Fortnightly modulation of San Andreas tremor and low-frequency earthquakes
Nicholas van der Elst, Andrew Delorey, David R. Shelly, Paul Johnson
2016, Proceedings of the National Academy of Sciences (113) 8601-8605
Earth tides modulate tremor and low-frequency earthquakes (LFEs) on faults in the vicinity of the brittle−ductile (seismic−aseismic) transition. The response to the tidal stress carries otherwise inaccessible information about fault strength and rheology. Here, we analyze the LFE response to the fortnightly tide, which modulates the amplitude of the daily...
Does resolution of flow field observation influence apparent habitat use and energy expenditure in juvenile coho salmon?
Desiree D. Tullos, Cara Walter, Jason B. Dunham
2016, Water Resources Research (52) 5938-5950
This study investigated how the resolution of observation influences interpretation of how fish, juvenile Coho Salmon (Oncorhynchus kisutch), exploit the hydraulic environment in streams. Our objectives were to evaluate how spatial resolution of the flow field observation influenced: (1) the velocities considered to be representative of habitat units; (2) patterns...
Comparisons between vs30 and spectral response for 30 sites in Newcastle, Australia from collocated seismic cone penetrometer, active- and passive-source vs data
Theodora Volti, David Burbidge, Clive Collins, Michael W. Asten, Jackson K. Odum, William J. Stephenson, Chris Pascal, Josef Holzschuh
2016, Bulletin of the Seismological Society of America (106) 1690-1709
Although the time‐averaged shear‐wave velocity down to 30 m depth (VS30) can be a proxy for estimating earthquake ground‐motion amplification, significant controversy exists about its limitations when used as a single parameter for the prediction of amplification. To examine this question in absence of relevant strong‐motion records, we use a range...
Structured decision making for managing pneumonia epizootics in bighorn sheep
Sarah N. Sells, Michael S. Mitchell, Victoria L. Edwards, Justin A. Gude, Neil J. Anderson
2016, Journal of Wildlife Management (80) 957-969
Good decision-making is essential to conserving wildlife populations. Although there may be multiple ways to address a problem, perfect solutions rarely exist. Managers are therefore tasked with identifying decisions that will best achieve desired outcomes. Structured decision making (SDM) is a method of decision analysis used to identify the most...
The road to NHDPlus — Advancements in digital stream networks and associated catchments
Richard B. Moore, Thomas A. Dewald
2016, Journal of the American Water Resources Association (52) 890-900
A progression of advancements in Geographic Information Systems techniques for hydrologic network and associated catchment delineation has led to the production of the National Hydrography Dataset Plus (NHDPlus). NHDPlus is a digital stream network for hydrologic modeling with catchments and a suite of related geospatial data. Digital stream networks with...
Landscape effects of wildfire on permafrost distribution in interior Alaska derived from remote sensing
Dana R. N. Brown, M. Torre Jorgenson, Knut Kielland, David L. Verbyla, Anupma Prakash, Joshua C. Koch
2016, Remote Sensing (8) 1-22
Climate change coupled with an intensifying wildfire regime is becoming an important driver of permafrost loss and ecosystem change in the northern boreal forest. There is a growing need to understand the effects of fire on the spatial distribution of permafrost and its associated ecological consequences. We focus on the...
Carbon and energy fluxes in cropland ecosystems: a model-data comparison
E. Lokupitiya, A. Scott Denning, K. Schaefer, D. Ricciuto, R. Anderson, M. A. Arain, I. Baker, A. G. Barr, G. Chen, J.M. Chen, P. Ciais, D.R. Cook, M.C. Dietze, M. El Maayar, M. Fischer, R. Grant, D. Hollinger, C. Izaurralde, A. Jain, C.J. Kucharik, Z. Li, S. Liu, L. Li, R. Matamala, P. Peylin, D. Price, S. W. Running, A. Sahoo, M. Sprintsin, A.E. Suyker, H. Tian, Christina Tonitto, M.S. Torn, Hans Verbeeck, S.B. Verma, Y. Xue
2016, Biogeochemistry (128) 53-76
Croplands are highly productive ecosystems that contribute to land–atmosphere exchange of carbon, energy, and water during their short growing seasons. We evaluated and compared net ecosystem exchange (NEE), latent heat flux (LE), and sensible heat flux (H) simulated by a suite of ecosystem models at five agricultural eddy covariance flux...
