A5042928943- Landslides and related hazards
- Soil and Unsaturated Flow
- Hydrology and Sediment Transport Processes
- earthquake and tectonic studies
- Cryospheric studies and observations
- Granular flow and fluidized beds
- Dam Engineering and Safety
- Fire effects on ecosystems
- Geotechnical Engineering and Analysis
- Rock Mechanics and Modeling
- Groundwater flow and contamination studies
- Soil erosion and sediment transport
- Seismology and Earthquake Studies
- Geotechnical and Geomechanical Engineering
- Tree Root and Stability Studies
- Geotechnical Engineering and Soil Mechanics
- Flood Risk Assessment and Management
- Aeolian processes and effects
- Geological and Geochemical Analysis
- Lattice Boltzmann Simulation Studies
- Geology and Paleoclimatology Research
- Hydrology and Watershed Management Studies
- Computational Physics and Python Applications
- Plasma Diagnostics and Applications
- Climate change and permafrost
United States Geological Survey
2013-2024
Cascades Volcano Observatory
1998-2021
Google (United States)
2014
SLAC National Accelerator Laboratory
2012
Iowa State University
2008
Florida State University
2002
Stanford University
1980-1981
Recent advances in theory and experimentation motivate a thorough reassessment of the physics debris flows. Analyses flows dry, granular solids solid‐fluid mixtures provide foundation for comprehensive flow theory, experiments data that reveal strengths limitations theoretical models. Both materials dry can sustain shear stresses while remaining static; both deform slow, tranquil mode characterized by enduring, frictional grain contacts; more rapid, agitated brief, inelastic collisions. In...
Landsliding in response to rainfall involves physical processes that operate on disparate timescales. Relationships between these timescales guide development of a mathematical model uses reduced forms Richards equation evaluate effects infiltration landslide occurrence, timing, depth, and acceleration diverse situations. The longest pertinent timescale is A / D 0 , where the maximum hydraulic diffusivity soil catchment area potentially affects groundwater pressures at prospective slip...
▪ Abstract Field observations, laboratory experiments, and theoretical analyses indicate that landslides mobilize to form debris flows by three processes: (a) widespread Coulomb failure within a sloping soil, rock, or sediment mass, (b) partial complete liquefaction of the mass high pore-fluid pressures, (c) conversion landslide translational energy internal vibrational (i.e. granular temperature). These processes can operate independently, but in many circumstances they appear...
Rock avalanches, debris flows, and related phenomena consist of grain‐fluid mixtures that move across three‐dimensional terrain. In all these the same basic forces govern motion, but differing mixture compositions, initial conditions, boundary conditions yield varied dynamics deposits. To predict motion diverse masses from initiation to deposition, we develop a depth‐averaged, mathematical model accounts explicitly for solid‐ fluid‐phase interactions. Model input consists path topography,...
Research Article| August 01, 1998 Objective delineation of lahar-inundation hazard zones Richard M. Iverson; Iverson 1U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar Steven P. Schilling; Schilling James W. Vallance 2Department Civil Engineering and Applied Mechanics, McGill University, Montreal, Quebec H3A 2K6, Canada Author Article Information Publisher: Society America...
Aggregation of data collected in 28 controlled experiments reveals reproducible debris‐flow behavior that provides a clear target for model tests. In each experiment ∼10 m 3 unsorted, water‐saturated sediment composed mostly sand and gravel discharged from behind gate, descended steep, 95‐m flume, formed deposit on nearly horizontal runout surface. Experiment subsets were distinguished by differing basal boundary conditions (1 versus 16 mm roughness heights) mud contents 7 percent dry...
Numerical solutions of the equations describing flow variably fluidized Coulomb mixtures predict key features dry granular avalanches and water‐saturated debris flows measured in physical experiments. These include time‐dependent speeds, depths, widths as well geometry resulting deposits. Three‐dimensional (3‐D) boundary surfaces strongly influence dynamics because transverse shearing cross‐stream momentum transport occur where topography obstructs or redirects motion. Consequent energy...
Some landslides move imperceptibly downslope, whereas others accelerate catastrophically. Experimental triggered by rising pore water pressure moved at sharply contrasting rates due to small differences in initial porosity. Wet sandy soil with porosity of about 0.5 contracted during slope failure, partially liquefied, and accelerated within 1 second speeds over meter per second. The same 0.4 dilated failure slipped episodically averaging 0.002 Repeated slip episodes were induced gradually...
Landslides reflect landscape instability that evolves over meteorological and geological timescales, they also pose threats to people, property, the environment. The severity of these depends largely on landslide speed travel distance, which are collectively described as "mobility". To investigate causes effects mobility, we focus a disastrous occurred 22 March 2014 near Oso, Washington, USA, following long period abnormally wet weather. landslide's impacts were severe because its mobility...
