Publications
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Rain, winds and haze during the Huygens probe's descent to Titan's surface Rain, winds and haze during the Huygens probe's descent to Titan's surface
The irreversible conversion of methane into higher hydrocarbons in Titan's stratosphere implies a surface or subsurface methane reservoir. Recent measurements from the cameras aboard the Cassini orbiter fail to see a global reservoir, but the methane and smog in Titan's atmosphere impedes the search for hydrocarbons on the surface. Here we report spectra and high-resolution images...
Authors
M.G. Tomasko, B. Archinal, T. Becker, B. Bezard, M. Bushroe, M. Combes, D. Cook, A. Coustenis, C. De Bergh, L.E. Dafoe, L. Doose, S. Doute, A. Eibl, S. Engel, F. Gliem, B. Grieger, K. Holso, E. Howington-Kraus, E. Karkoschka, H.U. Keller, Randolph L. Kirk, R. Kramm, M. Kuppers, P. Lanagan, E. Lellouch, M. Lemmon, J. Lunine, E. McFarlane, J. Moores, G.M. Prout, B. Rizk, M. Rosiek, P. Rueffer, S.E. Schroder, B. Schmitt, C. See, P. Smith, Laurence A. Soderblom, N. Thomas, R. West
The carbon dioxide cycle The carbon dioxide cycle
The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor.
Authors
Philip B. James, Gary B. Hansen, Timothy N. Titus
Ongoing hydrothermal heat loss from the 1912 ash-flow sheet, Valley of Ten Thousand Smokes, Alaska Ongoing hydrothermal heat loss from the 1912 ash-flow sheet, Valley of Ten Thousand Smokes, Alaska
The June 1912 eruption of Novarupta filled nearby glacial valleys on the Alaska Peninsula with ash-flow tuff (ignimbrite), and post-eruption observations of thousands of steaming fumaroles led to the name ‘Valley of Ten Thousand Smokes’ (VTTS). By the late 1980s most fumarolic activity had ceased, but the discovery of thermal springs in mid-valley in 1987 suggested continued cooling of...
Authors
N. Hogeweg, T. E. C. Keith, E.M. Colvard, S. E. Ingebritsen
The May 2003 eruption of Anatahan volcano, Mariana Islands: Geochemical evolution of a silicic island-arc volcano The May 2003 eruption of Anatahan volcano, Mariana Islands: Geochemical evolution of a silicic island-arc volcano
The first historical eruption of Anatahan volcano began on May 10, 2003. Samples of tephra from early in the eruption were analyzed for major and trace elements, and Sr, Nd, Pb, Hf, and O isotopic compositions. The compositions of these tephras are compared with those of prehistoric samples of basalt and andesite, also newly reported here. The May 2003 eruptives are medium-K andesites...
Authors
J.A. Wade, T. Plank, R. J. Stern, D.L. Tollstrup, J.B. Gill, J. C. O’Leary, J.M. Eiler, R. B. Moore, J.D. Woodhead, F. Trusdell, T.P. Fischer, David R. Hilton
Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site
The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind. Regolith (unconsolidated surface material) at the Mars Exploration...
Authors
R. Sullivan, D. Banfield, J.F. Bell, W. Calvin, D. Fike, M. Golombek, R. Greeley, J. Grotzinger, Kenneth E. Herkenhoff, D. Jerolmack, M. Malin, D. Ming, Laurence A. Soderblom, S. W. Squyres, S. Thompson, W.A. Watters, C.M. Weitz, A. Yen
Locations and descriptions of gravity, box, and push cores collected in San Francisco Bay between January and February, 1990 and 1991 Locations and descriptions of gravity, box, and push cores collected in San Francisco Bay between January and February, 1990 and 1991
A project to study San Francisco Bay sediments collected over 300 sediment gravity cores; six push cores, and three box cores in San Francisco Bay during the years 1990-91. The purpose of the sampling effort is to establish a database on the Holocene sediment history of the bay. The samples described and mapped are the first effort to catalog and present the data collected. Thus far the...
Authors
Roberto J. Anima, H. Edward Clifton, Carol Reiss, Florence L. Wong
Thermal observations of gas pistoning at Kilauea Volcano Thermal observations of gas pistoning at Kilauea Volcano
Data acquired by three continuously recording thermal infrared thermometers situated on the north rim of Pu'u'O' o Crater at Kilauea Volcano during 2002 revealed episodes of periodic thermal pulses originating from a degassing vent on the crater floor. These thermal pulses are interpreted as gas release (jetting events) associated with gas pistoning, a mechanism observed previously at...
Authors
J.B. Johnson, A.J.L. Harris, R. Hoblitt
An updated global earthquake catalogue for stable continental regions: Reassessing the correlation with ancient rifts An updated global earthquake catalogue for stable continental regions: Reassessing the correlation with ancient rifts
We present an updated global earthquake catalogue for stable continental regions (SCRs; i.e. intraplate earthquakes) that is available on the Internet. Our database contains information on location, magnitude, seismic moment and focal mechanisms for over 1300 M (moment magnitude) ≥ 4.5 historic and instrumentally recorded crustal events. Using this updated earthquake database in...
Authors
S.M. Schulte, Walter D. Mooney
The controlling effect of viscous dissipation on magma flow in silicic conduits The controlling effect of viscous dissipation on magma flow in silicic conduits
Nearly all volcanic conduit models assume that flow is Newtonian and isothermal. Such models predict that, during high-flux silicic eruptions, gradients in pressure with depth increase upward as magma accelerates and becomes more viscous, leading to extremely low pressure and fragmentation at a depth of kilometers below the surface. In this paper I show that shear heating, also known as...
Authors
L.G. Mastin
Thermal infrared and visual observations of a water ice lag in the Mars southern summer Thermal infrared and visual observations of a water ice lag in the Mars southern summer
We present thermal infrared and visual evidence for the existence of water ice lags in the early southern summer. The observed H2O‐ice lags lay in and near a chasma and appears to survive between 6–8 sols past the sublimation of the CO2. Possible sources of the H2O that compose the lag are (1) atmospheric H2O that is incorporated into the seasonal cap during condensation, (2) cold...
Authors
Timothy N. Titus
Regulation of landslide motion by dilatancy and pore pressure feedback Regulation of landslide motion by dilatancy and pore pressure feedback
A new mathematical model clarifies how diverse styles and rates of landslide motion can result from regulation of Coulomb friction by dilation or contraction of water‐saturated basal shear zones. Normalization of the model equations shows that feedback due to coupling between landslide motion, shear zone volume change, and pore pressure change depends on a single dimensionless parameter...
Authors
R.M. Iverson
The Zamama-Thor region of Io: Insights from a synthesis of mapping, topography, and Galileo spacecraft data The Zamama-Thor region of Io: Insights from a synthesis of mapping, topography, and Galileo spacecraft data
We have studied data from the Galileo spacecraft's three remote sensing instruments (Solid-State Imager (SSI), Near-Infrared Mapping Spectrometer (NIMS), and Photopolarimeter-Radiometer (PPR)) covering the Zamama–Thor region of Io's antijovian hemisphere, and produced a geomorphological map of this region. This is the third of three regional maps we are producing from the Galileo...
Authors
David A. Williams, Laszlo P. Keszthelyi, Paul M. Schenk, Moses P. Milazzo, Rosaly Lopes, Julie A. Rathbun, Ronald Greeley