Seasonal movements and habitat use of Potamodromous Rainbow Trout across a complex Alaska riverscape
Kevin M. Fraley, Jeffrey A. Falke, Richard Yanusz, Sam S. Ivey
2016, Transactions of the American Fisheries Society (145) 1077-1092
Potamodromous Rainbow Trout Oncorhynchus mykiss are an important ecological and recreational resource in freshwater ecosystems of Alaska, and increased human development, hydroelectric projects, and reduced escapement of Chinook Salmon Oncorhynchus tshawytscha may threaten their populations. We used aerial and on-the-ground telemetry tracking, a digital landscape model, and resource selection functions...
Advancing environmental flow science: Developing frameworks for altered landscapes and integrating efforts across disciplines.
Shannon K. Brewer, Ryan A. McManamay, Andrew D. Miller, Robert Mollenhauer, Thomas A. Worthington, Tom Arsuffi
2016, Environmental Management (58) 175-192
Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing approaches...
Complex explosive volcanic activity on the Moon within Oppenheimer crater
Kristen A Bennett, Briony H. N. Horgan, Lisa R. Gaddis, Benjamin T Greenhagen, Carlton C. Allen, Paul O. Hayne, James F. Bell, David A. Paige
2016, Icarus (273) 296-314
Oppenheimer Crater is a floor-fractured crater located within the South Pole-Aitken basin on the Moon, and exhibits more than a dozen localized pyroclastic deposits associated with the fractures. Localized pyroclastic volcanism on the Moon is thought to form as a result of intermittently explosive Vulcanian eruptions under low effusion rates,...
On the deterministic and stochastic use of hydrologic models
William H. Farmer, Richard M. Vogel
2016, Water Resources Research (52) 5619-5633
Environmental simulation models, such as precipitation-runoff watershed models, are increasingly used in a deterministic manner for environmental and water resources design, planning, and management. In operational hydrology, simulated responses are now routinely used to plan, design, and manage a very wide class of water resource systems. However, all such models...
Managing water and riparian habitats on the Bill Williams River with scientific benefit for other desert river systems
John Hickey, Woodrow Fields, Andrew Hautzinger, Steven Sesnie, Patrick B. Shafroth, Dick Gilbert
2016, Report
This report details modeling to: 1) codify flow-ecology relationships for riparian species of the Bill Williams River as operational guidance for water managers, 2) test the guidance under different climate scenarios, and 3) revise the operational guidance as needed to address the effects of climate change. Model applications detailed herein...
Hydrogeologic investigations of the Miocene Nogales Formation in the Nogales Area, Upper Santa Cruz Basin, Arizona
William R. Page, Floyd Gray, Mark W. Bultman, Christopher M. Menges
2016, Scientific Investigations Report 2016-5087
Hydrogeologic investigations were conducted to evaluate the groundwater resource potential for the Miocene Nogales Formation in the Nogales area, southern Arizona. Results indicate that parts of the formation may provide new, deeper sources of groundwater for the area. Geologic mapping determined the hydrogeologic framework of the formation by defining lithologic,...
ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars
Sylvestre Maurice, Samuel M. Clegg, Roger C. Wiens, O. Gasnault, W. Rapin, O. Forni, Agnes Cousin, V. Sautter, Nicolas Mangold, L. Le Deit, Marion Nachon, Ryan B. Anderson, Nina Lanza, Cecile Fabre, Valerie Payre, Jeremie Lasue, Pierre-Yves Meslin, Richard A. LeVeille, Bruce Barraclough, Pierre Beck, Steven C. Bender, Gilles Berger, John C. Bridges, Nathan Bridges, Gilles Dromert, M. Darby Dyar, Raymond Francis, Jens Frydenvang, B. Gondet, Bethany L. Ehlmann, Kenneth E. Herkenhoff, Jeffrey R. Johnson, Yves Langevin, Madsen Morten B., N. Melikechi, J.-L. Lacour, Stephane Le Mouelic, Eric Lewin, Horton E. Newsom, Ann M. Ollila, Patrick Pinet, S. Schroder, Jean-Baptiste Sirven, Robert L. Tokar, M.J. Toplis, Claude d’Uston, David Vaniman, Ashwin R. Vasavada
2016, Journal of Analytical Atomic Spectrometry (31) 863-889
At Gale crater, Mars, ChemCam acquired its first laser-induced breakdown spectroscopy (LIBS) target on Sol 13 of the landed portion of the mission (a Sol is a Mars day). Up to Sol 800, more than 188 000 LIBS spectra were acquired on more than 5800 points distributed over about 650 individual...
Ordinary kriging as a tool to estimate historical daily streamflow records
William H. Farmer
2016, Hydrology and Earth System Sciences (20) 2721-2735
Efficient and responsible management of water resources relies on accurate streamflow records. However, many watersheds are ungaged, limiting the ability to assess and understand local hydrology. Several tools have been developed to alleviate this data scarcity, but few provide continuous daily streamflow records at individual streamgages within an entire region....
