Nonlinear site response in medium magnitude earthquakes near Parkfield, California
Justin L. Rubinstein
2011, Bulletin of the Seismological Society of America (101) 275-286
Careful analysis of strong-motion recordings of 13 medium magnitude earthquakes (3.7 ≤ M ≤ 6.5) in the Parkfield, California, area shows that very modest levels of shaking (approximately 3.5% of the acceleration of gravity) can produce observable changes in site response. Specifically, I observe a drop and subsequent recovery of...
Geology and petroleum potential of the Arctic Alaska petroleum province
Kenneth J. Bird, David W. Houseknecht
2011, Geological Society Memoir 485-499
The Arctic Alaska petroleum province encompasses all lands and adjacent continental shelf areas north of the Brooks Range–Herald Arch orogenic belt and south of the northern (outboard) margin of the Beaufort Rift shoulder. Even though only a small part is thoroughly explored, it is one of the most prolific petroleum...
Salvage logging versus the use of burnt wood as a nurse object to promote post-fire tree seedling establishment
J. Castro, Craig D. Allen, M. Molina-Morales, Sara Maranon-Jimenez, A. Sanchez-Miranda, R. Zamora
2011, Restoration Ecology (19) 537-544
Intense debate surrounds the effects of post-fire salvage logging (SL) versus nonintervention policies on forest regeneration, but scant support is available from experimental studies. We analyze the effect of three post-fire management treatments on the recruitment of a serotinous pine (Pinus pinaster) at a Mediterranean mountain. Treatments were applied 7...
Effects of slow recovery rates on water column geochemistry in aquitard wells
K. E. Schilling
2011, Applied Geochemistry (26) 1108-1114
Monitoring wells are often installed in aquitards to verify effectiveness for preventing migration of surface contaminants to underlying aquifers. However, water sampling of aquitard wells presents a challenge due to the slow recovery times for water recharging the wells, which can take as long as weeks, months or years to...
Habitat fragmentation reduces nest survival in an Afrotropical bird community in a biodiversity hotspot
W.D. Newmark, T.R. Stanley
2011, Proceedings of the National Academy of Sciences of the United States of America (108) 11488-11493
Ecologists have long hypothesized that fragmentation of tropical landscapes reduces avian nest success. However, this hypothesis has not been rigorously assessed because of the difficulty of finding large numbers of well-hidden nests in tropical forests. Here we report that in the East Usambara Mountains in Tanzania, which are part of...
Complex dynamics at the interface between wild and domestic viruses of finfish
Gael Kurath, J. Winton
2011, Current Opinion in Virology (1) 73-80
Viral traffic occurs readily between wild and domesticated stocks of finfish because aquatic environments have greater connectivity than their terrestrial counterparts and because the global expansion and dynamic nature of intensive aquaculture provide multiple pathways of transmission and unique drivers of virus adaptation. Supported by examples from the literature, we...
Location and agricultural practices influence spring use of harvested cornfields by cranes and geese in Nebraska
Michael J. Anteau, Mark H. Sherfy, A.A. Bishop
2011, Journal of Wildlife Management (75) 1004-1011
Millions of ducks, geese, and sandhill cranes (Grus canadensis; hereafter cranes) stop in the Central Platte River Valley (CPRV) of Nebraska to store nutrients for migration and reproduction by consuming corn remaining in fields after harvest. We examined factors that influence use of cornfields by cranes and geese (all mid‐continent...
High-resolution three-dimensional imaging and analysis of rock falls in Yosemite valley, California
Gregory M. Stock, Gerald W. Bawden, J.K. Green, E. Hanson, G. Downing, Brian D. Collins, Sandra Bond, M. Leslar
2011, Geosphere (7) 573-581
We present quantitative analyses of recent large rock falls in Yosemite Valley, California, using integrated high-resolution imaging techniques. Rock falls commonly occur from the glacially sculpted granitic walls of Yosemite Valley, modifying this iconic landscape but also posing significant potential hazards and risks. Two large rock falls occurred from the...
The characteristics of gas hydrates recovered from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope
H. Lu, Thomas Lorenson, I.L. Moudrakovski, J.A. Ripmeester, Timothy S. Collett, R.B. Hunter, C.I. Ratcliffe
2011, Marine and Petroleum Geology (28) 411-418
Systematic analyses have been carried out on two gas hydrate-bearing sediment core samples, HYPV4, which was preserved by CH4 gas pressurization, and HYLN7, which was preserved in liquid-nitrogen, recovered from the BPXA-DOE-USGS Mount Elbert Stratigraphic Test Well. Gas hydrate in the studied core samples was found by observation to have developed...
Development and application of a pollen-based paleohydrologic reconstruction from the lower Roanoke River Basin, North Carolina, USA
D. Willard, C. Bernhardt, R. Brown, B. Landacre, P. Townsend
2011, The Holocene (21) 305-317
We used pollen assemblages to reconstruct late-Holocene paleohydrologic patterns in floodplain deposits from the lower Roanoke River basin (North Carolina, southeastern USA). Using 120 surface samples from 38 transects, we documented statistical relationships between pollen assemblages, vegetation, and landforms. Backswamp pollen assemblages (long hydroperiods) are dominated by Nyssa (tupelo) and...
