Late Quaternary sedimentological and climate changes at Lake Bosumtwi Ghana: new constraints from laminae analysis and radiocarbon age modeling
Timothy M. Shanahan, J. Warren Beck, Jonathan T. Overpeck, Nicholas P. McKay, Jeffrey S. Pigati, John A. Peck, Christopher A. Scholz, Clifford W. Heil Jr., John W. King
2012, Palaeogeography, Palaeoclimatology, Palaeoecology (361-362) 49-60
The Lake Bosumtwi sediment record represents one of the longest and highest-resolution terrestrial records of paleoclimate change available from sub-Saharan Africa. Here we report a new sediment age model framework for the last ~ 45 cal kyr of sedimentation using a combination of high-resolution radiocarbon dating, Bayesian age-depth modeling and...
Holocene dune formation at Ash Meadows National Wildlife Area, Nevada, USA
Nicholas Lancaster, Shannon Mahan
2012, Quaternary Research (78) 266-274
Small isolated dune fields in the northern Mojave Desert are important centers of biodiversity and archaeological occupation sites. Currently dunes at Ash Meadows, Nevada, are stabilized by vegetation and are experiencing erosion of their upwind margins, indicating a negative sediment budget. New OSL ages from dunes at Ash Meadows indicate...
Emerging contaminants at a closed and an operating landfill in Oklahoma
William J. Andrews, Jason R. Masoner, Isabelle M. Cozzarelli
2012, Groundwater Monitoring & Remediation (32) 120-130
Landfills are the final depositories for a wide range of solid waste from both residential and commercial sources, and therefore have the potential to produce leachate containing many organic compounds found in consumer products such as pharmaceuticals, plasticizers, disinfectants, cleaning agents, fire retardants, flavorings, and preservatives, known as emerging contaminants...
Modeling responses of large-river fish populations to global climate change through downscaling and incorporation of predictive uncertainty
Mark L. Wildhaber, Christopher K. Wikle, Christopher J. Anderson, Kristie J. Franz, Edward H. Moran, Rima Dey
Helmut Mader, Julia Kraml, editor(s)
2012, Conference Paper, 9th International Symposium on Ecohydraulics 2012 Proceedings
Climate change operates over a broad range of spatial and temporal scales. Understanding its effects on ecosystems requires multi-scale models. For understanding effects on fish populations of riverine ecosystems, climate predicted by coarse-resolution Global Climate Models must be downscaled to Regional Climate Models to watersheds to river hydrology...
Characterization of previously unidentified lunar pyroclastic deposits using Lunar Reconnaissance Orbiter Camera (LROC) data
J. Olaf Gustafson, James F. Bell, Lisa R. Gaddis, B. Ray Hawke, Thomas A. Giguere
2012, Journal of Geophysical Research E: Planets (117)
We used a Lunar Reconnaissance Orbiter Camera (LROC) global monochrome Wide-angle Camera (WAC) mosaic to conduct a survey of the Moon to search for previously unidentified pyroclastic deposits. Promising locations were examined in detail using LROC multispectral WAC mosaics, high-resolution LROC Narrow Angle Camera (NAC) images, and Clementine multispectral (ultraviolet-visible...
Assessing consumption of bioactive micro-particles by filter-feeding Asian carp
Nathan R. Jensen, Jon J. Amberg, James A. Luoma, Liza R. Walleser, Mark P. Gaikowski
2012, Journal of Aquaculture Research & Development (3)
Silver carp Hypophthalmichthys molitrix (SVC) and bighead carp H. nobilis (BHC) have impacted waters in the US since their escape. Current chemical controls for aquatic nuisance species are non-selective. Development of a bioactive micro-particle that exploits filter-feeding habits of SVC or BHC could result in a new control tool. It...
Design and development of linked data from the National Map
E. Lynn Usery, Dalia E. Varanka
2012, Semantic Web (3) 371-384
The development of linked data on the World-Wide Web provides the opportunity for the U.S. Geological Survey (USGS) to supply its extensive volumes of geospatial data, information, and knowledge in a machine interpretable form and reach users and applications that heretofore have been unavailable. To pilot a process to take...
Dryland biological soil crust cyanobacteria show unexpected decreases in abundance under long-term elevated CO2
Blaire Steven, La Verne Gallegos-Graves, Chris M. Yeager, Jayne Belnap, R. David Evans, Cheryl R. Kuske
2012, Environmental Microbiology (14) 3247-3258
Biological soil crusts (biocrusts) cover soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in biocrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested...
