Publications
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Latitudinal variations in Titan's methane and haze from Cassini VIMS observations
We analyze observations taken with Cassini's Visual and Infrared Mapping Spectrometer (VIMS), to determine the current methane and haze latitudinal distribution between 60??S and 40??N. The methane variation was measured primarily from its absorption band at 0.61 ??m, which is optically thin enough to be sensitive to the methane abundance at 20-50 km altitude. Haze characteristics were...
Authors
P.F. Penteado, C.A. Griffith, M.G. Tomasko, S. Engel, C. See, Lyn R. Doose, K. H. Baines, R. H. Brown, Bonnie J. Buratti, R. N. Clark, P. D. Nicholson, Christophe Sotin
Dione's spectral and geological properties
We present a detailed analysis of the variations in spectral properties across the surface of Saturn's satellite Dione using Cassini/VIMS data and their relationships to geological and/or morphological characteristics as seen in the Cassini/ISS images. This analysis focuses on a local region on Dione's anti-saturnian hemisphere that was observed by VIMS with high spatial resolution...
Authors
K. Stephan, R. Jaumann, R. Wayne Wagner, R. N. Clark, D. P. Cruikshank, C. A. Hibbitts, T. Roatsch, H. Hoffmann, R. H. Brown, G. Filiacchione, Bonnie J. Buratti, G. J. A. Hansen, T. B. McCord, P. D. Nicholson, K. H. Baines
Questa Baseline and Pre-mining Ground-Water Quality Investigation, 7. A Pictorial Record of Chemical Weathering, Erosional Processes, and Potential Debris-flow Hazards in Scar Areas Developed on Hydrothermally Altered Rocks
Erosional scar areas developed along the lower Red River basin, New Mexico, reveal a complex natural history of mineralizing processes, rapid chemical weathering, and intense physical erosion during periodic outbursts of destructive, storm-induced runoff events. The scar areas are prominent erosional features with craggy headwalls and steep, denuded slopes. The largest scar areas...
Authors
Geoffrey S. Plumlee, Steve D. Ludington, Kirk R. Vincent, Philip L. Verplanck, Jonathan Caine, Keith E. Livo
Sample collection of ash and burned soils from the October 2007 southern California Wildfires
Between November 2 through 9, 2007 scientists from the U.S. Geological Survey (USGS) collected samples of ash and burned soils from 28 sites in six areas burned as a result of the Southern California wildfires of October 2007, including the Harris, Witch, Santiago, Ammo, Canyon, and Grass Valley Fires. The primary goal of this sampling and analysis effort was to understand how...
Authors
Todd M. Hoefen, Raymond F. Kokaly, Deborah A. Martin, Carlton J. Rochester, Geoffrey S. Plumlee, Gregory Mendez, Eric G. Reichard, Robert N. Fisher
Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse
Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions...
Authors
Geoffrey S. Plumlee, Philip L. Hageman, Paul J. Lamothe, Thomas L. Ziegler, Gregory P. Meeker, Peter M. Theodorakos, Isabelle K. Brownfield, Monique Adams, Gregg A. Swayze, Todd M. Hoefen, Joseph E. Taggart, Roger N. Clark, S. P. Wilson, Stephen J. Sutley
Materials characterization of dusts generated by the collapse of the World Trade Center
The major inorganic components of the dusts generated from the collapse of the World Trade Center buildings on September 11, 2001 were concrete materials, gypsum, and man-made vitreous fibers. These components were likely derived from lightweight Portland cement concrete floors, gypsum wallboard, and spray-on fireproofing and ceiling tiles, respectively. All of the 36 samples collected...
Authors
Gregory P. Meeker, Stephen J. Sutley, Isabelle K. Brownfield, Heather A. Lowers, Amy M. Bern, Gregg A. Swayze, Todd M. Hoefen, Geoffrey S. Plumlee, Roger N. Clark, Carol A. Gent
Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack
The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over the World Trade Center area on September 16, 18, 22, and 23, 2001. The data were used to map the WTC debris plume and its contents, including the spectral signatures of asbestiform minerals. Samples were collected and used as ground truth for the AVARIS mapping. A number of thermal hot spots were observed with...
