Publications
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Monitoring gas and heat emissions at Norris Geyser Basin, Yellowstone National Park, USA based on a combined eddy covariance and Multi-GAS approach
We quantified gas and heat emissions in an acid-sulfate, vapor-dominated area (0.04-km2) of Norris Geyser Basin, located just north of the 0.63 Ma Yellowstone Caldera and near an area of anomalous uplift. From 14 May to 3 October 2016, an eddy covariance system measured half-hourly CO2, H2O and sensible (H) and latent (LE) heat fluxes and a Multi-GAS instrument measured (1 Hz frequency)...
Authors
Jennifer L. Lewicki, Peter J. Kelly, Deborah Bergfeld, R. Greg Vaughan, Jacob B. Lowenstern
Origin of discrepancies between crater size-frequency distributions of coeval lunar geologic units via target property contrasts
Recent work on dating Copernican-aged craters, using Lunar Reconnaissance Orbiter (LRO) Camera data, re-encountered a curious discrepancy in crater size-frequency distribution (CSFD) measurements that was observed, but not understood, during the Apollo era. For example, at Tycho, Copernicus, and Aristarchus craters, CSFDs of impact melt deposits give significantly younger relative and...
Authors
Carolyn H. Van der Bogert, Harald Hiesinger, Colin M. Dundas, T. Kruger, Alfred S. McEwen, Michael Zanetti, Mark S. Robinson
The effects of snow and salt on ice table stability in University Valley, Antarctica
The Antarctic Dry Valleys represent a unique environment where it is possible to study dry permafrost overlaying an ice-rich permafrost. In this paper, two opposing mechanisms for ice table stability in University Valley are addressed: i) diffusive recharge via thin seasonal snow deposits and ii) desiccation via salt deposits in the upper soil column. A high-resolution time-marching soil...
Authors
Kaj E. Williams, Jennifer L. Heldmann, Christopher P. McKay, Michael T. Mellon
Martian cave air-movement via Helmholtz resonance
Infrasonic resonance has previously been measured in terrestrial caves by other researchers, where Helmholtz resonance has been suggested as the plausible mechanism resulting in periodic wind reversals within cave entrances. We extend this reasoning to possible Martian caves, where we examine the characteristics of four atypical pit craters (APCs) on Tharsis, suggested as candidate cave...
Authors
Kaj E. Williams, Timothy N. Titus, Chris Okubo, Glen E. Cushing
The interior structure of Ceres as revealed by surface topography
Ceres, the largest body in the asteroid belt (940 km diameter), provides a unique opportunity to study the interior structure of a volatile-rich dwarf planet. Variations in a planetary body's subsurface rheology and density affect the rate of topographic relaxation. Preferential attenuation of long wavelength topography (≥150 km) on Ceres suggests that the viscosity of its crust...
Authors
Roger R. Fu, Anton Ermakov, Simone Marchi, Julie C. Castillo-Rogez, Carol A. Raymond, Bradford Hager, Maria Zuber, Scott King, Michael T. Bland, Maria Cristina De Sanctis, Frank Preusker, Ryan S. Park, Christopher T. Russell
Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution
Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials...
Authors
H.G. Sizemore, Thomas Platz, Norbert Schorghofer, Thomas H. Prettyman, Maria Cristina De Sanctis, David A. Crown, Nico Schmedemann, Andeas Nessemann, Thomas Kneissl, Simone Marchi, Paul M. Schenk, Michael T. Bland, B.E. Schmidt, Kynan H.G. Hughson, F. Tosi, F. Zambon, Scott C. Mest, R.A. Yingst, D.A. Williams, C.T. Russell, C.A. Raymond
Selection of the InSight landing site
The selection of the Discovery Program InSight landing site took over four years from initial identification of possible areas that met engineering constraints, to downselection via targeted data from orbiters (especially Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE) images), to selection and certification via sophisticated...
Authors
M. P. Golombek, D. Kipp, N. R. Warner, Ingrid J. Daubar, Robin L. Fergason, Randolph L. Kirk, R. A. Beyer, A. Huertas, Sylvain Piqueux, N.E. Putzig, B.A. Campbell, G. A. Morgan, C. Charalambous, W. T. Pike, Klaus Gwinner, F. Calef, D. Kass, M. A. Mischna, J. Ashley, C. Bloom, N. Wigton, T. Hare, C. C. Schwartz, H. Gengl, L. Redmond, M. Trautman, J. Sweeney, C. Grima, I. B. Smith, E. Sklyanskiy, M. Lisano, J. Benardini, Suzanne E. Smrekar, Philippe Lognonné, W. B. Banerdt
Viscous relaxation of Ganymede's impact craters: Constraints on heat flux
Measurement of crater depths in Ganymede’s dark terrain have revealed substantial numbers of unusually shallow craters indicative of viscous relaxation [see companion paper: Singer, K.N., Schenk, P. M., Bland, M.T., McKinnon, W.B., (2017). Relaxed impact craters on Ganymede: Regional variations and high heat flow. Icarus, submitted]. These viscously relaxed craters provide insight into...
Authors
Michael T. Bland, Kelsi N. Singer, William B. McKinnon, Paul M. Schenk
The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in-flight calibration, validation, and data archiving
The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted ~2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20° × 15° over the...
Authors
James F. Bell, A. Godber, S. McNair, M.A. Caplinger, J.N. Maki, M. T. Lemmon, J. L. van Beek, M.C. Malin, D. Wellington, K.M. Kinch, M.B. Madsen, Craig J. Hardgrove, M.A. Ravine, E. Gray Jensen, D. Harker, Ryan Anderson, Kenneth E. Herkenhoff, R.V. Morris, E. Cisneros, R.G. Deen
In situ detection of boron by ChemCam on Mars
We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels
Authors
Patrick J. Gasda, Ethan B. Haldeman, Roger C. Wiens, William Rapin, Thomas F. Bristow, John W. Bridges, Susanne P. Schwenzer, Benton Clark, Kenneth E. Herkenhoff, Jens Frydenvang, Nina L. Lanza, Sylvestre Maurice, Samuel M. Clegg, Dorothea M. Delapp, Veronica L. Sanford, Madeleine R. Bodine, Rhonda E. McInroy
The planetary data system
In the early 1980s, the Space Science Board (SSB) of the National Research Council was concerned about the poor and inconsistent treatment of scientific information returned from NASA’s space science missions. The SSB formed a panel [The Committee on Data Management and Computation (CODMAC)] to assess the situation and make recommendations to NASA for improvements. The CODMAC panel...
Authors
Charles H. Acton, Susan Slavney, Raymond E. Arvidson, Lisa Gaddis, Mitchell K. Gordon, Susan Lavoie
An evaluation of sampling and full enumeration strategies for Fisher Jenks classification in big data settings
Large data contexts present a number of challenges to optimal choropleth map classifiers. Application of optimal classifiers to a sample of the attribute space is one proposed solution. The properties of alternative sampling-based classification methods are examined through a series of Monte Carlo simulations. The impacts of spatial autocorrelation, number of desired classes, and form of...
Authors
Sergio J. Rey, Philip A. Stephens, Jason R. Laura