Exploring mechanisms underlying sex-specific differences in mortality of Lake Michigan bloaters
D.B. Bunnell, C.P. Madenjian, M.W. Rogers, J.D. Holuszko, L.J. Begnoche
2012, Transactions of the American Fisheries Society (141) 204-214
Sex-specific differences in mortality rates have been observed among freshwater and marine fish taxa, and underlying mechanisms can include sex-specific differences in (1) age at maturity, (2) growth rate, or (3) activity or behavior during the spawning period. We used a long-term (1973–2009) Lake Michigan data set to evaluate whether...
Verifiable metamodels for nitrate losses to drains and groundwater in the Corn Belt, USA
Bernard T. Nolan, Robert W. Malone, Jo Ann M. Gronberg, K.R. Thorp, Liwang Ma
2012, Environmental Science & Technology (46) 901-908
Nitrate leaching in the unsaturated zone poses a risk to groundwater, whereas nitrate in tile drainage is conveyed directly to streams. We developed metamodels (MMs) consisting of artificial neural networks to simplify and upscale mechanistic fate and transport models for prediction of nitrate losses by drains and leaching in the...
Impact of wildfire and slope aspect on soil temperature in a mountainous environment
Brian A. Ebel
2012, Vadose Zone Journal (11)
Soil temperature changes after landscape disturbance impact hydrology, ecology, and geomorphology. This study used field measurements to examine wildfire and aspect effects on soil temperatures. Combustion of the litter and duff layers on north-facing slopes removed pre-fire aspect-driven soil temperature controls.Wildfire is one of the most significant disturbances in mountainous...
The origins of Late Quaternary debris avalanche and debris flow deposits from Cofre de Perote volcano, México
Rodolfo Diaz-Castellon, Bernard E. Hubbard, Gerardo Carrasco-Nunez, Jose Luis Rodriguez-Vargas
2012, Geosphere (8) 950-971
Cofre de Perote volcano is a compound, shield-like volcano located in the northeastern Trans-Mexican volcanic belt. Large debris avalanche and lahar deposits are associated with the evolution of Cofre. The two best preserved of these debris-avalanche and debris-flow deposits are the ∼42 ka “Los Pescados debris flow” deposit and...
Updated determination of stress parameters for nine well-recorded earthquakes in eastern North America
David M. Boore
2012, Seismological Research Letters (83) 190-199
Stress parameters (Δσ) are determined for nine relatively well-recorded earthquakes in eastern North America for ten attenuation models. This is an update of a previous study by Boore et al. (2010). New to this paper are observations from the 2010 Val des Bois earthquake, additional observations for the 1988 Saguenay and 2005...
Burn severity mapping in Australia 2009
Randy McKinley, J. Clark, Jennifer Lecker
2012, Conference Paper, International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8
In 2009, the Victoria Department of Sustainability and Environment estimated approximately 430,000 hectares of Victoria Australia were burned by numerous bushfires. Burned Area Emergency Response (BAER) teams from the United States were deployed to Victoria to assist local fire managers. The U.S. Geological Survey Earth Resources Observation and Science Center...
Mercury speciation and transport via submarine groundwater discharge at a southern California coastal lagoon system
P.M. Ganguli, Christopher H. Conaway, Peter W. Swarzenski, J. A. Izbicki, A.R. Flegal
2012, Environmental Science & Technology (46) 1480-1488
We measured total mercury (HgT) and monomethylmercury (MMHg) concentrations in coastal groundwater and seawater over a range of tidal conditions near Malibu Lagoon, California, and used 222Rn-derived estimates of submarine groundwater discharge (SGD) to assess the flux of mercury species to nearshore seawater. We infer a groundwater-seawater mixing scenario based...
Histologic, immunologic and endocrine biomarkers indicate contaminant effects in fishes of the Ashtabula River
L. R. Iwanowicz, V. S. Blazer, N.P. Hitt, S. D. McCormick, D.S. Devault, C. A. Ottinger
2012, Ecotoxicology (21) 165-182
The use of fish as sentinels of aquatic ecosystem health is a biologically relevant approach to environmental monitoring and assessment. We examined the health of the Ashtabula River using histologic, immunologic, and endocrine biomarkers in brown bullhead (BB; Ameiurus nebulosus) and largemouth bass (Micropterus salmoides) and compared fish collected from...
