Recordings from the deepest borehole in the New Madrid Seismic Zone
Z. Wang, E.W. Woolery
2006, Seismological Research Letters (77) 148-153
The recordings at the deepest vertical strong-motion array (VSAS) from three small events, the 21 October 2004 Tiptonville, Tennessee, earthquake; the 10 February 2005 Arkansas earthquake; and the 2 June 2005 Ridgely, Tennessee, earthquake show some interesting wave-propagation phenomena through the soils: the S-wave is attenuated from 260 m to...
Teachers doing science: An authentic geology research experience for teachers
D. Hemler, T. Repine
2006, Journal of Geoscience Education (54) 93-102
Fairmont State University (FSU) and the West Virginia Geological and Economic Survey (WVGES) provided a small pilot group of West Virginia science teachers with a professional development session designed to mimic experiences obtained by geology majors during a typical summer field camp. Called GEOTECH, the program served as a research...
An assessment of the impact of the 2003 EPRI ground-motion prediction models on the USGS national seismic-hazard maps
C. Cramer
2006, Bulletin of the Seismological Society of America (96) 1159-1169
Ground-motion attenuation relations have an important impact on seismic hazard analyses. Ground-motion modeling is particularly sensitive to assumptions about wave-propagation attenuation (crustal Q and geometrical spreading), as well as source and site conditions. Studies of path attenuation from earthquakes in eastern North America (ENA) provide insights into the appropriateness of...
Widespread presence of naturally occurring perchlorate in high plains of Texas and New Mexico
S. Rajagopalan, T.A. Anderson, L. Fahlquist, Ken A. Rainwater, M. Ridley, W.A. Jackson
2006, Environmental Science & Technology (40) 3156-3162
Perchlorate (ClO4-) occurrence in groundwater has previously been linked to industrial releases and the historic use of Chilean nitrate fertilizers. However, recently a number of occurrences have been identified for which there is no obvious anthropogenic source. Groundwater from an area of 155 000 km2 in 56 counties in northwest...
Genetic and demographic criteria for defining population units for conservation: The value of clear messages
Daniel Esler, S. A. Iverson, D.J. Rizzolo
2006, Condor (108) 480-483
In a recent paper on Harlequin Duck (Histrionicus histrionicus) interannual site fidelity (Iverson et al. 2004), we concluded that wintering populations were demographically structured at a finer geographic scale than that at which genetic differentiation was observed and that conservation efforts should recognize this degree of demographic independence. In a...
Status of soil acidification in North America
M.E. Fenn, T.G. Huntington, S.B. Mclaughlin, C. Eagar, A. Gomez, R.B. Cook
2006, Journal of Forest Science (52) 3-13
Forest soil acidification and depletion of nutrient cations have been reported for several forested regions in North America, predominantly in the eastern United States, including the northeast and in the central Appalachians, but also in parts of southeastern Canada and the southern U.S. Continuing regional inputs of nitrogen and sulfur...
Temporal and spatial variability in the flow and dispersal of suspended-sediment on a fringing reef flat, Molokai, Hawaii
M.K. Presto, A.S. Ogston, C. D. Storlazzi, M.E. Field
2006, Estuarine, Coastal and Shelf Science (67) 67-81
A multi-year study was conducted on a shallow fringing reef flat on Molokai, Hawaii to determine the temporal and spatial dispersal patterns of terrigenous suspended sediment. During this study, trade-wind conditions existed for the majority of the year on the reef flat. The trade-wind conditions produced strong currents and resuspended...
Character and distribution of exposed glaciodeltaic deposits off outer Cape Cod, Massachusetts, and their effects on hydrogeology and benthic habitats
L.J. Poppe, D.S. Foster, W. W. Danforth
2006, Geo-Marine Letters (26) 51-57
Seabed outcrops of glaciodeltaic sediments were identified in four places east of Cape Cod, Massachusetts, during seismic-reflection, multibeam bathymetric and backscatter, bottom photographic, and sediment sampling surveys. These strata record coarser-grained ice-proximal glaciofluvial topset to finer-grained distal glaciolacustrine bottomset deposition within deltaic systems that prograded southwestward into glacial lakes from...