Regional flow duration curves: Geostatistical techniques versus multivariate regression
Alessio Pugliese, William H. Farmer, Attilio Castellarin, Stacey A. Archfield, Richard M. Vogel
2016, Advances in Water Resources (96) 11-22
A period-of-record flow duration curve (FDC) represents the relationship between the magnitude and frequency of daily streamflows. Prediction of FDCs is of great importance for locations characterized by sparse or missing streamflow observations. We present a detailed comparison of two methods which are capable of predicting an FDC at ungauged...
Granitic boulder erosion caused by chaparral wildfire: Implications for cosmogenic radionuclide dating of bedrock surfaces
Katherine J. Kendrick, Camille Partin, Robert C. Graham
2016, Journal of Geology (124)
Rock surface erosion by wildfire is significant and widespread but has not been quantified in southern California or for chaparral ecosystems. Quantifying the surface erosion of bedrock outcrops and boulders is critical for determination of age using cosmogenic radionuclide techniques, as even modest surface erosion removes the accumulation of the...
Influence of climate drivers on colonization and extinction dynamics of wetland-dependent species
Andrew M. Ray, William R. Gould, Blake R. Hossack, Adam J. Sepulveda, David P. Thoma, Debra A. Patla, Rob Daley, Robert K. Al-Chokhachy
2016, Ecosphere (7)
Freshwater wetlands are particularly vulnerable to climate change. Specifically, changes in temperature, precipitation, and evapotranspiration (i.e., climate drivers) are likely to alter flooding regimes of wetlands and affect the vital rates, abundance, and distributions of wetland-dependent species. Amphibians may be among the most climate-sensitive wetland-dependent groups, as many species rely...
The missing large impact craters on Ceres
S. Marchi, A. Ermakov, C.A. Raymond, R.R. Fu, D.P. O’Brien, Michael T. Bland, E. Ammannito, De Sanctis, Tim Bowling, P. Schenk, J.E.C. Scully, D.L. Buczkowski, D.A. Williams, H. Hiesinger, C.T. Russell
2016, Nature Communications (7) Article #12257
Asteroids provide fundamental clues to the formation and evolution of planetesimals. Collisional models based on the depletion of the primordial main belt of asteroids predict 10–15 craters >400 km should have formed on Ceres, the largest object between Mars and Jupiter, over the last 4.55 Gyr. Likewise, an...
Identifying key climate and environmental factors affecting rates of post-fire big sagebrush (Artemisia tridentata) recovery in the northern Columbia Basin, USA
Douglas J. Shinneman, Susan K. McIlroy
2016, International Journal of Wildland Fire (25) 933-945
Sagebrush steppe of North America is considered highly imperilled, in part owing to increased fire frequency. Sagebrush ecosystems support numerous species, and it is important to understand those factors that affect rates of post-fire sagebrush recovery. We explored recovery of Wyoming big sagebrush (Artemisia tridentata ssp.wyomingensis) and basin big sagebrush (A....
Effects of diffusion on total biomass in heterogeneous continuous and discrete-patch systems
Donald L. DeAngelis, Wei Ming Ni, Bo Zhang
2016, Theoretical Ecology (9) 443-453
Theoretical models of populations on a system of two connected patches previously have shown that when the two patches differ in maximum growth rate and carrying capacity, and in the limit of high diffusion, conditions exist for which the total population size at equilibrium exceeds that of the ideal free...
Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California
Mark E. Hereford
2016, Open-File Report 2016-1112
The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land...
Subsidence rates at the southern Salton Sea consistent with reservoir depletion
Andrew J. Barbour, Eileen Evans, Stephen H. Hickman, Mariana Eneva
2016, Journal of Geophysical Research B: Solid Earth (121) 5308-5327
Space geodetic measurements from the Envisat satellite between 2003 and 2010 show that subsidence rates near the southeastern shoreline of the Salton Sea in Southern California are up to 52mmyr−1 greater than the far-field background rate. By comparing these measurements with model predictions, we find that this subsidence appears to...
Cheatgrass percent cover change: Comparing recent estimates to climate change − Driven predictions in the Northern Great Basin
Stephen P. Boyte, Bruce K. Wylie, Donald J. Major
2016, Rangeland Ecology and Management (69) 265-279
Cheatgrass (Bromus tectorum L.) is a highly invasive species in the Northern Great Basin that helps decrease fire return intervals. Fire fragments the shrub steppe and reduces its capacity to provide forage for livestock and wildlife and habitat critical to sagebrush obligates. Of particular interest is the greater sage grouse (Centrocercus...
Variability of bed drag on cohesive beds under wave action
Ilgar Safak
2016, Water (8)
Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations...
