Publications
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The role of shear and tensile failure in dynamically triggered landslides
Dynamic stresses generated by earthquakes can trigger landslides. Current methods of landslide analysis such as pseudo-static analysis and Newmark's method focus on the effects of earthquake accelerations on the landslide mass to characterize dynamic landslide behaviour. One limitation of these methods is their use Mohr-Coulomb failure criteria, which only accounts for shear failure, but the role
Authors
T.L. Gipprich, R.K. Snieder, R. W. Jibson, W. Kimman
An exact solution for ideal dam-break floods on steep slopes
The shallow‐water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce an exact analytical solution expressed in terms of readily evaluat
Authors
C. Ancey, Richard M. Iverson, M. Rentschler, Roger P. Denlinger
A comparative analysis of simulated and observed landslide locations triggered by Hurricane Camille in Nelson County, Virginia
In 1969, Nelson County, Virginia received up to 71 cm of rain within 12 h starting at 7 p.m. on August 19. The total rainfall from the storm exceeded the 1000-year return period in the region. Several thousands of landslides were induced by rainfall associated with Hurricane Camille causing fatalities and destroying infrastructure. We apply a distributed transient response model for regional slope
Authors
M.M. Morrissey, G. F. Wieczorek, B. A. Morgan
HiRISE observations of fractured mounds: Possible Martian pingos
Early images from the High Resolution Imaging Science Experiment (HiRISE) camera have revealed small fractured mounds in the Martian mid‐latitudes. HiRISE resolves fractures on the mound surfaces, indicating uplift, and shows that the mound surface material resembles that of the surrounding landscape. Analysis of Mars Orbiter Camera (MOC) images shows that in Utopia Planitia the mounds lie almost
Authors
Colin M. Dundas, Michael T. Mellon, Alfred S. McEwen, Alexandra Lefort, Laszlo P. Keszthelyi, Nicolas Thomas
Titan's inventory of organic surface materials
Cassini RADAR observations now permit an initial assessment of the inventory of two classes, presumed to be organic, of Titan surface materials: polar lake liquids and equatorial dune sands. Several hundred lakes or seas have been observed, of which dozens are each estimated to contain more hydrocarbon liquid than the entire known oil and gas reserves on Earth. Dark dunes cover some 20% of Titan's
Authors
Ralph D. Lorenz, Karl L. Mitchell, Randolph L. Kirk, Alexander G. Hayes, Oded Aharonson, Howard A. Zebker, Philipe Paillou, Jani Radebaugh, Jonathan I. Lunine, Michael A. Janssen, Stephen D. Wall, Rosaly M.C. Lopes, Bryan Stiles, Steven J. Ostro, Giuseppe Mitri, Ellen R. Stofan
Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them
Displacement–length data from faults, joints, veins, igneous dikes, shear deformation bands, and compaction bands define two groups. The first group, having a power-law scaling relation with a slope of n = 1 and therefore a linear dependence of maximum displacement and discontinuity length (Dmax = γL), comprises faults and shear (non-compactional or non-dilational) deformation bands. These shearin
Authors
Richard A. Schultz, Roger Soliva, Haakon Fossen, Chris Okubo, Donald M. Reeves
Modeling the spatial distribution of landslide-prone colluvium and shallow groundwater on hillslopes of Seattle, WA
Landslides in partially saturated colluvium on Seattle, WA, hillslopes have resulted in property damage and human casualties. We developed statistical models of colluvium and shallow-groundwater distributions to aid landslide hazard assessments. The models were developed using a geographic information system, digital geologic maps, digital topography, subsurface exploration results, the groundwate
Authors
W.H. Schulz, D. J. Lidke, J. W. Godt
Kaguyak dome field and its Holocene caldera, Alaska Peninsula
Kaguyak Caldera lies in a remote corner of Katmai National Park, 375 km SW of Anchorage, Alaska. The 2.5-by-3-km caldera collapsed ~ 5.8 ± 0.2 ka (14C age) during emplacement of a radial apron of poorly pumiceous crystal-rich dacitic pyroclastic flows (61–67% SiO2). Proximal pumice-fall deposits are thin and sparsely preserved, but an oxidized coignimbrite ash is found as far as the Valley of Ten
Authors
J. Fierstein, W. Hildreth
Dunes on Titan observed by Cassini Radar
Thousands of longitudinal dunes have recently been discovered by the Titan Radar Mapper on the surface of Titan. These are found mainly within ±30° of the equator in optically-, near-infrared-, and radar-dark regions, indicating a strong proportion of organics, and cover well over 5% of Titan's surface. Their longitudinal duneform, interactions with topography, and correlation with other aeolian f
Authors
J. Radebaugh, R. D. Lorenz, J. I. Lunine, S. D. Wall, G. Boubin, E. Reffet, Randolph L. Kirk, R.M. Lopes, E. R. Stofan, Laurence A. Soderblom, M. Allison, M. Janssen, P. Paillou, P. Callahan, C. Spencer
Dynamic stresses, Coulomb failure, and remote triggering
Dynamic stresses associated with crustal surface waves with 15-30-sec periods and peak amplitudes < 1 MPa are capable of triggering seismicity at sites remote from the generating mainshock under appropriate conditions. Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid-onset triggered seismicity that develop during the surface-wave peak dyn
Authors
David P. Hill
Permeability of continental crust influenced by internal and external forcing
The permeability of continental crust is so highly variable that it is often considered to defy systematic characterization. However, despite this variability, some order has been gleaned from globally compiled data. What accounts for the apparent coherence of mean permeability in the continental crust (and permeability–depth relations) on a very large scale? Here we argue that large‐scale crustal
Authors
S.A. Rojstaczer, S. E. Ingebritsen, D.O. Hayba
Upper conduit structure and explosion dynamics at Stromboli
Modeling of very long period seismic data recorded during explosive activity at Stromboli in 1997 provides an image of the uppermost 1 km of its volcanic plumbing system. Two distinct dike-like conduit structures are identified, each representative of explosive eruptions from two different vents located near the northern and southern perimeters of the summit crater. Inferred volumetric changes in
Authors
Bernard A. Chouet, Phillip B. Dawson, Marcello Martini