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Boise State University

Selected Works

2011

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Absolute Quantification Of Gene Expression In Individual Bacterial Cells Using Two-Photon Fluctuation Microscopy, Matthew L. Ferguson, Dominique Le Coq, Matthieu Jules, Stéphane Aymerich, Nathalie Declerck, Catherine A. Royer Dec 2011

Absolute Quantification Of Gene Expression In Individual Bacterial Cells Using Two-Photon Fluctuation Microscopy, Matthew L. Ferguson, Dominique Le Coq, Matthieu Jules, Stéphane Aymerich, Nathalie Declerck, Catherine A. Royer

Matthew L. Ferguson

Quantification of promoter activity or protein expression in gene regulatory networks is generally achieved via measurement of fluorescent protein (FP) intensity, which is related to the true FP concentration by an unknown scaling factor, thereby limiting analysis and interpretation. Here, using approaches originally developed for eukaryotic cells, we show that two-photon (2p) fluorescence fluctuation microscopy, specifically scanning number and brightness (sN&B) analysis, can be applied to determine the absolute concentrations of diffusing FPs in live bacterial cells. First, we demonstrate the validity of the approach, despite the small size of the bacteria, using the central pixels and spatial averaging. We …


Cardinal Invariants And The Borel Tukey Order, Samuel Coskey Dec 2011

Cardinal Invariants And The Borel Tukey Order, Samuel Coskey

Samuel Coskey

Many proofs of inequalities between cardinal characteristics of the continuum are combinatorial in nature. These arguments can be carried out in any model of set theory, even a model of CH where the inequalities themselves are trivial. Thus, such arguments appear to establish a stronger relationship than a mere inequality. The Borel Tukey order was introduced by Blass in a 1996 article to address just this. Specifically, he observed that the combinatorial information linking two cardinal characteristics is often captured by a pair of Borel maps called a Borel Tukey morphism. The existence of a Borel Tukey morphisms between …


The Impact Of ‘‘No Impact Man’’: Alternative Hedonism As Environmental Appeal, Jen Schneider, Glen Miller Dec 2011

The Impact Of ‘‘No Impact Man’’: Alternative Hedonism As Environmental Appeal, Jen Schneider, Glen Miller

Jen Schneider

As ‘‘No Impact Man,’’ writer Colin Beavan conducted a one-year experiment to determine whether he and his family could reduce their environmental impact to zero while living and working in Manhattan. This article examines the No Impact Man (NIM) experiment both as ‘‘alternative hedonism,’’ a reconceptualization of the ‘‘good life’’ that avoids unduly damaging the natural world, and also as a kind of ‘‘eco-stunt,’’ an attempt to garner significant media coverage about positive environmental behaviors. We use DeLuca’s theorization of the ‘‘image event’’ to analyze the No Impact Man franchise—blog, book, and documentary film—though we modify that theory in order …


Meteorological Conditions At Racetrack Playa, Death Valley National Park: Implications For Rock Production And Transport, Ralph D. Lorenz, Brian K. Jackson, Jason W. Barnes, Joseph N. Spitale, Jani Radebaugh, Kevin H. Baines Dec 2011

Meteorological Conditions At Racetrack Playa, Death Valley National Park: Implications For Rock Production And Transport, Ralph D. Lorenz, Brian K. Jackson, Jason W. Barnes, Joseph N. Spitale, Jani Radebaugh, Kevin H. Baines

Brian Jackson

Three decades of weather records at meteorological stations near Death Valley National Park are analyzed in an attempt to gauge the frequency of conditions that might form and erase the famous trails of wind-blown rocks in the mud of Racetrack Playa. Trail formation requires the playa to be wet, followed by strong winds and/or freezing conditions. Weather records are compared with a limited set of meteorological data that were acquired in situ at the playa over three winters and that indicate freezing on 50, 29, and 15 nights during the winters of 2007/08–09/10, respectively, as well as with the hydrological …