Novel plant communities limit the effects of a managed flood to restore riparian forests along a large regulated river
D.J. Cooper, D.C. Andersen
2012, River Research and Applications (28) 204-215
Dam releases used to create downstream flows that mimic historic floods in timing, peak magnitude and recession rate are touted as key tools for restoring riparian vegetation on large regulated rivers. We analysed a flood on the 5th‐order Green River below Flaming Gorge Dam, Colorado, in a broad alluvial valley...
Evaluation of MODFLOW-LGR in connection with a synthetic regional-scale model
T.N. Vilhelmsen, S. Christensen, Steffen W. Mehl
2012, Ground Water (50) 118-132
This work studies costs and benefits of utilizing local‐grid refinement (LGR) as implemented in MODFLOW‐LGR to simulate groundwater flow in a buried tunnel valley interacting with a regional aquifer. Two alternative LGR methods were used: the shared‐node (SN) method and the ghost‐node (GN) method. To conserve flows the SN method...
Has the magnitude of floods across the USA changed with global CO 2 levels?
R.M. Hirsch, K.R. Ryberg
2012, Hydrological Sciences Journal (57) 1-9
Statistical relationships between annual floods at 200 long-term (85-127 years of record) streamgauges in the coterminous United States and the global mean carbon dioxide concentration (GMCO2) record are explored. The streamgauge locations are limited to those with little or no regulation or urban development. The coterminous US is divided into...
Holocene aridification of India
C. Ponton, L. Giosan, T.I. Eglinton, D.Q. Fuller, J.E. Johnson, P. Kumar, Timothy S. Collett
2012, Geophysical Research Letters (39)
Spanning a latitudinal range typical for deserts, the Indian peninsula is fertile instead and sustains over a billion people through monsoonal rains. Despite the strong link between climate and society, our knowledge of the long‐term monsoon variability is incomplete over the Indian subcontinent. Here we reconstruct the Holocene paleoclimate in...
El Niño-Southern oscillation variability from the late cretaceous marca shale of California
Andrew Davies, Alan E.S. Kemp, Graham P. Weedon, John A. Barron
2012, Geology (40) 15-18
Changes in the possible behavior of El Niño–Southern Oscillation (ENSO) with global warming have provoked interest in records of ENSO from past “greenhouse” climate states. The latest Cretaceous laminated Marca Shale of California permits a seasonal-scale reconstruction of water column flux events and hence interannual paleoclimate variability. The annual flux...
Leveraging modern climatology to increase adaptive capacity across protected area networks
J.E. Davison, L.J. Graumlich, E.L. Rowland, Gregory T. Pederson, D.D. Breshears
2012, Global Environmental Change (22) 268-274
Human-driven changes in the global environment pose an increasingly urgent challenge for the management of ecosystems that is made all the more difficult by the uncertain future of both environmental conditions and ecological responses. Land managers need strategies to increase regional adaptive capacity, but relevant and rapid assessment approaches are...
Ultra-high resolution four dimensional geodetic imaging of engineered structures for stability assessment
Gerald W. Bawden, Sandra Bond, J. H. Podoski, O. Kreylos, L. H. Kellogg
2012, Conference Paper, GeoCongress 2012
We used ground-based Tripod LiDAR (T-LiDAR) to assess the stability of two engineered structures: a bridge spanning the San Andreas fault following the M6.0 Parkfield earthquake in Central California and a newly built coastal breakwater located at the Kaumālapa`u Harbor Lana'i, Hawaii. In the 10 weeks following the earthquake, we...
Geometry and subsidence history of the Dead Sea basin: A case for fluid-induced mid-crustal shear zone?
Uri S. ten Brink, C.H. Flores
2012, Journal of Geophysical Research B: Solid Earth (117)
Pull‐apart basins are narrow zones of crustal extension bounded by strike‐slip faults that can serve as analogs to the early stages of crustal rifting. We use seismic tomography, 2‐D ray tracing, gravity modeling, and subsidence analysis to study crustal extension of the Dead...
A method for physically based model analysis of conjunctive use in response to potential climate changes
R. T. Hanson, L. E. Flint, A. L. Flint, M. D. Dettinger, C.C. Faunt, D. Cayan, W. Schmid
2012, Water Resources Research (48)
Potential climate change effects on aspects of conjunctive management of water resources can be evaluated by linking climate models with fully integrated groundwater-surface water models. The objective of this study is to develop a modeling system that links global climate models with regional hydrologic models, using the California Central Valley...