Unusual Holocene and late Pleistocene carbonate sedimentation in Bear Lake, Utah and Idaho, USA
W. Dean, J. Rosenbaum, G. Skipp, S. Colman, R. Forester, A. Liu, K. Simmons, J. Bischoff
2006, Sedimentary Geology (185) 93-112
Bear Lake (Utah-Idaho, USA) has been producing large quantities of carbonate minerals of varying mineralogy for the past 17,000 years. The history of sedimentation in Bear Lake is documented through the study of isotopic ratios of oxygen, carbon, and strontium, percent organic carbon, percent CaCO3, X-ray diffraction mineralogy, HCl-leach inorganic...
KGS-HighK: A Fortran 90 program for simulation of hydraulic tests in highly permeable aquifers
X. Zhan, J.J. Butler Jr.
2006, Computers & Geosciences (32) 704-707
Slug and pumping tests (hydraulic tests) are frequently used by hydrogeologists to obtain in-situ estimates of the transmissive and storage properties of a formation (Streltsova, 1988; Kruseman and de Ridder, 1990; Butler, 1998). In aquifers of high hydraulic conductivity, hydraulic tests are affected by mechanisms that are not considered in...
A molecular dawn for biogeochemistry
D.R. Zak, C.B. Blackwood, M. P. Waldrop
2006, Trends in Ecology and Evolution (21) 288-295
Biogeochemistry is at the dawn of an era in which molecular advances enable the discovery of novel microorganisms having unforeseen metabolic capabilities, revealing new insight into the underlying processes regulating elemental cycles at local to global scales. Traditionally, biogeochemical inquiry began by studying a process of interest, and then focusing...
Distribution and abundance of forest birds in low-altitude habitat on Hawai'i Island: Evidence for range expansion of native species
C.S. Spiegel, P.J. Hart, B.L. Woodwort, E.J. Tweed, J.J. Leburn
2006, Bird Conservation International (16) 175-185
The Hawaiian honeycreepers are thought to be limited primarily to middle- and high-altitude wet forests due to anthropogenic factors at lower altitudes, especially introduced mosquitotransmitted avian malaria. However, recent research has demonstrated that at least one native species, the Hawai'i 'Amakihi (Hemignathus virens virens), is common in areas of active...
The sand seas of titan: Cassini RADAR observations of longitudinal dunes
R. D. Lorenz, S. Wall, J. Radebaugh, G. Boubin, E. Reffet, M. Janssen, E. Stofan, R. Lopes, Randolph L. Kirk, C. Elachi, J. Lunine, Ken Mitchell, F. Paganelli, Laurence A. Soderblom, C. Wood, L. Wye, H. Zebker, Y. Anderson, S. Ostro, M. Allison, R. Boehmer, P. Callahan, P. Encrenaz, G.G. Ori, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, W. Johnson, K. Kelleher, D. Muhleman, G. Picardi, F. Posa, L. Roth, R. Seu, S. Shaffer, B. Stiles, S. Vetrella, E. Flamini, R. West
2006, Science (312) 724-727
The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show ∼100-meter ridges consistent...
Gas slug ascent through changes in conduit diameter: Laboratory insights into a volcano-seismic source process in low-viscosity magmas
M.R. James, S.J. Lane, B. A. Chouet
2006, Journal of Geophysical Research B: Solid Earth (111)
Seismic signals generated during the flow and degassing of low-viscosity magmas include long-period (LP) and very-long-period (VLP) events, whose sources are often attributed to dynamic fluid processes within the conduit. We present the results of laboratory experiments designed to investigate whether the passage of a gas slug through regions of...
Expert forecasts and the emergence of water scarcity on public agendas
E.A. Graffy
2006, Society and Natural Resources (19) 465-472
Expert forecasts of worldwide water scarcity depict conditions that call for proactive, preventive, coordinated water governance, but they have not been matched by public agendas of commensurate scope and urgency in the United States. This disconnect can not be adequately explained without some attention to attributes of forecasts themselves. I...
Morphometric discrimination of early life stage Lampetra tridentata and L richardsoni (Petromyzonidae) from the Columbia river basin
M.H. Meeuwig, J.M. Bayer, R.A. Reiche
2006, Journal of Morphology (267) 623-633
The effectiveness of morphometric and meristic characteristics for taxonomic discrimination of Lampetra tridentata and L. richardsoni (Petromyzonidae) during embryological, prolarval, and early larval stages (i.e., age class 1) were examined. Mean chorion diameter increased with time from fertilization to hatch and was significantly greater for L. tridentata than for L....