Multiscale/Multiphysics Modeling Of Concrete Structures, Yang Lu Dec 2011

Multiscale/Multiphysics Modeling Of Concrete Structures, Yang Lu

Yang Lu

Concrete structure modeling is not easy. Cement concrete has a complex microstructure, which is still not completely elucidated. A lot of study has been carried out in cement concrete materials and structures modeling. The microstructure of concrete contains random features over a wide range of length scales, from nanometers to millimeters, with each length scale presenting a random composite. In its engineering uses, concrete is considered as a uniform material at the length scale of meters. Concrete research topics include complex failure processes, such as, atomic scale cementitious hydration, micro-pore structure formation and moisture transport in microstructure, calcium ion transport …


Ereading For Research, Michelle Armstrong Nov 2011

Ereading For Research, Michelle Armstrong

Michelle Armstrong

Data on ebooks is beginning to show that this format is transforming the library world. More and more libraries are developing ebook collections and patrons are learning to expect this format as an option. Much of this success is the result of devices like the Kindle and iPad which mimic a much more natural reading experience, at least in the traditional sense. Reading a novel or any text straight through works well on these devices. However, not every type of reader interacts with a book like this and in fact many academic faculty and researchers need more freedom to read …


Integration Of Climate Change In The Analysis And Design Of Engineered Systems: Barriers And Opportunities For Engineering Education, Juan Lucena, Jason Delborne, Katie Johnson, Jon Leydens, Junko Munakata-Marr, Jen Schneider Nov 2011

Integration Of Climate Change In The Analysis And Design Of Engineered Systems: Barriers And Opportunities For Engineering Education, Juan Lucena, Jason Delborne, Katie Johnson, Jon Leydens, Junko Munakata-Marr, Jen Schneider

Jen Schneider

The goal of this paper is to begin mapping perspectives of engineering faculty on barriers and opportunities related to the integration of climate change in the analysis and design of engineered systems (CC&ES). Although both sustainability and renewable energy have been receiving increasing attention in engineering education for quite some time1, climate change, especially as it relates to engineered systems, has yet to become a widely accepted topic of teaching and research. From recent literature on engineering education and from interviews with engineering faculty, a picture emerges of whether and how climate change is an important dimension in …


On The Interaction Of Variation And Exceptionality In Modern Hebrew Spirantization, Michal Martinez Oct 2011

On The Interaction Of Variation And Exceptionality In Modern Hebrew Spirantization, Michal Martinez

Michal Temkin Martinez

Modern Hebrew (MH) spirantization is a variable phenomenon with many exceptions. Adam (2002) claims that the variation is driven by the exceptions and concludes that spirantization is changing, yielding what is currently a variable grammar, with expected and variant forms in free variation, and moving toward one with no alternation. This paper reports the results of an acceptability rating task showing that, in alternating segments, the expected form is still rated as more acceptable than that variant forms, and that which variant surfaces (stop or fricative) depend on its underlying root position. Additionally, participants indicate that some variation is acceptable …


Kepler And Ground-Based Transits Of The Exo-Neptune Hat-P-11b, Drake Deming, Pedro V. Sada, Brian Jackson, Steven W. Peterson, Eric Agol, Heather A. Knutson, Donald E. Jennings, Flynn Haase, Kevin Bays Oct 2011

Kepler And Ground-Based Transits Of The Exo-Neptune Hat-P-11b, Drake Deming, Pedro V. Sada, Brian Jackson, Steven W. Peterson, Eric Agol, Heather A. Knutson, Donald E. Jennings, Flynn Haase, Kevin Bays

Brian Jackson

We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields Rp = 4.31 R⊕ ± 0.06 R ⊕ and Rs = 0.683 R☉ ± 0.009 R☉, both about 3σ smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening …


Qr Codes: A Guide For Libraries, Memo Cordova Oct 2011

Qr Codes: A Guide For Libraries, Memo Cordova

Jose Guillermo "Memo" Cordova Silva

No abstract provided.


Self-Assembly On (111)-Oriented Iii-V Surfaces, Paul J. Simmonds, Minjoo Larry Lee Sep 2011

Self-Assembly On (111)-Oriented Iii-V Surfaces, Paul J. Simmonds, Minjoo Larry Lee

Paul J. Simmonds

We demonstrate the self-assembly of tensile strained GaP into three-dimensional dots on GaAs(111)A. Size and areal density of the dislocation-free GaPdots are readily tunable with both substrate temperature and deposition thickness. GaP dot growth obeys island scaling theory, allowing us to predict dot size distributions a priori.


