Search Results

This study investigates the behavior of migrant eels as they approached the Patea hydroelectric dam on the West Coast of the North Island, New Zealand. Seventeen mature migrant eels (870-1,240 mm; 2,000-6,380 g) were implanted with coded acoustic transmitters and released. Their movements in the reservoir were monitored for 14...

Landslides in the hilly terrain along the Kansas and Missouri rivers in northeastern Kansas have caused millions of dollars in property damage during the last decade. To address this problem, a statistical method called multiple logistic regression has been used to create a landslide-hazard map for Atchison, Kansas, and surrounding...

Radiotelemetry was used to document population structure in adult rainbow trout Oncorhynchus mykiss from the Alagnak River, southwest Alaska. Rainbow trout (N = 134) longer than 440 mm were implanted with radio transmitters and tracked for varying periods from July 1997 to April 1999. Fifty-eight radio-tagged fish were tracked for...

Fish community data collected from 24 major river basins between 1993 and 1998 as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess multiple-reach (three consecutive reaches) and multiple-year (three consecutive years) variability in samples collected at a site. Variability was assessed using the coefficient...

Percina (Cottogaster) aurora is an imperiled species under consideration for listing by the U.S. Fish and Wildlife Service. To better understand habitat use of P. aurora, we studied a related and more abundant Cottogasterspecies, Percina copelandi, from the Ouachita River, Arkansas. We used a laboratory stream system to examine mesohabitat selection (pools versus riffles)...

Shifts in the demographic and economic character of the Greater Yellowstone Ecosystem (GYE) are driving patterns of land cover and land use change in the region. Such changes may have important consequences for ecosystem functioning. The objective of this paper is to quantify the trajectories and rates of change in...

We consider expected relationships between apparent stress τa and static stress drop Δτs using a standard energy balance and find τa = Δτs (0.5 - ξ), where ξ is stress overshoot. A simple implementation of this balance is to assume overshoot is constant; then apparent stress should vary linearly with stress drop, consistent with spectral theories (Brune, 1970) and dynamic crack models (Madariaga, 1976). Normalizing this...

Engineering seismoscope data collected at distances less than 300 km for the M 7.7 Bhuj, India, mainshock are compatible with ground-motion attenuation in eastern North America (ENA). The mainshock ground-motion data have been corrected to a common geological site condition using the factors of Joyner and Boore (2000) and a...

Data on three major determinants of the carbon storage in terrestrial ecosystems are used with the process-based Terrestrial Ecosystem Model (TEM) to simulate the combined effect of climate variability, increasing atmospheric CO2 concentration, and cropland establishment and abandonment on the exchange of CO2 between the atmosphere and monsoon Asian ecosystems....

Forty-two bench samples of the Sewickley coal bed were collected from seven localities in the northern Appalachian Basin and analyzed palynologically, petrographically, and geochemically. The Sewickley coal bed occurs in the middle of the Pittsburgh Formation (Monongahela Group) and is of Late Pennsylvanian age. Palynologically, it is dominated by spores...

Thermistor chains and acoustic Doppler current profilers were deployed at the northern and southern ends of Monterey Bay to examine the thermal and hydrodynamic structure of the inner (h ??? 20 m) shelf of central California. These instruments sampled temperature and current velocity at 2-min intervals over a 13-month period...

Habitat loss is a major reason for the decline of grassland birds in North America. Five habitats (pastures, hayfields, rowcrop fields, small-grain fields, Conservation Reserve Program fields) compose most of the habitat used by grassland birds in the Midwest United States. Growing and harvesting switchgrass (Panicum virgatum) as a biomass...

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a 14-band multispectral instrument on board the Earth Observing System (EOS), TERRA. The three bands between 0.52 and 0.86 ??m and the six bands from 1.60 and 2.43 ??m, which have 15- and 30-m spatial resolution, respectively, were selected primarily...

Many countries periodically produce national reports on the status and changes of forest resources, using statistical surveys and spatial mapping of remotely sensed data. At the global level, the Food and Agriculture Organization (FAO) of the United Nations has conducted a Forest Resources Assessment (FRA) program every 10 yr since...

The ability to measure environmental levels of 36Cl by Accelerator Mass Spectrometry and 3H by 3He-ingrowth Mass Spectrometry has made it possible to use the pulses of these two isotopes released into the atmosphere during nuclear weapons testing as tracers of Cl and water movement in soils and groundwater. The...

Multi-channel seismic data acquired on the South Shetland margin, northern Antarctic Peninsula, show that Bottom Simulating Reflectors (BSRs) are widespread in the area, implying large volumes of gas hydrates. In order to estimate the volume of gas hydrate in the area, interval velocities were determined using a 1-D velocity inversion...

As part of a COSI Academy research project, data from a recent statewide analysis of effective groundwater recharge were reexamined by students to further discern relations between recharge and selected environmental characteristics of individual drainage basins: 1) location of the main stem of a river relative to coarse and fine...

Advanced Land Imager (ALI), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and Hyperion imaging spectrometer data covering an area in the Central Andes between Volcan Socompa and Salar de Llullaillaco were used to map hydrothermally altered rocks associated with several young volcanic systems. Six ALI channels in the visible...

This paper presents the first systematic comparison, using historical and paleoflood data, of moments-based flood frequency methods. Peak flow estimates were compiled from streamflow-gaging stations with historical and/or paleoflood data at 36 sites located in the United States, Argentina, United Kingdom and China, covering a diverse range of hydrologic conditions....

The annual timing of river flows is a good indicator of climate-related changes, or lack of changes, for rivers with long-term data that drain unregulated basins with stable land use. Changes in the timing of annual winter/spring (January 1 to May 31) and fall (October 1 to December 31) center...

We present results from an analysis of anisotropy in marine sediments using walkaway vertical seismic profiles from the Blake Ridge, offshore South Carolina. We encountered transverse isotropy (TI) with a vertical symmetry axis in a gas-hydrate-bearing unit of clay and claystone with Thomsen parameters ?? = 0.05 ?? 0.02 and...

Determining natural background concentrations of nutrients in watersheds in the developed world has been hampered by a lack of pristine sampling sites covering a range of climatic conditions and basin sizes. Using data from 63 minimally impacted U.S. Geological Survey reference basins, we developed empirical models of the background yield...

Recent studies have demonstrated a plausible link between surface and near-surface tectonic features and the vertical projection of the Commerce geophysical lineament (CGL). The CGL is a 5- to 10-km-wide zone of basement magnetic and gravity anomalies traceable for more than 600 km, extending from Arkansas through southeast Missouri and...

Power analysis is helpful in defining goals for ecological monitoring and evaluating the performance of ongoing efforts. I examined detection standards proposed for population monitoring of seabirds using two programs (MONITOR and TRENDS) specially designed for power analysis of trend data. Neither program models within- and among-years components of variance...

Hydraulic, sediment, land-use, and rock-erosivity data of 22 alluvial streams were used to evaluate conditions of bedload transport and the performance of selected bedload-transport equations. Transport categories of transport-limited (TL), partially transport-limited (PTL), and supply-limited (SL) were identified by a semiquantitative approach that considers hydraulic constraints on sediment movement and...