Publications
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Quasi-periodic bedding in the sedimentary rock record of mars
Widespread sedimentary rocks on Mars preserve evidence of surface conditions different from the modern cold and dry environment, although it is unknown how long conditions favorable to deposition persisted. We used 1-meter stereo topographic maps to demonstrate the presence of rhythmic bedding at several outcrops in the Arabia Terra region. Repeating beds are ∼10 meters thick, and one site contain
Authors
Kevin W. Lewis, Oded Aharonson, John P. Grotzinger, Randolph L. Kirk, Alfred S. McEwen, Terry-Ann Suer
Volatile emissions and gas geochemistry of Hot Spring Basin, Yellowstone National Park, USA
We characterize and quantify volatile emissions at Hot Spring Basin (HSB), a large acid-sulfate region that lies just outside the northeastern edge of the 640 ka Yellowstone Caldera. Relative to other thermal areas in Yellowstone, HSB gases are rich in He and H2, and mildly enriched in CH4 and H2S. Gas compositions are consistent with boiling directly off a deep geothermal liquid at depth as it mi
Authors
C. Werner, S. Hurwitz, William C. Evans, J. B. Lowenstern, D. Bergfeld, H. Heasler, C. Jaworowski, A. Hunt
Multiple plagioclase crystal populations identified by crystal size distribution and in situ chemical data: Implications for timescales of magma chamber processes associated with the 1915 eruption of Lassen Peak, CA
Products of the 1915 Lassen Peak eruption reveal evidence for a magma recharge–magma mixing event that may have catalyzed the eruption and from which four compositional members were identified: light dacite, black dacite, andesitic inclusion, and dark andesite. Crystal size distribution, textural, and in situ chemical (major and trace element and Sr isotope) data for plagioclase from these composi
Authors
M.J. Salisbury, W. A. Bohrson, M.A. Clynne, F.C. Ramos, P. Hoskin
4D volcano gravimetry
Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful evaluation
Authors
Maurizio Battaglia, J. Gottsmann, D. Carbone, J. Fernandez
Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing
Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986, respectively. Based on the CO2(aq)profiles through time, the CO2 content
Authors
M. Kusakabe, T. Ohba, Issa, Y. Yoshida, H. Satake, T. Ohizumi, William C. Evans, G. Tanyileke, G.W. Kling
Guidelines for landslide susceptibility, hazard and risk zoning for land-use planning
[No abstract available]
Authors
R. Fell, J. Corominas, C. Bonnard, L. Cascini, E. Leroi, W. Z. Savage
Fluvial channels on Titan: Initial Cassini RADAR observations
Cassini radar images show a variety of fluvial channels on Titan's surface, often several hundreds of kilometers in length. Some (predominantly at low- and mid-latitude) are radar-bright and braided, resembling desert washes where fines have been removed by energetic surface liquid flow, presumably from methane rainstorms. Others (predominantly at high latitudes) are radar-dark and meandering and
Authors
R. D. Lorenz, R.M. Lopes, F. Paganelli, J. I. Lunine, Randolph L. Kirk, K. L. Mitchell, Laurence A. Soderblom, E. R. Stofan, G. Ori, M. Myers, H. Miyamoto, J. Radebaugh, B. Stiles, S. D. Wall, C. A. Wood
Oxygen isotope geochemistry of the lassen volcanic center, California: Resolving crustal and mantle contributions to continental Arc magmatism
This study reports oxygen isotope ratios determined by laser fluorination of mineral separates (mainly plagioclase) from basaltic andesitic to rhyolitic composition volcanic rocks erupted from the Lassen Volcanic Center (LVC), northern California. Plagioclase separates from nearly all rocks have δ18O values (6·1–8·4‰) higher than expected for production of the magmas by partial melting of little e
Authors
T.C. Feeley, M.A. Clynne, G.S. Winer, W.C. Grice
Viscoelastic love-type surface waves
The general theoretical solution for Love-Type surface waves in viscoelastic media provides theoreticalexpressions for the physical characteristics of the waves in elastic as well as anelastic media with arbitraryamounts of intrinsic damping. The general solution yields dispersion and absorption-coefficient curves for the waves as a function of frequency and theamount of intrinsic damping for any
Authors
Roger D. Borcherdt
High Resolution Imaging Science Experiment (HiRISE) observations of glacial and periglacial morphologies in the circum-Argyre Planitia highlands, Mars
The landscape of the Argyre Planitia and adjoining Charitum and Nereidum Montes in the southern hemisphere of Mars has been heavily modified since formation of the Argyre impact basin. This study examines morphologies in the Argyre region revealed in images acquired by the High Resolution Imaging Science Experiment (HiRISE) camera and discusses the implications for glacial and periglacial processe
Authors
Maria E. Banks, Alfred S. McEwen, Jeffrey S. Kargel, Victor R. Baker, Robert G. Strom, Michael T. Mellon, Virginia C. Gulick, Laszlo P. Keszthelyi, Kenneth E. Herkenhoff, Jon D. Pelletier, Windy L. Jaeger
Landslides and engineering geology of the Seattle, Washington, area
This volume brings together case studies and summary papers describing the application of state-of-the-art engineering geologic methods to landslide hazard analysis for the Seattle, Washington, area. An introductory chapter provides a thorough description of the Quaternary and bedrock geology of Seattle. Nine additional chapters review the history of landslide mapping in Seattle, present case stud
Authors
Rex L. Baum, Jonathan W. Godt, Lynn M. Highland
Development of the U.S. Geological Survey's PAGER system (Prompt Assessment of Global Earthquakes for Response)
The Prompt Assessment of Global Earthquakes for Response (PAGER) System plays a primary alerting role for global earthquake disasters as part of the U.S. Geological Survey’s (USGS) response protocol. We provide an overview of the PAGER system, both of its current capabilities and our ongoing research and development. PAGER monitors the USGS’s near real-time U.S. and global earthquake origins and a
Authors
D. J. Wald, P.S. Earle, T.I. Allen, K. Jaiswal, K. Porter, M. Hearne