Effects of marine reserves and urchin disease on southern Californian rocky reef communities
Michael D. Behrens, Kevin D. Lafferty
2004, Marine Ecology Progress Series (279) 129-139
While the species level effects of marine reserves are widely recognized, community level shifts due to marine reserves have only recently been documented. Protection from fishing of top predators may lead to trophic cascades, which have community-wide implications. Disease may act in a similar manner, regulating population levels of dominant...
Source parameters and rupture velocities of microearthquakes in western Nagano, Japan, determined using stopping phases
K. Imanishi, M. Takeo, W.L. Ellsworth, H. Ito, T. Matsuzawa, Y. Kuwahara, Y. Iio, S. Horiuchi, S. Ohmi
2004, Bulletin of the Seismological Society of America (94) 1762-1780
We use an inversion method based on stopping phases (Imanishi and Takeo, 2002) to estimate the source dimension, ellipticity, and rupture velocity of microearthquakes and investigate the scaling relationships between source parameters. We studied 25 earthquakes, ranging in size from M 1.3 to M 2.7, that occurred between May and...
When should Mayfield model data be discarded?
T.R. Stanley
2004, The Wilson Bulletin (116) 267-269
Much confusion exists over the proper way to handle nest-fate data collected after the fledge date when using the Mayfield method. I provide a simple numerical example showing how use of these data can bias estimates of daily survival probability, and present a likelihood function demonstrating that nest-fate data collected...
Multimodal approach to seismic pavement testing
N. Ryden, C.B. Park, P. Ulriksen, R. D. Miller
2004, Journal of Geotechnical and Geoenvironmental Engineering (130) 636-645
A multimodal approach to nondestructive seismic pavement testing is described. The presented approach is based on multichannel analysis of all types of seismic waves propagating along the surface of the pavement. The multichannel data acquisition method is replaced by multichannel simulation with one receiver. This method uses only one accelerometer-receiver...
Effect of temporal resolution on the accuracy of ADCP measurements
J. A. Gonzalez-Castro, K. Oberg, James J. Duncker
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
The application of acoustic Doppler current profilers (ADCP's) in river flow measurements is promoting a great deal of progress in hydrometry. ADCP's not only require shorter times to collect data than traditional current meters, but also allow streamflow measurements at sites where the use of conventional meters is either very...
Degradates provide insight to spatial and temporal trends of herbicides in ground water
D.W. Kolpin, D.J. Schnoebelen, E.M. Thurman
2004, Groundwater (42) 601-608
Since 1995, a network of municipal wells in Iowa, representing all major aquifer types (alluvial, bedrock/karst region, glacial drift, bedrock/nonkarst region), has been repeatedly sampled for a broad suite of herbicide compounds yielding one of the most comprehensive statewide databases of such compounds currently available in the United States. This...
Consumption dynamics of the adult piscivorous fish community in Spirit Lake, Iowa
H. Liao, C.L. Pierce, J. G. Larscheid
2004, North American Journal of Fisheries Management (24) 890-902
At Spirit Lake, one of Iowa's most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to...
Geochemical characterization of tarballs on beaches along the California coast. Part I - Shallow seepage impacting the Santa Barbara Channel Islands, Santa Cruz, Santa Rosa and San Miguel
F. D. Hostettler, R.J. Rosenbauer, T.D. Lorenson, J. Dougherty
2004, Organic Geochemistry (35) 725-746
Tarballs are common along the southern California coastline. This study investigates tarballs from beaches along this coastline, with a focus on Santa Cruz, Santa Rosa, and San Miquel Islands in the Santa Barbara Channel. The tarballs were fingerprinted using biomarker and stable carbon isotope parameters, and then grouped according to...
Duration of the Arctic sea ice melt season: Regional and interannual variability, 1979-2001
G. I. Belchansky, David C. Douglas, Nikita G. Platonov
2004, Journal of Climate (17) 67-80
Melt onset dates, freeze onset dates, and melt season duration were estimated over Arctic sea ice, 1979–2001, using passive microwave satellite imagery and surface air temperature data. Sea ice melt duration for the entire Northern Hemisphere varied from a 104-day minimum in 1983 and 1996 to a 124-day maximum in...
