Aeolian nutrient fluxes following wildfire in sagebrush steppe: Implications for soil carbon storage
N.J. Hasselquist, M.J. Germino, J.B. Sankey, L.J. Ingram, N.F. Glenn
2011, Biogeosciences (8) 3649-3659
Pulses of aeolian transport following fire can profoundly affect the biogeochemical cycling of nutrients in semi-arid and arid ecosystems. Our objective was to determine horizontal nutrient fluxes occurring in the saltation zone during an episodic pulse of aeolian transport that occurred following a wildfire in a semi-arid sagebrush steppe ecosystem...
Pseudospectral modeling and dispersion analysis of Rayleigh waves in viscoelastic media
K. Zhang, Y. Luo, J. Xia, C. Chen
2011, Soil Dynamics and Earthquake Engineering (31) 1332-1337
Multichannel Analysis of Surface Waves (MASW) is one of the most widely used techniques in environmental and engineering geophysics to determine shear-wave velocities and dynamic properties, which is based on the elastic layered system theory. Wave propagation in the Earth, however, has been recognized as viscoelastic and the propagation of...
The flow dynamics of an extremely large volume pyroclastic flow, the 2.08-Ma Cerro Galán Ignimbrite, NW Argentina, and comparison with other flow types
Ray A.F. Cas, Heather M. Wright, Christopher B. Folkes, Chiara Lesti, Massimiliano Porreca, Guido Giordano, Jose G. Viramonte
2011, Bulletin of Volcanology (73) 1583-1609
The 2.08-Ma Cerro Galán Ignimbrite (CGI) represents a >630-km3 dense rock equivalent (VEI 8) eruption from the long-lived Cerro Galán magma system (∼6 Ma). It is a crystal-rich (35–60%), pumice (<10% generally) and lithic-poor (<5% generally) rhyodacitic ignimbrite, lacking a preceding plinian fallout deposit. The CGI is preserved up to 80 km...
Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States
L.H. Pardo, M.E. Fenn, C.L. Goodale, L.H. Geiser, C. T. Driscoll, E.B. Allen, Jill Baron, R. Bobbink, W.D. Bowman, C.M. Clark, B. Emmett, F.S. Gilliam, T.L. Greaver, S.J. Hall, E.A. Lilleskov, L. Liu, J.A. Lynch, K.J. Nadelhoffer, S.S. Perakis, M. J. Robin-Abbott, J.L. Stoddard, K.C. Weathers, R.L. Dennis
2011, Ecological Applications (21) 3049-3082
Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for...
Long-term change in perennial vegetation along the Colorado river in Grand Canyon national park (1889-2010)
R. H. Webb, Jayne Belnap, M. L. Scott, Todd Esque
2011, Park Science (28) 83-87
Long-term monitoring data are difficult to obtain for high-value resource areas, particularly in remote parts of national parks. One long-used method for evaluating change uses ground-based repeat photography to match historical images of landscapes. River expeditions that documented a proposed railroad route through Grand Canyon with large-format photographs occurred in...
Mountain treelines: A roadmap for research orientation
George P. Malanson, Lynn M. Resler, Maaike Y. Bader, Fredrich-Karl Holtmeier, David R. Butler, Daniel J. Weiss, Lori D. Daniels, Daniel B. Fagre
2011, Arctic, Antarctic, and Alpine Research (43) 167-177
For over 100 years, mountain treelines have been the subject of varied research endeavors and remain a strong area of investigation. The purpose of this paper is to examine aspects of the epistemology of mountain treeline research-that is, to investigate how knowledge on treelines has been acquired and the changes...
Zircon-scale insights into the history of a Supervolcano, Bishop Tuff, Long Valley, California, with implications for the Ti-in-zircon geothermometer
M. R. Reid, J.A. Vazquez, A.K. Schmitt
2011, Contributions to Mineralogy and Petrology (161) 293-311
Zircon has the outstanding capacity to record chronological, thermal, and chemical information, including the storage history of zoned silicic magma reservoirs like the one responsible for the Bishop Tuff of eastern California, USA. Our novel ion microprobe approach reveals that Bishop zircon rims with diverse chemical characteristics surround intermediate domains...