Molecular Beam Epitaxy Approach To The Graphitization Of Gaas(100) Surfaces, Paul J. Simmonds, John Simon, Jerry M. Woodall, Minjoo Larry Lee May 2011

Molecular Beam Epitaxy Approach To The Graphitization Of Gaas(100) Surfaces, Paul J. Simmonds, John Simon, Jerry M. Woodall, Minjoo Larry Lee

Paul J. Simmonds

The authors present a method for obtaining graphitized carbon on GaAs(100) surfaces. Carbon-doped GaAs is grown by molecular beam epitaxy before controlled thermal etching within the growth chamber. An AlAs layer beneath the carbon-doped GaAs acts as a thermal etch stop. As the GaAs is etched away, the carbondopant atoms remain on the surface due to their low vapor pressure. The total number of carbon atoms available is precisely controllable by the doping density and thickness of the carbon-doped GaAs layer. Characteristic phonon modes in Raman spectra from the thermally etchedsurfaces show that the residual surfacecarbon atoms form sp2 …


Molecular Beam Epitaxy Of Metamorphic InYGa1−YP Solar Cells On Mixed Anion GaasXP1−X/Gaas Graded Buffers, Stephanie Tomasulo, John Simon, Paul J. Simmonds, Jonathan Biagiotti, Minjoo L. Lee May 2011

Molecular Beam Epitaxy Of Metamorphic InYGa1−YP Solar Cells On Mixed Anion GaasXP1−X/Gaas Graded Buffers, Stephanie Tomasulo, John Simon, Paul J. Simmonds, Jonathan Biagiotti, Minjoo L. Lee

Paul J. Simmonds

The authors have grown metamorphic InyGa1−yP on optimized GaAsxP1−x/GaAs graded buffers via solid source molecular beam epitaxy(MBE) for multijunction solar cell applications. In this work, the authors show that a previously developed kinetic growth model can be used to predict the composition of mixed anion GaAsxP1−x alloys on GaAs as a function of substrate temperature and group-V flux. The advantages of using a high growth temperature of 700 °C are then described, including the minimized dependence of composition on small temperature variations, a linear dependence of film composition on …


No Fees Required: Opening Access To University Content (Tech Talk), Michelle Armstrong, Julia Stringfellow May 2011

No Fees Required: Opening Access To University Content (Tech Talk), Michelle Armstrong, Julia Stringfellow

Michelle Armstrong

This article shares information from a presentation at the 2011 Southwest Idaho Library Association Regional Conference, which explored increased access to university collections and scholarship and the great benefits this provides for all library communities. Access to university records and scholarship, both born digital and originally in paper, is improved by providing them in an open, electronic format. The session featured examples of institutional repositories and the types of digital content they include, and provided resources with information on creating and implementing an institutional repository.


A Comparison Of Two Open Source Lidar Surface Classification Algorithms, Wade T. Tinkham, Hongyu Huang, Alistair M.S. Smith, Rupesh Shrestha, Michael J. Falkowski, Andrew T. Hudak, Timothy E. Link, Nancy F. Glenn, Danny G. Marks Mar 2011

A Comparison Of Two Open Source Lidar Surface Classification Algorithms, Wade T. Tinkham, Hongyu Huang, Alistair M.S. Smith, Rupesh Shrestha, Michael J. Falkowski, Andrew T. Hudak, Timothy E. Link, Nancy F. Glenn, Danny G. Marks

Nancy Glenn

With the progression of LiDAR (Light Detection and Ranging) towards a mainstream resource management tool, it has become necessary to understand how best to process and analyze the data. While most ground surface identification algorithms remain proprietary and have high purchase costs; a few are openly available, free to use, and are supported by published results. Two of the latter are the multiscale curvature classification and the Boise Center Aerospace Laboratory LiDAR (BCAL) algorithms. This study investigated the accuracy of these two algorithms (and a combination of the two) to create a digital terrain model from a raw LiDAR point …