A GIS analysis of suitability for construction aggregate recycling sites using regional transportation network and population density features
G.R. Robinson Jr., K. E. Kapo
2004, Resources, Conservation and Recycling (42) 351-365
Aggregate is used in road and building construction to provide bulk, strength, support, and wear resistance. Reclaimed asphalt pavement (RAP) and reclaimed Portland cement concrete (RPCC) are abundant and available sources of recycled aggregate. In this paper, current aggregate production operations in Virginia, Maryland, and the District of Columbia are...
Inferring time‐varying recharge from inverse analysis of long‐term water levels
Jesse E. Dickinson, R. T. Hanson, T.P.A. Ferre, S. A. Leake
2004, Water Resources Research (40)
Water levels in aquifers typically vary in response to time‐varying rates of recharge, suggesting the possibility of inferring time‐varying recharge rates on the basis of long‐term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to...
Detecting denning polar bears with Forward-Looking Infrared (FLIR) imagery
Steven C. Amstrup, G. York, T. L. McDonald, R. Nielson, Kristin S. Simac
2004, BioScience (54) 337-344
Polar bears give birth in snow dens in midwinter and remain in dens until early spring. The survival and development of cubs is dependent on a stable environment within the maternal den. To mitigate potential disruption of polar bear denning by existing and proposed petroleum activities, we used forward-looking infrared...
Time-series photographs of the sea floor in western Massachusetts Bay: June 1997 to June 1998
Bradford Butman, P. Soupy Alexander, Michael H. Bothner
2004, Data Series 87
This report presents time-series photographs of the sea floor obtained from an instrumented tripod deployed at Site A in western Massachusetts Bay (42° 22.6' N., 70? 47.0' W., 30 m water depth, from June 1997 through June 1998. Site A is approximately 1 km south of an ocean outfall that...
Species boundaries, phylogeography, and conservation genetics of the red-legged frog (Rana aurora/draytonii) complex
H. Bradley Shaffer, Gary M. Fellers, S. Randal Voss, J. C. Oliver, Gregory B. Pauly
2004, Molecular Ecology (13) 2667-2677
The red-legged frog, Rana aurora, has been recognized as both a single, polytypic species and as two distinct species since its original description 150 years ago. It is currently recognized as one species with two geographically contiguous subspecies, aurora and draytonii; the latter is protected under the US Endangered Species Act....
A quantitative approach to identifying predators from nest remains
R. Michael Anthony, J.B. Grand, T.F. Fondell, B.F. Manly
2004, Journal of Field Ornithology (75) 40-48
Nesting success of Dusky Canada Geese (Branta canadensis occidentalis) has declined greatly since a major earthquake affected southern Alaska in 1964. To identify nest predators, we collected predation data at goose nests and photographs of predators at natural nests containing artificial eggs in 1997-2000. To document feeding behavior by nest...
Mapping of the Culann-Tohil region of Io from Galileo imaging data
D.A. Williams, Paul M. Schenk, Jeffrey M. Moore, Laszlo P. Keszthelyi, Elizabeth P. Turtle, Windy L. Jaeger, Jani Radebaugh, Moses P. Milazzo, Rosaly Lopes, Ronald Greeley
2004, Icarus (169) 80-97
We have used Galileo spacecraft data to produce a geomorphologic map of the Culann–Tohil region of Io's antijovian hemisphere. This region includes a newly discovered shield volcano, Tsũi Goab Tholus and a neighboring bright flow field, Tsũi Goab Fluctus, the active Culann Patera and the enigmatic Tohil Mons-Radegast Patera–Tohil Patera complex. Analysis...
Estimating the use of morphometric measurements from museum specimens for sex determination in Mountain Plovers (Charadrius montanus)
W.M. Iko, S.J. Dinsmore, F.L. Knopf
2004, Western North American Naturalist (64) 492-496
The Mountain Plover (Charadrius montanus) is a shorebird species endemic to the dry, terrestrial ecosystems of the Great Plains and southwestern United States. Breeding Bird Survey data suggest that Mountain Plover populations have declined by >60% in the last 30 years. A better understanding of the population dynamics of the...