To simulate debris-flow behaviour from initiation to deposition, we derive a depth-averaged, two-phase model that combines concepts of critical-state soil mechanics, grain-flow mechanics and fluid mechanics. The model's balance equations describe coupled evolution the solid volume fraction, m , basal pore-fluid pressure, flow thickness two components velocity. Basal friction is evaluated using generalized Coulomb rule, motion in frame reference translates with velocity granular phase, v s ....
Data from large‐scale debris‐flow experiments are combined with modeling of particle‐size segregation to explain the formation lateral levees enriched in coarse grains. The experimental flows consisted 10 m 3 water‐saturated sand and gravel, which traveled ∼80 down a steeply inclined flume before forming an elongated leveed deposit long on nearly horizontal runout surface. We measured surface velocity field observed sequence deposition by seeding tracers onto flow tracking them video...
Abstract Earth‐surface mass flows such as debris flows, rock avalanches, and dam‐break floods can grow greatly in size destructive potential by entraining bed material they encounter. Increasing use of depth‐integrated momentum conservation equations to model these erosive motivates a review the underlying theory. Our indicates that many existing models apply principles incorrectly, leading spurious inferences about role exchanges at flow‐bed boundaries. Model discrepancies be rectified...
Analyses of mass and momentum exchange between a debris flow or avalanche an underlying sediment layer aid interpretations predictions bed‐sediment entrainment rates. A preliminary analysis assesses the behavior Coulomb slide block that entrains bed material as it descends uniform slope. The demonstrates block's can grow unstably, even in presence limited efficiency. more‐detailed, depth‐integrated continuum interacting, deformable bodies identifies mechanical controls on efficiency, shows...
We evaluate a new depth-averaged mathematical model that is designed to simulate all stages of debris-flow motion, from initiation deposition. A companion paper shows how the model's five governing equations describe simultaneous evolution flow thickness, solid volume fraction, basal pore-fluid pressure and two components momentum. Each equation contains source term represents influence state-dependent granular dilatancy. Here, we recapitulate analyse their eigenstructure show they form...
Research Article| October 01, 1999 Debris-flow deposition: Effects of pore-fluid pressure and friction concentrated at flow margins Jon J. Major; Major 1U.S. Geological Survey, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar Richard M. Iverson Author Article Information Publisher: Society America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print 0016-7606 GSA Bulletin (1999) 111 (10): 1424–1434....
Research Article| February 01, 2001 New views of granular mass flows Richard M. Iverson; Iverson 1U.S. Geological Survey, 5400 MacArthur Boulevard, Vancouver, Washington 98661, USA Search for other works by this author on: GSW Google Scholar James W. Vallance 2Department Civil Engineering and Applied Mechanics, McGill University, Montreal, Quebec H3A 2FK6, Canada Author Article Information Publisher: Society America Received: 02 Jun 2000 Revision 16 Oct Accepted: 25 First Online: 2017 Online...
A new mathematical model clarifies how diverse styles and rates of landslide motion can result from regulation Coulomb friction by dilation or contraction water‐saturated basal shear zones. Normalization the equations shows that feedback due to coupling between motion, zone volume change, pore pressure change depends on a single dimensionless parameter α, which, in turn, dilatancy angle ψ intrinsic timescales for generation dissipation. If soil contracts during slope failure, then α < 0,...
Results of a single‐blind round‐robin comparison satellite primary productivity algorithms are presented. The goal the exercise was to determine accuracy in predicting depth‐integrated production from information amenable remote sensing. Twelve algorithms, developed by 10 teams, were evaluated comparing their ability estimate daily (IP, mg C m −2 ) at 89 stations geographically diverse provinces. Algorithms furnished about surface chlorophyll concentration, temperature, photosynthetic...
To establish a theoretical basis for predicting and interpreting the behavior of rapid mass movements on Earth's surface, we develop test new computational model gravity‐driven motion granular avalanches across irregular, three‐dimensional (3‐D) terrain. The principles embodied in are simple few: continuum momentum conservation intergranular stress generation governed by Coulomb friction. However, significant challenges result from necessity satisfying these when deforming interact with...
Research Article| October 01, 1987 Rainfall, ground-water flow, and seasonal movement at Minor Creek landslide, northwestern California: Physical interpretation of empirical relations RICHARD M. IVERSON; IVERSON 1U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Blvd., Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar JON J. MAJOR Author Article Information Publisher: Society America First Online: 01 Jun 2017 Online ISSN: 1943-2674...
Results from two types of experiments show that intergranular pore pressures fluctuated dynamically during rapid, steady shear deformation water-saturated granular materials. During some fluctuations, the water locally supported all normal and stresses, while grain-contact stresses transiently fell to zero. Fluctuations also propagated outward zone; this process modifies in adjacent areas potentially instigates shear-zone growth.
Scaling considerations indicate that miniature experiments can be used to test models of granular avalanches in which the effects intergranular fluid and cohesion are negligible. To predictions a avalanche model described companion paper, we performed bench top involving dry sand across irregular basal topography mimicked complexity natural terrain. The employed novel method laser‐assisted cartography map three‐dimensional morphology rapidly moving avalanches, thereby providing...