Structured Multiple Endosymbiosis Of Bacteria And Archaea In A Ciliate From Marine Sulfidic Sediments: A Survival Mechanism In Low Oxygen, Sulfidic Sediments?, Virginia P. Edgcomb, Edward R. Leadbetter, William A. Bourland, David Beaudoin, Joan M. Bernhard Mar 2011

Structured Multiple Endosymbiosis Of Bacteria And Archaea In A Ciliate From Marine Sulfidic Sediments: A Survival Mechanism In Low Oxygen, Sulfidic Sediments?, Virginia P. Edgcomb, Edward R. Leadbetter, William A. Bourland, David Beaudoin, Joan M. Bernhard

William Bourland

Marine micro-oxic to sulfidic environments are sites of intensive biogeochemical cycling and elemental sequestration, where prokaryotes are major driving forces mediating carbon, nitrogen, sulfur, phosphorus, and metal cycles, important from both biogeochemical and evolutionary perspectives. Associations between single-celled eukaryotes and bacteria and/or archaea are common in such habitats. Here we describe a ciliate common in the micro-oxic to anoxic, typically sulfidic, sediments of Santa Barbara Basin (CA, USA). The ciliate is 95% similar to Parduzcia orbis (18S rRNA). Transmission electron micrographs reveal clusters of at least three different endobiont types organized within membrane-bound sub-cellular regions. Catalyzed reporter deposition–fluorescent in situ …


Making The Human Dimensions Of Sustainable Community Development Visible To Engineers, Juan Lucena, Jen Schneider, Jon A. Leydens Mar 2011

Making The Human Dimensions Of Sustainable Community Development Visible To Engineers, Juan Lucena, Jen Schneider, Jon A. Leydens

Jen Schneider

Recently, engineers – particularly those working on sustainability-related initiatives – have increasingly turned their efforts towards under-served communities. This paper summarises the findings in Engineering and Sustainable Community Development (Juan Lucena et al., 2010) aimed at a diversity of these efforts which are grouped here under the term ‘engineering to help’. These initiatives often exist under names such as community service, humanitarian engineering, and engineers without borders or activities such as the Institution of Civil Engineers' co-sponsored workshop ‘Helping local communities to help themselves’. Although there has been a blossoming of engineering-to-help-related programmes around the world, there is a …


How Do Mathematicians Make Sense Of Definitions?, Laurie O. Cavey, Margaret T. Kinzel, Thomas A. Kinzel, Kathleen L. Rohrig, Sharon B. Walen Feb 2011

How Do Mathematicians Make Sense Of Definitions?, Laurie O. Cavey, Margaret T. Kinzel, Thomas A. Kinzel, Kathleen L. Rohrig, Sharon B. Walen

Laurie O. Cavey

It seems clear that students’ activity while working with definitions differs from that of mathematicians. The constructs of concept definition and concept image have served to support analyses of both mathematicians’ and students’ work with definitions (c.f. Edwards & Ward, 2004; Tall & Vinner, 1981). As part of an ongoing study, we chose to look closely at how mathematicians make sense of definitions in hopes of informing the ways in which we interpret students’ activity and support their understanding of definitions. We conducted interviews with mathematicians in an attempt to reveal their process when making sense of definitions. A striking …


Beyond Foursquare: Library Treks With Scvngr, Amy E. Vecchione, Margaret Mellinger Feb 2011

Beyond Foursquare: Library Treks With Scvngr, Amy E. Vecchione, Margaret Mellinger

Amy E. Vecchione

SCVNGR is a game-based geolocation application where users can earn points or gain rewards by completing challenges and treks. Builders design questions that involve text based answers (open ended or multiple choice), QR codes, or photo challenges. Librarians at Boise State University and Oregon State University have built treks and challenges using SCVNGR for library orientations and instruction. They have found SCVNGR a better environment than Foursquare for these purposes. With SCVNGR, students can participate in the challenges and treks using not only their smart phones and mobile devices, but also via text-messaging and laptops. Librarians can easily create multiple …


Reference Is Neither Here Nor There: Connecting Through Sms, Amy E. Vecchione, Margie Ruppel Feb 2011

