Publications
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Normalized rare earth elements in water, sediments, and wine: identifying sources and environmental redox conditions Normalized rare earth elements in water, sediments, and wine: identifying sources and environmental redox conditions
The concentrations of the rare earth elements (REE) in surface waters and sediments, when normalized on an element-by-element basis to one of several rock standards and plotted versus atomic number, yield curves that reveal their partitioning between different sediment fractions and the sources of those fractions, for example, between terrestrial-derived lithogenous debris and seawater...
Authors
David Piper, Michael Bau
Use of multi-node wells in the Groundwater-Management Process of MODFLOW-2005 (GWM-2005) Use of multi-node wells in the Groundwater-Management Process of MODFLOW-2005 (GWM-2005)
Many groundwater wells are open to multiple aquifers or to multiple intervals within a single aquifer. These types of wells can be represented in numerical simulations of groundwater flow by use of the Multi-Node Well (MNW) Packages developed for the U.S. Geological Survey’s MODFLOW model. However, previous versions of the Groundwater-Management (GWM) Process for MODFLOW did not allow...
Authors
David Ahlfeld, Paul Barlow
Steady rotation of the Cascade arc Steady rotation of the Cascade arc
Displacement of the Miocene Cascade volcanic arc (northwestern North America) from the active arc is in the same sense and at nearly the same rate as the present clockwise block motions calculated from GPS velocities in a North American reference frame. Migration of the ancestral arc over the past 16 m.y. can be explained by clockwise rotation of upper-plate blocks at 1.0°/m.y. over a...
Authors
Ray E. Wells, Robert McCaffrey
Onset of deglacial warming in West Antarctica driven by local orbital forcing Onset of deglacial warming in West Antarctica driven by local orbital forcing
The cause of warming in the Southern Hemisphere during the most recent deglaciation remains a matter of debate. Hypotheses for a Northern Hemisphere trigger, through oceanic redistributions of heat, are based in part on the abrupt onset of warming seen in East Antarctic ice cores and dated to 18,000 years ago, which is several thousand years after high-latitude Northern Hemisphere summer
Authors
WAIS Members, T. Fudge, Eric Steig, Bradley R. Markle, Spruce Schoenemann, Qinghua Ding, Kendrick Taylor, Joseph R. McConnell, Edward Brook, Todd Sowers, James White, Richard Alley, Hai Cheng, Gary Clow, Jihong Cole-Dai, Howard Conway, Kurt Cuffey, Jon Edwards, R. Edwards, Ross Edwards, John M. Fegyveresi, David Ferris, Joan Fitzpatrick, Jay Johnson, Geoffrey Hargreaves, James E. Lee, Olivia Maselli, William Mason, Kenneth McGwire, Logan Mitchell, Nicolai Mortensen, Peter Neff, Anais Orsi, Trevor Popp, Andrew Schauer, Jeffrey Severinghaus, Michael Sigl, Matthew Spencer, Bruce Vaughn, Donald Voigt, Edwin Waddington, Xianfeng Wang, Gifford Wong
Geologic map of the Lead Mountain 15’ quadrangle, San Bernardino County, California Geologic map of the Lead Mountain 15’ quadrangle, San Bernardino County, California
The Lead Mountain 15’ quadrangle in the Mojave Desert contains a record of Jurassic, Cretaceous, Tertiary, and Quaternary magmatism. Small amounts of Mesoproterozoic(?) augen gneiss and Paleozoic and Mesozoic(?) metasedimentary rocks are preserved in small patches; they are intruded by voluminous Jurassic plutons of quartz diorite to granite composition and by Late Cretaceous granite of...
Authors
Keith Howard, Keith Jagiello, Todd Fitzgibbon, Barbara John
Documentation of the seawater intrusion (SWI2) package for MODFLOW Documentation of the seawater intrusion (SWI2) package for MODFLOW
The SWI2 Package is the latest release of the Seawater Intrusion (SWI) Package for MODFLOW. The SWI2 Package allows three-dimensional vertically integrated variable-density groundwater flow and seawater intrusion in coastal multiaquifer systems to be simulated using MODFLOW-2005. Vertically integrated variable-density groundwater flow is based on the Dupuit approximation in which an...