Trophic cascades linking wolves (Canis lupus), coyotes (Canis latrans), and small mammals
B.J. Miller, H.J. Harlow, T.S. Harlow, D. Biggins, W. J. Ripple
2012, Canadian Journal of Zoology (90) 70-78
When large carnivores are extirpated from ecosystems that evolved with apex predators, these systems can change at the herbivore and plant trophic levels. Such changes across trophic levels are called cascading effects and they are very important to conservation. Studies on the effects of reintroduced wolves in Yellowstone National Park...
The effect of diagenesis and fluid migration on rare earth element distribution in pore fluids of the northern Cascadia accretionary margin
Ji-Hoon Kim, Marta E. Torres, Brian A. Haley, Miriam Kastner, John W. Pohlman, Michael Riedel, Young-Joo Lee
2012, Chemical Geology (291) 152-165
Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern...
Soil C and N patterns in a semiarid piñon-juniper woodland: Topography of slope and ephemeral channels add to canopy-intercanopy heterogeneity
Darin J. Law, David D. Breshears, Michael H. Ebinger, Clifton W. Meyer, Craig D. Allen
2012, Journal of Arid Environments (79) 20-24
Carbon and nitrogen are crucial to semiarid woodlands, determining decomposition, production and redistribution of water and nutrients. Carbon and nitrogen are often greater beneath canopies than intercanopies. Upslope vs. downslope position and ephemeral channels might also cause variation in C and N. Yet, few studies have simultaneously evaluated spatial variation...
Foraging segregation and genetic divergence between geographically proximate colonies of a highly mobile seabird
Anne E. Wiley, Andreanna J. Welch, P.H. Ostrom, Helen F. James, Craig A. Stricker, R.C. Fleischer, H. Gandhi, Josh Adams, D. G. Ainley, F. Duvall, N. Holmes, D. Hu, S. Judge, J. Penniman, K.A. Swindle
2012, Oecologia (168) 119-130
Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis)...
A newly discovered impact crater in Titan's Senkyo: Cassini VIMS observations and comparison with other impact features
B. J. Buratti, Christophe Sotin, K. Lawrence, R. H. Brown, Stéphane Le Mouélic, J.M. Soderblom, J. Barnes, Roger N. Clark, K. H. Baines, P. D. Nicholson
2012, Planetary and Space Science (60) 18-25
Senkyo is an equatorial plain on Titan filled with dunes and surrounded by hummocky plateaus. During the Titan targeted flyby T61 on August 25, 2009, the Cassini Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft observed a circular feature, centered at 5.4° N and 341°W, that superimposes the dune fields and a...
Intelligent estimation of spatially distributed soil physical properties
F. Iwashita, Michael J. Friedel, G.F. Ribeiro, Stephen J. Fraser
2012, Geoderma (170) 1-10
Spatial analysis of soil samples is often times not possible when measurements are limited in number or clustered. To obviate potential problems, we propose a new approach based on the self-organizing map (SOM) technique. This approach exploits underlying nonlinear relation of the steady-state geomorphic concave–convex nature of hillslopes (from hilltop...
Shade-grown coffee in Puerto Rico: Opportunities to preserve biodiversity while reinvigorating a struggling agricultural commodity
R. Borkhataria, Jaime A. Collazo, Martha J. Groom, A. Jordan-Garcia
2012, Agriculture, Ecosystems and Environment (149) 164-170
Shade-grown coffee contributes to biodiversity conservation and has many ecological benefits. We reviewed historical trends in coffee production and interviewed 100 coffee growers in 1999 to determine current management practices and attitudes toward the cultivation of sun and shade coffee in Puerto Rico. We discuss the outlook for the coffee...
Supplementing seed banks to rehabilitate disturbed Mojave Desert shrublands: Where do all the seeds go?
Lesley A. DeFalco, Todd Esque, Melissa B. Nicklas, Jeffrey M. Kane
2012, Restoration Ecology (20) 85-94
Revegetation of degraded arid lands often involves supplementing impoverished seed banks and improving the seedbed, yet these approaches frequently fail. To understand these failures, we tracked the fates of seeds for six shrub species that were broadcast across two contrasting surface disturbances common to the Mojave Desert—sites compacted by concentrated...