Authors
Roger N. Clark, Gregg A. Swayze, Todd M. Hoefen, Robert Green, Keith E. Livo, Gregory P. Meeker, Stephen J. Sutley, Geoffrey S. Plumlee, Betina Pavri, Charles M. Sarture, Joe Boardman, Isabelle K. Brownfield, Laurie C. Morath
Detection of adsorbed water and hydroxyl on the moon
Data from the Visual and Infrared Mapping Spectrometer (VIAAS) on Cassini during its flyby of the AAoon in 1999 show a broad absorption at 3 micrometers due to adsorbed water and near 2.8 micrometers attributed to hydroxyl in the sunlit surface on the AAoon. The amounts of water indicated in the spectra depend on the type of mixing and the grain sizes in the rocks and soils but could be...
Authors
R. N. Clark
Photometric changes on Saturn's Titan: Evidence for active cryovolcanism
We report infrared spectrophotometric variability on the surface of Saturn's moon Titan detected in images returned by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini Saturn Orbiter. The changes were observed at 7°S, 138°W and occurred between October 27, 2005 and January 15, 2006. After that date the surface was unchanged until the most recent observation, March...
Authors
Robert M. Nelson, Lucas W. Kamp, Rosaly M.C. Lopes, Dennis L. Matson, Randolph L. Kirk, Bruce W. Hapke, Stephen D. Wall, Mark D. Boryta, Frank E. Leader, William D. Smythe, Karl L. Mitchell, Kevin H. Baines, Ralf Jaumann, Christophe Sotin, Roger N. Clark, Dale P. Cruikshank, Pierre Drossart, Jonathan I. Lunine, Michel Combes, Giancarlo Bellucci, Jean-Pierre Bibring, Fabrizio Capaccioni, Pricilla Cerroni, Angioletta Coradini, Vittorio Formisano, Gianrico Filacchione, Yves Langevin, Thomas B. McCord, Vito Mennella, Philip D. Nicholson, Bruno Sicardy, Patrick G.J. Irwin, John C. Pearl
VIMS spectral mapping observations of Titan during the Cassini prime mission
This is a data paper designed to facilitate the use of and comparisons to Cassini/visual and infrared mapping spectrometer (VIMS) spectral mapping data of Saturn's moon Titan. We present thumbnail orthographic projections of flyby mosaics from each Titan encounter during the Cassini prime mission, 2004 July 1 through 2008 June 30. For each flyby we also describe the encounter geometry...
Authors
J. W. Barnes, J.M. Soderblom, R. H. Brown, Bonnie J. Buratti, Christophe Sotin, K. H. Baines, R. N. Clark, R. Jaumann, T. B. McCord, R. William Nelson, Stephane Le Mouélic, S. Rodriguez, C. Griffith, P.F. Penteado, F. Tosi, K.M. Pitman, L. A. Soderblom, K. Stephan, P. O. Hayne, G. Vixie, J.-P. Bibring, G. Bellucci, F. Capaccioni, Pricilla Cerroni, Angioletta Coradini, D. P. Cruikshank, Pierre Drossart, V. Formisano, Y. Langevin, D. L. Matson, P. D. Nicholson, Bruno Sicardy
Saturn's north polar cyclone and hexagon at depth revealed by Cassini/VIMS
A high-speed cyclonic vortex centered on the north pole of Saturn has been revealed by the visual-infrared mapping spectrometer (VIMS) onboard the Cassini-Huygens Orbiter, thus showing that the tropospheres of both poles of Saturn are occupied by cyclonic vortices with winds exceeding 135 m/s. High-spatial-resolution (~200 km per pixel) images acquired predominantly under night-time...
Authors
K. H. Baines, T.W. Momary, L.N. Fletcher, A.P. Showman, M. Roos-Serote, R. H. Brown, Bonnie J. Buratti, R. N. Clark, P. D. Nicholson
Fossils, lithologies, and geophysical logs of the Mancos Shale from core hole USGS CL-1 in Montrose County, Colorado
As part of a multidisciplinary investigation of Mancos Shale landscapes in the Gunnison Gorge National Conservation Area in Delta and Montrose Counties of western Colorado by the U.S. Geological Survey, Bureau of Land Management, and Bureau of Reclamation, a core of the Upper Cretaceous Mancos Shale was obtained from a borehole, USGS CL-1, in NE1/4 sec. 8, T. 50 N., R. 9 W....
Authors
Bridget A. Ball, W.A. Cobban, Edward A. Merewether, Richard I. Grauch, K.C. McKinney, Keith E. Livo