Density-dependent nest predation in waterfowl: the relative importance of nest density versus nest dispersion
Joshua T. Ackerman, Kevin M. Ringelman, J.M. Eadie
2012, Oecologia (169) 695-702
When nest predation levels are very high or very low, the absolute range of observable nest success is constrained (a floor/ceiling effect), and it may be more difficult to detect density-dependent nest predation. Density-dependent nest predation may be more detectable in years with moderate predation rates, simply because there can...
Earthquake ground motion
Nicolas Luco, Michael Valley, C.B. Crouse
2012, Book chapter, 2009 NEHRP Recommended Seismic Provisions: Design Examples (FEMA P-751)
Most of the effort in seismic design of buildings and other structures is focused on structural design. This chapter addresses another key aspect of the design process—characterization of earthquake ground motion. Section 3.1 describes the basis of the earthquake ground motion maps in the Provisions and in ASCE 7. Section...
Improving PAGER's real-time earthquake casualty and loss estimation toolkit: a challenge
K. S. Jaiswal, D.J. Wald
2012, Conference Paper, The 15th World Conference on Earthquake Engineering: September 24-28, 2012, Lisbon, Portugal
We describe the on-going developments of PAGER’s loss estimation models, and discuss value-added web content that can be generated related to exposure, damage and loss outputs for a variety of PAGER users. These developments include identifying vulnerable building types in any given area, estimating earthquake-induced damage and loss statistics by...
Geomagnetic detection of the sectorial solar magnetic field and the historical peculiarity of minimum 23-24
Jeffrey J. Love, J. Rigler
2012, Geophysical Research Letters (39)
[1] Analysis is made of the geomagnetic-activityaaindex covering solar cycle 11 to the beginning of 24, 1868–2011. Autocorrelation shows 27.0-d recurrent geomagnetic activity that is well-known to be prominent during solar-cycle minima; some minima also exhibit a smaller amount of 13.5-d recurrence. Previous work has shown that the recent solar...
John B. "Jack" Townshend (1927-2012)
Jeffrey J. Love, Carol A. Finn
2012, Eos, Transactions, American Geophysical Union (93) 524-525
Jack Townshend, geophysicist and dedicated public servant, died on 13 August 2012 in Fairbanks, Alaska. He was 85. Jack's career with the federal government, most of it with the national magnetic observatory program, spanned more than six solar cycles of time, and he retired only days before his death. The...
Developing ShakeCast statistical fragility analysis framework for rapid post-earthquake assessment
K.-W. Lin, D.J. Wald
2012, Conference Paper, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon, Portugal, September 24-28
When an earthquake occurs, the U. S. Geological Survey (USGS) ShakeMap estimates the extent of potentially damaging shaking and provides overall information regarding the affected areas. The USGS ShakeCast system is a freely-available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users’...
Late Holocene earthquake history of the Brigham City segment of the Wasatch fault zone at the Hansen Canyon, Kotter Canyon, and Pearsons Canyon trench sites, Box Elder County, Utah
Christopher B. DuRoss, Stephen F. Personius, Anthony J. Crone, Greg N. McDonald, Richard W. Briggs
2012, Special Study 142
Of the five central segments of the Wasatch fault zone (WFZ) having evidence of recurrent Holocene surface-faulting earthquakes, the Brigham City segment (BCS) has the longest elapsed time since its most recent surface-faulting event (~2.1 kyr) compared to its mean recurrence time between events (~1.3 kyr). Thus, the BCS has...
Comparison of soil thickness in a zero-order basin in the Oregon Coast Range using a soil probe and electrical resistivity tomography
Michael S. Morse, Ning Lu, Jonathan W. Godt, André Revil, Jeffrey A. Coe
2012, Journal of Geotechnical and Geoenvironmental Engineering (138) 1470-1482
Accurate estimation of the soil thickness distribution in steepland drainage basins is essential for understanding ecosystem and subsurface response to infiltration. One important aspect of this characterization is assessing the heavy and antecedent rainfall conditions that lead to shallow landsliding. In this paper, we investigate the direct current (DC) resistivity...
Effects of climate change and population growth on the transboundary Santa Cruz aquifer
Christopher A. Scott, Sharon Megdal, Lucas Antonio Oroz, James Callegary, Prescott Vandervoet
2012, Climate Research (51) 159-170
The USA and Mexico have initiated comprehensive assessment of 4 of the 18 aquifers underlying their 3000 km border. Binational management of groundwater is not currently proposed. University and agency researchers plus USA and Mexican federal, state, and local agency staff have collaboratively identified key challenges facing the Santa Cruz...