Reference Is Neither Here Nor There: Connecting Through Sms, Amy E. Vecchione, Margie Ruppel

Amy E. Vecchione

Have you ever wondered what your patrons think about SMS reference service? Do you wonder what other libraries are doing with SMS? Or what types of questions you would be asked through SMS reference service? Don’t try to reinvent the wheel! Join Boise State University librarians Amy Vecchione and Margie Ruppel to learn the results from their recently conducted national and local surveys on SMS reference. By attending this session participants will learn the most common types of questions asked through SMS, ways to market this service, best practices for answering SMS reference questions, and patrons’ perceptions of this new …


Graphitized Carbon On Gaas(100) Substrates, J. Simon, P. J. Simmonds, J. M. Woodall, M. L. Lee Feb 2011

Graphitized Carbon On Gaas(100) Substrates, J. Simon, P. J. Simmonds, J. M. Woodall, M. L. Lee

Paul J. Simmonds

We report on the formation of graphitized carbon on GaAs(100) surfaces by molecular beam epitaxy. We grew highly carbon-doped GaAs on AlAs, which was then thermally etched in situ leaving behind carbon atoms on the surface. After thermal etching, Raman spectra revealed characteristic phonon modes for sp2-bonded carbon, consistent with the formation of graphitic crystallites. We estimate that the graphitic crystallites are 1.5–3 nm in size and demonstrate that crystallite domain size can be increased through the use of higher etch temperatures.


Canal Structure Automation Rules Using An Accuracy-Based Learning Classifier System, A Genetic Algorithm, And A Hydraulic Simulation Model. I: Design, J. E. Hernandez, G. P. Merkley Jan 2011

Canal Structure Automation Rules Using An Accuracy-Based Learning Classifier System, A Genetic Algorithm, And A Hydraulic Simulation Model. I: Design, J. E. Hernandez, G. P. Merkley

Jairo E. Hernández

Using state-of-the-art computational techniques, a genetic algorithm (GA) and an accuracy-based learning classifier system (XCS) were shown to produce optimal operational solutions for gate structures in irrigation canals. An XCS successfully developed a set of operational rules for canal gates through the exploration and exploitation of rules using a GA, with the support of an unsteady-state hydraulic simulation model. A computer program which implemented the XCS was used to develop operational rules to operate all canal gate structures simultaneously, while maintaining water depth near target values during variable-demand periods, and with a hydraulically stabilized system when demands no longer changed. …


A Meta-Analysis Of Global Urban Land Expansion, Karen C. Seto, Michail Fragkias, Burak Güneralp, Michael K. Reilly Jan 2011

A Meta-Analysis Of Global Urban Land Expansion, Karen C. Seto, Michail Fragkias, Burak Güneralp, Michael K. Reilly

Michail Fragkias

The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land area of 58,000 km2 from 1970 to 2000. India, China, and Africa have experienced the highest rates of urban land expansion, and the largest change in total urban extent has occurred in North America. Across all regions …


Getting Social In A Small Academic Library, Elizabeth Ramsey Jan 2011

Getting Social In A Small Academic Library, Elizabeth Ramsey

Elizabeth Ramsey

Libraries of all shapes and sizes are being exhorted to take advantage of the outreach and promotion opportunities available to them for free through the use of social networking. However, to avoid the pitfalls of an unfocused or unsuccessful program most experts agree that you’ll need to first consider: why you want to use social networking, where in the wide, wide web you want to start building your community, who will be responsible for the content, what that content will be, and how the effectiveness of your social media efforts will be measured. This article will examine strategies advocated by …


Metamorphic Gaasp Buffers For Growth Of Wide-Bandgap Ingap Solar Cells, J. Simon, S. Tomasulo, P. J. Simmonds, M. Romero, M. L. Lee Jan 2011

Metamorphic Gaasp Buffers For Growth Of Wide-Bandgap Ingap Solar Cells, J. Simon, S. Tomasulo, P. J. Simmonds, M. Romero, M. L. Lee