Modeling PSInSAR time series without phase unwrapping
L. Zhang, X. Ding, Z. Lu
2011, IEEE Transactions on Geoscience and Remote Sensing (49) 547-556
In this paper, we propose a least-squares-based method for multitemporal synthetic aperture radar interferometry that allows one to estimate deformations without the need of phase unwrapping. The method utilizes a series of multimaster wrapped differential interferograms with short baselines and focuses on arcs at which there are no phase ambiguities....
Historical trends of hypoxia in Changjiang River estuary: Applications of chemical biomarkers and microfossils
X. Li, T.S. Bianchi, Z. Yang, L.E. Osterman, M. A. Allison, Steven F. DiMarco, G. Yang
2011, Journal of Marine Systems (86) 57-68
Over the past two decades China has become the largest global consumer of fertilizers, which has enhanced river nutrient fluxes and caused eutrophication and hypoxia in the Yangtze (Changjiang) large river delta-front estuary (LDE). In this study, we utilized plant pigments, lignin-phenols, stable isotopes (δ13C and δ15N) and foraminiferal microfossils...
Classification of Thermal Patterns at Karst Springs and Cave Streams
A.J. Luhmann, M.D. Covington, Albert J. Peters, S.C. Alexander, C.T. Anger, J.A. Green, Anthony C. Runkel, E.C. Alexander
2011, Ground Water (49) 324-335
Thermal patterns of karst springs and cave streams provide potentially useful information concerning aquifer geometry and recharge. Temperature monitoring at 25 springs and cave streams in southeastern Minnesota has shown four distinct thermal patterns. These patterns can be divided into two types: those produced by flow paths with ineffective heat...
Projected changes to growth and mortality of Hawaiian corals over the next 100 years
R.K. Hoeke, P. L. Jokiel, R. W. Buddemeier, R.E. Brainard
2011, PLoS ONE (6)
Background: Recent reviews suggest that the warming and acidification of ocean surface waters predicated by most accepted climate projections will lead to mass mortality and declining calcification rates of reef-building corals. This study investigates the use of modeling techniques to quantitatively examine rates of coral cover change due to these...
Viruses and bacteria in karst and fractured rock aquifers in east Tennessee, USA
T.B. Johnson, L.D. McKay, A.C. Layton, S.W. Jones, G.C. Johnson, J.L. Cashdollar, D.R. Dahling, L.F. Villegas, G.S. Fout, D.E. Williams, G. Sayler
2011, Ground Water (49) 98-110
A survey of enteric viruses and indicator bacteria was carried out in eight community water supply sources (four wells and four springs) in East Tennessee. Seven sites derived their water from carbonate aquifers and one from fractured sandstone. Four of the sites were deemed "low-risk" based on prior monitoring of...
Toward a consistent model for strain accrual and release for the New Madrid Seismic Zone, central United States
S. E. Hough, M. Page
2011, Journal of Geophysical Research B: Solid Earth (116)
At the heart of the conundrum of seismogenesis in the New Madrid Seismic Zone is the apparently substantial discrepancy between low strain rate and high recent seismic moment release. In this study we revisit the magnitudes of the four principal 1811–1812 earthquakes using intensity values determined from individual assessments from...
8 March 2010 Elazığ-Kovancilar (Turkey) Earthquake: observations on ground motions and building damage
Sinan Akkar, A. Aldemir, A. Askan, S. Bakir, E. Canbay, I.O. Demirel, M.A. Erberik, Z. Gulerce, Polat Gulkan, Erol Kalkan, S. Prakash, M.A. Sandikkaya, V. Sevilgen, B. Ugurhan, E. Yenier
2011, Seismological Research Letters (82) 42-58
An earthquake of MW = 6.1 occurred in the Elazığ region of eastern Turkey on 8 March 2010 at 02:32:34 UTC. The United States Geological Survey (USGS) reported the epicenter of the earthquake as 38.873°N-39.981°E with a focal depth of 12 km. Forty-two people lost their lives and 137 were injured during...
Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry
K. Mursula, E. Tanskanen, J.J. Love
2011, Geophysical Research Letters (38)
We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993–2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total...
Estimating equivalence with quantile regression
B.S. Cade
2011, Ecological Applications (21) 281-289
Equivalence testing and corresponding confidence interval estimates are used to provide more enlightened statistical statements about parameter estimates by relating them to intervals of effect sizes deemed to be of scientific or practical importance rather than just to an effect size of zero. Equivalence tests and confidence interval estimates are...