Data quality of seismic records from the Tohoku, Japan earthquake as recorded across the Albuquerque Seismological Laboratory networks
A. T. Ringler, L.S. Gee, B. Marshall, C. R. Hutt, T. Storm
2012, Seismological Research Letters (83) 575-584
Great earthquakes recorded across modern digital seismographic networks, such as the recent Tohoku, Japan, earthquake on 11 March 2011 (Mw = 9.0), provide unique datasets that ultimately lead to a better understanding of the Earth's structure (e.g., Pesicek et al. 2008) and earthquake sources (e.g., Ammon et al. 2011). For...
Bulk rock composition and geochemistry of olivine-hosted melt inclusions in the Grey Porri Tuff and selected lavas of the Monte dei Porri volcano, Salina, Aeolian Islands, southern Italy
Angela L. Doherty, Robert J. Bodnar, Benedetto De Vivo, Wendy A. Bohrson, Harvey E. Belkin, Antonia Messina, Robert J. Tracy
2012, Central European Journal of Geosciences (4) 338-355
The Aeolian Islands are an arcuate chain of submarine seamounts and volcanic islands, lying just north of Sicily in southern Italy. The second largest of the islands, Salina, exhibits a wide range of compositional variation in its erupted products, from basaltic lavas to rhyolitic pumice. The Monte dei Porri eruptions...
Allowable levels of take for the trade in Nearctic songbirds
Fred A. Johnson, Matthew A.H. Walters, G. Scott Boomer
2012, Ecological Applications (22) 1114-1130
The take of Nearctic songbirds for the caged-bird trade is an important cultural and economic activity in Mexico, but its sustainability has been questioned. We relied on the theta-logistic population model to explore options for setting allowable levels of take for 11 species of passerines that were subject to legal...
2014 Update of the United States National Seismic Hazard Maps
M.D. Petersen, C.S. Mueller, K. M. Haller, M. Moschetti, S. C. Harmsen, E. H. Field, K.S. Rukstales, Y. Zeng, D. M. Perkins, P. Powers, S. Rezaeian, N. Luco, A. Olsen, R. Williams
2012, Conference Paper, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon, Portugal, September 24-28
The U.S. National Seismic Hazard Maps are revised every six years, corresponding with the update cycle of the International Building Code. These maps cover the conterminous U.S. and will be updated in 2014 using the best-available science that is obtained from colleagues at regional and topical workshops, which are convened...
Ecology of bison, elk, and vegetation in an arid ecosystem
Kathryn A. Schoenecker
2012, Thesis
Herbivory has profound effects on vegetation production and structure in many different plant communities. The influence of herbivory on plants and ultimately ecosystem processes is shaped by the types of plants consumed, the intensity of herbivory, the evolutionary history of grazing, and the availability of water and nutrients to plants....
The ICDP Snake River Geothermal Drilling Project: preliminary overview of borehole geophysics
Douglas R. Schmitt, Lee M. Liberty, James E. Kessler, Jochem Kuck, Randolph Kofman, Ross Bishop, John W. Shervais, James P. Evans, Duane E. Champion
2012, Geothermal Resources Council Transactions (36) 1017-1022
Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand the geothermal systems in three locations across the Snake River Plain with varying geological and hydrological structure. An extensive series of standard and specialized geophysical logs were obtained in each of the wells. Hydrogen-index neutron and γ-γ density...
Constraints on the history and topography of the Northeastern Sierra Nevada from a Neogene sedimentary basin in the Reno-Verdi area, Western Nevada
James Trexler, Patricia Cashman, Michael Cosca
2012, Geosphere (8) 548-561
Neogene (Miocene–Pliocene) sedimentary rocks of the northeastern Sierra Nevada were deposited in small basins that formed in response to volcanic and tectonic activity along the eastern margin of the Sierra. These strata record an early phase (ca. 11–10 Ma) of extension and rapid sedimentation of boulder conglomerates and debrites deposited...
Developing Vs30 site-condition maps by combining observations with geologic and topographic constraints
E.M. Thompson, D.J. Wald
2012, Conference Paper, The 15th World Conference on Earthquake Engineering: September 24-28, 2012, Lisbon, Portugal
Despite obvious limitations as a proxy for site amplification, the use of time-averaged shear-wave velocity over the top 30 m (VS30) remains widely practiced, most notably through its use as an explanatory variable in ground motion prediction equations (and thus hazard maps and ShakeMaps, among other applications). As such, we...