Paul J. Simmonds

GaAsxP1−x graded buffers were grown via solid source molecular beam epitaxy(MBE) to enable the fabrication of wide-bandgap InyGa1−yP solar cells. Tensile-strained GaAsxP1−x buffers grown on GaAs using unoptimized conditions exhibited asymmetric strain relaxation along with formation of faceted trenches, 100–300 nm deep, running parallel to the [011] direction. We engineered a 6 μm thick grading structure to minimize the faceted trench density and achieve symmetric strain relaxation while maintaining a threading dislocation density of ≤106 cm−2. In comparison, compressively-strained graded GaAsxP1−x buffers on …


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 Jan 2011

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

Nancy Glenn

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 in southern Idaho, USA. We also examined how temporal trends in nutrient fluxes were affected by changes in particle sizes of eroded mass as well as nutrient concentrations associated with different particle size classes. In the burned area, total carbon (C) and nitrogen (N) fluxes were as high as 235 …


Optimal And Approximate Methods For Detection Of Uncoded Data With Carrier Phase Noise, Rajet Krishnan, Hani Mehrpouyan, Thomas Eriksson, Tommy Svensson Jan 2011

Optimal And Approximate Methods For Detection Of Uncoded Data With Carrier Phase Noise, Rajet Krishnan, Hani Mehrpouyan, Thomas Eriksson, Tommy Svensson

Hani Mehrpouyan

Previous results in the literature have shown that derivation of the optimum maximum-likelihood (ML) receiver for symbol-by-symbol (SBS) detection of an uncoded data sequence in the presence of random phase noise is an intractable problem, since it involves the computation of the conditional probability distribution function (PDF) of the phase noise process. In this paper, we seek to minimize symbol error probability (SEP), which is achieved by SBS detection of the sequence based on all received signals. We show that the ML detector for this problem can be formulated as a weighted sum of central moments of the conditional PDF …


Moving Forward With Citizen Deliberation: Lessons And Inspiration From The National Citizens' Technology Forum, Jason Delborne, Jen Schneider Jan 2011

Moving Forward With Citizen Deliberation: Lessons And Inspiration From The National Citizens' Technology Forum, Jason Delborne, Jen Schneider

Jen Schneider

In his article on the National Citizens' Technology Forum (NCTF) in this chapter, Cobb notes that the NCTF was essentially a decendant of the "consensus conference," a form of political engagement that originated in Denmark and then traveled elsewhere. Sponsored by the Danish Parliament, the Danish Board of Technology was tasked with involving groups of citizens in making informed policy recommendations related to science and technology: these policy recommendations were and are considered by lawmakers in forming science policy. Cobb and others have noted that the consensus conference and related forms of public engagement have garnered significant academic interest in …


Putting Partnership First: A Dialogue Model For Science And Risk Communication, Jen Schneider, Roel Snieder Jan 2011

Putting Partnership First: A Dialogue Model For Science And Risk Communication, Jen Schneider, Roel Snieder

Jen Schneider

In April 2010, the New York Times reported that Vattenfall AB, an energy company owned by the Swedish government, had built one of the first coal-fired power plants designed to capture ~90% of the CO2 it produced, with plans to sequester that CO2 underground in geologic repositories near its plant in Brandenburg, Germany (Voosen, 2010). By most measures, if the plant's operations were proven to be successful, it could have served as a model for other carbon capture and sequestration plants worldwide.


Ice Rafts Not Sails: Floating The Rocks At Racetrack Playa, Ralph D. Lorenz, Brian K. Jackson, Jason W. Barnes, Joe Spitale, John M. Keller Jan 2011

Ice Rafts Not Sails: Floating The Rocks At Racetrack Playa, Ralph D. Lorenz, Brian K. Jackson, Jason W. Barnes, Joe Spitale, John M. Keller

Brian Jackson

We suggest that the existence of many of the rock-carved trails at Racetrack Playa in Death Valley National Park is predominantly due to the effect of arbitrarily weak winds on rocks that are floated off the soft bed by small rafts of ice, as also occurs in arctic tidal beaches to form boulder barricades. These ice cakes need not have a particularly large surface area if the ice is adequately thick—the ice cakes allow the rocks to move by buoyantly reducing the reaction and friction forces at the bed, not by increasing the wind drag. The parameter space of ice …