin-floor recharge in the Trans-Pecos region and the link to vegetation
Michelle Ann Walvoord, Fred M. Phillips
2004, Journal of Hydrology (292) 59-74
Comparative water potential and chloride profiles (∼10 m deep) collected from four vegetation communities in the Trans-Pecos region of the Chihuahuan Desert were assessed to evaluate the potential for using vegetation patterns as a means of efficiently improving large-scale estimates of basin-floor recharge in semiarid...
Wave run-up on a high-energy dissipative beach
P. Ruggiero, R.A. Holman, R.A. Beach
2004, Journal of Geophysical Research C: Oceans (109)
Because of highly dissipative conditions and strong alongshore gradients in foreshore beach morphology, wave run-up data collected along the central Oregon coast during February 1996 stand in contrast to run-up data currently available in the literature. During a single data run lasting approximately 90 min, the significant vertical run-up elevation...
Late Quaternary glaciation of the Upper Soca River Region (Southern Julian Alps, NW Slovenia)
Milos Bavec, Slawek M. Tulaczyk, Shannon Mahan, Gregory M. Stock
2004, Sedimentary Geology (165) 265-283
Extent of Late Quaternary glaciers in the Upper Soc??a River Region (Southern Julian Alps, SE Europe) has been analyzed using a combination of geological mapping, glaciological modeling, and sediment dating (radiocarbon, U/Th series and Infrared Stimulated Luminescence-IRSL). Field investigations focused mainly on relatively well preserved Quaternary sequences in the Bovec...
An evaluation of multipass electrofishing for estimating the abundance of stream-dwelling salmonids
J.T. Peterson, R.F. Thurow, J.W. Guzevich
2004, Transactions of the American Fisheries Society (133) 462-475
Failure to estimate capture efficiency, defined as the probability of capturing individual fish, can introduce a systematic error or bias into estimates of fish abundance. We evaluated the efficacy of multipass electrofishing removal methods for estimating fish abundance by comparing estimates of capture efficiency from multipass removal estimates to capture...
First record of laughing gull (Larus atricilla) in French Polynesia
Eric A. Vanderwerf, Ray J. Pierce, T. Lee Tibbitts, J.-M. Salducci, V.A. Gill, Graham Wragg
2004, Notornis (51) 51-52
On 6 March 2003 at 0800 h and again at 1300 h, while preparing for biological surveys in the Tuamotu and Gambier archipelagos of French Polynesia, we observed an immature gull flying in Rikitea harbor on Mangareva in the Gambier Islands. On both occasions we observed the gull for several...
The perception of volcanic risk in Kona communities from Mauna Loa and Hualālai volcanoes, Hawai'i
Chris E. Gregg, Bruce F. Houghton, David M. Johnston, Douglas Paton, D. A. Swanson
2004, Journal of Volcanology and Geothermal Research (130) 179-196
Volcanic hazards in Kona (i.e. the western side of the island of Hawai'i) stem primarily from Mauna Loa and Hualālai volcanoes. The former has erupted 39 times since 1832. Lava flows were emplaced in Kona during seven of these eruptions and last impacted Kona in 1950. Hualālai last erupted in...
Importance of the Vadose Zone in analyses of unconfined aquifer tests
A.F. Moench
2004, Ground Water (42) 223-233
Analytical models commonly used to interpret unconfined aquifer tests have been based on upper-boundary (water table) conditions that do not adequately address effects of time-varying drainage from the vadose zone. As a result, measured and simulated drawdown data may not agree and hydraulic parameters may be inaccurately estimated. A 72-hour...
Upper Cretaceous sequences and sea-level history, New Jersey Coastal Plain
K.G. Miller, P. J. Sugarman, J.V. Browning, M.A. Kominz, R.K. Olsson, M.D. Feigenson, J.C. Hernandez
2004, Geological Society of America Bulletin (116) 368-393
We developed a Late Cretaceous sealevel estimate from Upper Cretaceous sequences at Bass River and Ancora, New Jersey (ODP [Ocean Drilling Program] Leg 174AX). We dated 11-14 sequences by integrating Sr isotope and biostratigraphy (age resolution ??0.5 m.y.) and then estimated paleoenvironmental changes within the sequences from lithofacies and biofacies...
Geochemical models of metasomatism in ultramafic systems: Serpentinization, rodingitization, and sea floor carbonate chimney precipitation
J.L. Palandri, M.H. Reed
2004, Geochimica et Cosmochimica Acta (68) 1115-1133
In a series of water-rock reaction simulations, we assess the processes of serpentinization of harzburgite and related calcium metasomatism resulting in rodingite-type alteration, and seafloor carbonate chimney precipitation. At temperatures from 25 to 300??C (P = 10 to 100 bar), using either fresh water or seawater, serpentinization simulations produce an...
Development of a passive, in situ, integrative sampler for hydrophilic organic contaminants in aquatic environments
D.A. Alvarez, J. D. Petty, J.N. Huckins, T. L. Jones-Lepp, D.T. Getting, J.P. Goddard, S.E. Manahan
2004, Environmental Toxicology and Chemistry (23) 1640-1648
Increasingly it is being realized that a holistic hazard assessment of complex environmental contaminant mixtures requires data on the concentrations of hydrophilic organic contaminants including new generation pesticides, pharmaceuticals, personal care products, and many chemicals associated with household, industrial, and agricultural wastes. To address this issue, we developed a passive...
Coral reef complexes at an atypical windward platform margin: Late Quaternary, southeast Florida
B. H. Lidz
2004, Geological Society of America Bulletin (116) 974-988
Major coral reef complexes rim many modern and ancient carbonate platforms. Their role in margin evolution is not fully understood, particularly when they border a margin atypical of the classic model. Classic windward margins are steeply inclined. The windward margin of southeast Florida is distinct with a very low-gradient slope...
Drag coefficients for modeling flow through emergent vegetation in the Florida Everglades
J. K. Lee, L.C. Roig, H. L. Jenter, H. M. Visser
2004, Ecological Engineering (22) 237-248
Hydraulic data collected in a flume fitted with pans of sawgrass were analyzed to determine the vertically averaged drag coefficient as a function of vegetation characteristics. The drag coefficient is required for modeling flow through emergent vegetation at low Reynolds numbers in the Florida Everglades. Parameters of the vegetation, such...
Analysis of modern and Pleistocene hydrologic exchange between Saginaw Bay (Lake Huron) and the Saginaw Lowlands area
J. R. Hoaglund III, J.J. Kolak, D.T. Long, G.J. Larson
2004, Geological Society of America Bulletin (116) 3-15
Two numerical models, one simulating present groundwater flow conditions and one simulating ice-induced hydraulic loading from the Port Huron ice advance, were used to characterize both modern and Pleistocene groundwater exchange between the Michigan Basin and near-surface water systems of Saginaw Bay (Lake Huron) and the surrounding Saginaw Lowlands area....