Parent birds assess nest predation risk and adjust their reproductive strategies
J.J. Fontaine, T. E. Martin
2006, Ecology Letters (9) 428-434
Avian life history theory has long assumed that nest predation plays a minor role in shaping reproductive strategies. Yet, this assumption remains conspicuously untested by broad experiments that alter environmental risk of nest predation, despite the fact that nest predation is a major source of reproductive failure. Here, we examined...
Development of allometric relations for three mangrove species in South Florida for use in the Greater Everglades Ecosystem restoration
T. J. Smith III, K.R.T. Whelan
2006, Wetlands Ecology and Management (14) 409-419
Mathematical relations that use easily measured variables to predict difficult-to-measure variables are important to resource managers. In this paper we develop allometric relations to predict total aboveground biomass and individual components of biomass (e.g., leaves, stems, branches) for three species of mangroves for Everglades National Park, Florida, USA. The Greater...
Tsunami-generated boulder ridges in Lake Tahoe, California-Nevada
J.G. Moore, R.A. Schweickert, J.E. Robinson, M.M. Lahren, Christopher A. Kitts
2006, Geology (34) 965-968
An array of east-trending ridges 1-2 m high and up to 2 km long occurs on the Tahoe City shelf, a submerged wave-cut bench <15 m deep in the northwest sector of the lake. The shelf is just north of the amphitheater of the giant subaqueous 10 km3 McKinney Bay...
Seed dispersal in fens
B. Middleton, R. Van Diggelen, K. Jensen
2006, Conference Paper, Applied Vegetation Science
Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower...
Effects of abdominally implanted radiotransmitters with percutaneous antennas on migration, reproduction, and survival of Canada geese
Jerry W. Hupp, John M. Pearce, Daniel M. Mulcahy, David A. Miller
2006, Journal of Wildlife Management (70) 812-822
Abdominally implanted radiotransmitters with percutaneous antennas are increasingly used to monitor movements, survival, and reproduction of waterbirds. However, there has been relatively little assessment of the effects of such radios on avian demographic parameters or migration. We implanted either a 26- or 35-g abdominal transmitter with percutaneous antenna in 198...
Quantitative estimation of minimum offset for multichannel surface-wave survey with actively exciting source
Y. Xu, J. Xia, R. D. Miller
2006, Journal of Applied Geophysics (59) 117-125
Multichannel analysis of surface waves is a developing method widely used in shallow subsurface investigations. The field procedures and related parameters are very important for successful applications. Among these parameters, the source-receiver offset range is seldom discussed in theory and normally determined by empirical or semi-quantitative methods in current practice....
Spring census of mid-continent sandhill cranes using aerial infrared videography
P.J. Kinzel, J. M. Nelson, R. S. Parker, L.R. Davis
2006, Journal of Wildlife Management (70) 70-77
Aerial infrared videography was used to map spatial distributions of nocturnal sandhill crane (Grus canadensis) flocks and determine crane densities within roosts as an alternative to the currently used diurnal photo-corrected ocular transect method to estimate the size of the mid-continental population. The densities determined from samples taken over the...
Seasonal effects of the zebra mussel (Dreissena polymorpha) on sediment denitrification rates in Pool 8 of the Upper Mississippi River
Denise A. Bruesewitz, Jennifer L. Tank, Melody J. Bernot, William B. Richardson, Eric A. Strauss
2006, Canadian Journal of Fisheries and Aquatic Sciences (63) 957-969
Zebra mussels (Dreissena polymorpha) have altered the structure of invaded ecosystems and exhibit characteristics that suggest they may influence ecosystem processes such as nitrogen (N) cycling. We measured denitrification rates seasonally on sediments underlying zebra mussel beds collected from the impounded zone of Navigation Pool 8 of the Upper Mississippi...
Sorption processes affecting arsenic solubility in oxidized surface sediments from Tulare Lake Bed, California
S. Gao, S. Goldberg, M.J. Herbel, A.T. Chalmers, R. Fujii, K.K. Tanji
2006, Chemical Geology (228) 33-43
Elevated concentrations of arsenic (As) in shallow groundwater in Tulare Basin pose an environmental risk because of the carcinogenic properties of As and the potential for its migration to deep aquifers that could serve as a future drinking water source. Adsorption and desorption are hypothesized to be the major processes...