Authors
Mark Bakker, Frans Schaars, Joseph Hughes, Christian Langevin, Alyssa M. Dausman
An application of Social Values for Ecosystem Services (SolVES) to three national forests in Colorado and Wyoming An application of Social Values for Ecosystem Services (SolVES) to three national forests in Colorado and Wyoming
Despite widespread recognition that social-value information is needed to inform stakeholders and decision makers regarding trade-offs in environmental management, it too often remains absent from ecosystem service assessments. Although quantitative indicators of social values need to be explicitly accounted for in the decision-making process, they need not be monetary. Ongoing efforts...
Authors
Benson Sherrouse, Darius Semmens, Jessica Clement
Simulated impacts of mountain pine beetle and wildfire disturbances on forest vegetation composition and carbon stocks in the Southern Rocky Mountains Simulated impacts of mountain pine beetle and wildfire disturbances on forest vegetation composition and carbon stocks in the Southern Rocky Mountains
Forests play an important role in sequestering carbon and offsetting anthropogenic greenhouse gas emissions, but changing disturbance regimes may compromise the capability of forests to store carbon. In the Southern Rocky Mountains, a recent outbreak of mountain pine beetle (Dendroctonus ponderosae; MPB) has caused levels of tree mortality that are unprecedented in recorded history. To...
Authors
Megan Caldwell, Todd Hawbaker, Jenny Briggs, P.W. Cigan, Susan Stitt
Geochronologic and geochemical data from Mesozoic rocks in the Black Mountain area northeast of Victorville, San Bernardino County, California Geochronologic and geochemical data from Mesozoic rocks in the Black Mountain area northeast of Victorville, San Bernardino County, California
We present geochronologic and geochemical data for Mesozoic rocks in the Black Mountain area northeast of Victorville, California, to supplement previous geologic mapping. These data, together with previously published results, limit the depositional age of the sedimentary Fairview Valley Formation to Early Jurassic, refine the ages and chemical compositions of selected units in the...
Authors
Paul Stone, Andrew Barth, Joseph L. Wooden, Nicole Fohey-Breting, Jorge Vazquez, Susan Priest
By
Geology, Energy, and Minerals Mission Area, Volcano Hazards Program, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Volcano Science Center, Geology, Minerals, Energy, and Geophysics Science Center
Water resources: Implications of changes in temperature and precipitation: Chapter 3 Water resources: Implications of changes in temperature and precipitation: Chapter 3
No abstract available.
Authors
Rick R. Raymondi, Jennifer Cuhaciyan, Patty Glick, Susan Capalbo, Laurie Houston, Sarah Shafer, Oliver Grah
Controls on recent Alaskan lake changes identified from water isotopes and remote sensing Controls on recent Alaskan lake changes identified from water isotopes and remote sensing
High-latitude lakes are important for terrestrial carbon dynamics and waterfowl habitat driving a need to better understand controls on lake area changes. To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate remotely sensed imagery with lake water isotope compositions and...
Authors
Lesleigh Anderson, Jean Birks, Jennifer Rover, Nikki Guldager
Tourism values for Mexican free-tailed bat (Tadarida brasiliensis mexicana) viewing Tourism values for Mexican free-tailed bat (Tadarida brasiliensis mexicana) viewing
Migratory species provide diverse ecosystem services to people, but these values have seldom been estimated rangewide for a single species. In this article, we summarize visitation and consumer surplus for recreational visitors to viewing sites for the Mexican free-tailed bat (Tadarida brasiliensis mexicana) throughout the Southwestern United States. Public bat viewing opportunities are...
Authors
Kenneth Bagstad, Ruscena Widerholdt