Mapping irrigated areas of Ghana using fusion of 30 m and 250 m resolution remote-sensing data
M.K. Gumma, P.S. Thenkabail, F. Hideto, A. Nelson, V. Dheeravath, D. Busia, A. Rala
2011, Remote Sensing (3) 816-835
Maps of irrigated areas are essential for Ghana's agricultural development. The goal of this research was to map irrigated agricultural areas and explain methods and protocols using remote sensing. Landsat Enhanced Thematic Mapper (ETM+) data and time-series Moderate Resolution Imaging Spectroradiometer (MODIS) data were used to map irrigated agricultural areas...
Comparison of phenolic compounds and the effects of invasive and native species in East Asia: Support for the novel weapons hypothesis
Y.-O. Kim, E.J. Lee
2011, Ecological Research (26) 87-94
One prediction of the novel weapons hypothesis (NWH) for the dominance of exotic invasive plant species is that the allelopathic effects of successful invaders will, in general, be more biochemically inhibitory to native species and microbes in invaded regions than the native plants themselves. However, no study has compared biochemical...
Trench infiltration for managed aquifer recharge to permeable bedrock
V.M. Heilweil, D.E. Watt
2011, Hydrological Processes (25) 141-151
Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge...
Alphacoronaviruses in new World bats: Prevalence, persistence, phylogeny, and potential for interaction with humans
C. Osborne, P.M. Cryan, T. J. O'Shea, L.M. Oko, C. Ndaluka, C.H. Calisher, A.D. Berglund, M.L. Klavetter, R. A. Bowen, K.V. Holmes, S.R. Dominguez
2011, PLoS ONE (6) 1-11
Bats are reservoirs for many different coronaviruses (CoVs) as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4...
Mg-spinel lithology: A new rock type on the lunar farside
C.M. Pieters, S. Besse, J. Boardman, B. Buratti, L. Cheek, R. N. Clark, J. #NAME? Combe, D. Dhingra, J.N. Goswami, R.O. Green, J.W. Head, P. Isaacson, R. Klima, G. Kramer, S. Lundeen, E. Malaret, T. McCord, J. Mustard, J. Nettles, N. Petro, C. Runyon, M. Staid, J. Sunshine, L.A. Taylor, K. Thaisen, S. Tompkins, J. Whitten
2011, Journal of Geophysical Research E: Planets (116)
High-resolution compositional data from Moon Mineralogy Mapper (M 3) for the Moscoviense region on the lunar farside reveal three unusual, but distinctive, rock types along the inner basin ring. These are designated "OOS" since they are dominated by high concentrations of orthopyroxene, olivine, and Mg-rich spinel, respectively. The OOS occur...
High hunting pressure selects for earlier birth date: Wild boar as a case study
M. Gamelon, A. Besnard, J.-M. Gaillard, S. Servanty, E. Baubet, S. Brandt, O. Gimenez
2011, Evolution (65) 3100-3112
Exploitation by humans affects the size and structure of populations. This has evolutionary and demographic consequences that have typically being studied independent of one another. We here applied a framework recently developed applying quantitative tools from population ecology and selection gradient analysis to quantify the selection on a quantitative trait-birth...
Movements of wolves at the northern extreme of the species' range, including during four months of darkness
L.D. Mech, H.D. Cluff
2011, PLoS ONE (6)
Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (<75??N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching -53 C. The extent to which...
Geological effects and implications of the 2010 tsunami along the central coast of Chile
R.A. Morton, G. Gelfenbaum, M.L. Buckley, B. M. Richmond
2011, Sedimentary Geology (242) 34-51
Geological effects of the 2010 Chilean tsunami were quantified at five near-field sites along a 200 km segment of coast located between the two zones of predominant fault slip. Field measurements, including topography, flow depths, flow directions, scour depths, and deposit thicknesses, provide insights into the processes and morphological changes associated...
Epistemic uncertainty in California-wide synthetic seismicity simulations
F. F. Pollitz
2011, Bulletin of the Seismological Society of America (101) 2481-2498
The generation of seismicity catalogs on synthetic fault networks holds the promise of providing key inputs into probabilistic seismic-hazard analysis, for example, the coefficient of variation, mean recurrence time as a function of magnitude, the probability of fault-to-fault ruptures, and conditional probabilities for foreshock-mainshock triggering. I employ a seismicity simulator...