Co-occurrence patterns of trees along macro-climatic gradients and their potential influence on the present and future distribution of Fagus sylvatica L.
E.S. Meier, Thomas C. Edwards Jr., Felix Kienast, M. Dobbertin, N.E. Zimmermann
2011, Journal of Biogeography (38) 371-382
During recent and future climate change, shifts in large-scale species ranges are expected due to the hypothesized major role of climatic factors in regulating species distributions. The stress-gradient hypothesis suggests that biotic interactions may act as major constraints on species distributions under more favourable growing conditions, while climatic constraints may...
Documenting channel features associated with gas hydrates in the Krishna-Godavari Basin, offshore India
M. Riedel, Timothy S. Collett, Ude Shankar
2011, Marine Geology (279) 1-11
During the India National Gas Hydrate Program (NGHP) Expedition 01 in 2006 significant sand and gas hydrate were recovered at Site NGHP-01-15 within the Krishna–Godavari Basin, East Coast off India. At the drill site NGHP-01-15, a 5–8 m thick interval was found that is characterized by higher sand content than anywhere...
High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry
J.L.L. Morgan, G.W. Gordon, R.C. Arrua, J.L. Skulan, A.D. Anbar, T.D. Bullen
2011, Analytical Chemistry (83) 6956-6962
We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity...
A Digital Hydrologic Network Supporting NAWQA MRB SPARROW Modeling--MRB_E2RF1
J. W. Brakebill, S.E. Terziotti
2011, Report
A digital hydrologic network was developed to support SPAtially Referenced Regression on Watershed attributes (SPARROW) models within selected regions of the United States. These regions correspond with the U.S. Geological Survey's National Water Quality Assessment (NAWQA) Program Major River Basin (MRB) study units 2, 3, 4, 5, and 7 (Preston...
Q is for quartz
W. H. Langer
2011, Aggregates Manager (16) 36-36
This versatile mineral has been used in everything from ceremonial rattles to sonar transducers to quartz watches....
Rising sea level may cause decline of fringing coral reefs
Michael E. Field, Andrea S. Ogston, Curt D. Storlazzi
2011, Eos, Transactions, American Geophysical Union (92) 273-274
Coral reefs are major marine ecosystems and critical resources for marine diversity and fisheries. These ecosystems are widely recognized to be at risk from a number of stressors, and added to those in the past several decades is climate change due to anthropogenically driven increases in atmospheric concentrations of greenhouse...
Volcanism on Io: New insights from global geologic mapping
David A. Williams, Laszlo P. Keszthelyi, David A. Crown, Jessica A. Yff, Windy L. Jaeger, Paul M. Schenk, Paul E. Geissler, Tammy L. Becker
2011, Icarus (214) 91-112
We produced the first complete, 1:15 M-scale global geologic map of Jupiter’s moon Io, based on a set of monochrome and color Galileo–Voyager image mosaics produced at a spatial resolution of 1 km/pixel. The surface of Io was mapped into 19 units based on albedo, color and surface morphology, and is subdivided as follows:...
Setting limits: Using air pollution thresholds to protect and restore U.S. ecosystems
M.E. Fenn, K.F. Lambert, T.F. Blett, Douglas A. Burns, L.H. Pardo, Gary M. Lovett, R. A. Haeuber, D.C. Evers, C. T. Driscoll, D.S. Jeffries
2011, Issues in Ecology
More than four decades of research provide unequivocal evidence that sulfur, nitrogen, and mercury pollution have altered, and will continue to alter, our nation's lands and waters. The emission and deposition of air pollutants harm native plants and animals, degrade water quality, affect forest productivity, and are damaging to human...
Active channel for Fanno Creek, Oregon
Steven Sobieszczyk
2011, Report
Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the active, wetted channel as...
GAGES-II: Geospatial Attributes of Gages for Evaluating Streamflow
James A. Falcone
2011, Report
This dataset, termed "GAGES II", an acronym for Geospatial Attributes of Gages for Evaluating Streamflow, version II, provides geospatial data and classifications for 9,322 stream gages maintained by the U.S. Geological Survey (USGS). It is an update to the original GAGES, which was published as a Data Paper on the...
Water sample locations for Fanno Creek, Oregon
Steven Sobieszczyk
2011, Report
Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the locations where water-quality samples...
Geomorphic floodplain with organic matter (biomass) estimates for Fanno Creek, Oregon
Steven Sobieszczyk
2011, Report
Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the geomorphic floodplain as derived...
Stream Centerline for Fanno Creek, Oregon
Steven Sobieszczyk
2011, Report
Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the stream centerline of the...
Land cover classification for Fanno Creek, Oregon
Steven Sobieszczyk
2011, Report
Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the floodplain land cover as...
Solid sample locations for Fanno Creek, Oregon
Steven Sobieszczyk
2011, Report
Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the locations where solid samples...