Tire-wear particles as a source of zinc to the environment
T.B. Councell, K.U. Duckenfield, E. R. Landa, E. Callender
2004, Environmental Science & Technology (38) 4206-4214
Tire-tread material has a zinc (Zn) content of about 1 wt %. The quantity of tread material lost to road surfaces by abrasion has not been well characterized. Two approaches were used to assess the magnitude of this nonpoint source of Zn in the U.S. for the...
Great earthquakes and tsunamis of the past 2000 years at the Salmon River estuary, central Oregon coast, USA
A.R. Nelson, A.C. Asquith, W.C. Grant
2004, Bulletin of the Seismological Society of America (94) 1276-1292
Four buried tidal marsh soils at a protected inlet near the mouth of the Salmon River yield definitive to equivocal evidence for coseismic subsidence and burial by tsunami-deposited sand during great earthquakes at the Cascadia subduction zone. An extensive, landward-tapering sheet of sand overlies a peaty tidal-marsh soil over much...
Remote sensing of vegetation and land-cover change in Arctic Tundra Ecosystems
Douglas A. Stow, Allen Hope, David McGuire, David Verbyla, John A. Gamon, Fred Huemmrich, Stan Houston, Charles H. Racine, Matthew Sturm, Ken D. Tape, Larry D. Hinzman, Kenji Yoshikawa, Craig E. Tweedie, Brian Noyle, Cherie Silapaswan, David C. Douglas, Brad Griffith, Gensuo Jia, Howard E. Epstein, Donald A. Walker, Scott Daeschner, Aaron Petersen, Liming Zhou, Ranga B. Myneni
2004, Remote Sensing of Environment (89) 281-308
The objective of this paper is to review research conducted over the past decade on the application of multi-temporal remote sensing for monitoring changes of Arctic tundra lands. Emphasis is placed on results from the National Science Foundation Land–Air–Ice Interactions (LAII) program and on optical remote sensing techniques. Case...
Ambient noise levels in the continental United States
D.E. McNamara, R.P. Buland
2004, Bulletin of the Seismological Society of America (94) 1517-1527
We present a new approach to characterize the background seismic noise across the continental United States. Using this approach, power spectral density (PSD) is estimated at broadband seismic stations for frequencies ranging from ∼0.01 to 16 Hz. We selected a large number of 1-hr waveform segments during a 3-yr...
Use and interpretation of logistic regression in habitat-selection studies
Kim A. Keating, Steve Cherry
2004, Journal of Wildlife Management (68) 774-789
Logistic regression is an important tool for wildlife habitat-selection studies, but the method frequently has been misapplied due to an inadequate understanding of the logistic model, its interpretation, and the influence of sampling design. To promote better use of this method, we review its application and interpretation under 3...
Crustal deformation measurements in Guerrero, Mexico
K.M. Larson, A.R. Lowry, V. Kostoglodov, W. Hutton, O. Sanchez, K. Hudnut, G. Suarez
2004, Journal of Geophysical Research B: Solid Earth (109)
GPS measurements of crustal deformation in Guerrero, southern Mexico, include surveys collected between 1992 and 2001 as well as continuous GPS measurements at a few sites. These geodetic observations are used to calculate interseismic deformation rates and assess the presence and possible location of transient deformation during the period encompassing...
Paleogeodetic records of seismic and aseismic subduction from central Sumatran microatolls, Indonesia
D.H. Natawidjaja, K. Sieh, S.N. Ward, H. Cheng, R. Lawrence Edwards, J. Galetzka, B.W. Suwargadi
2004, Journal of Geophysical Research B: Solid Earth (109)
We utilize coral microatolls in western Sumatra to document vertical deformation associated with subduction. Microatolls are very sensitive to fluctuations in sea level and thus act as natural tide gauges. They record not only the magnitude of vertical deformation associated with earthquakes (paleoseismic data), but also continuously track the long-term...
Frequency-dependent Lg Q within the continental United States
D. Erickson, D.E. McNamara, H.M. Benz
2004, Bulletin of the Seismological Society of America (94) 1630-1643
Frequency-dependent crustal attenuation (1/Q) is determined for seven distinct physiographic/tectonic regions of the continental United States using high-quality Lg waveforms recorded on broadband stations in the frequency band 0.5 to 16 Hz. Lg attenuation is determined from time-domain amplitude measurements in one-octave frequency bands centered on the frequencies 0.75, 1.0,...
