Richard M. Iverson
My USGS career has focused mostly on evaluating and modeling the dynamics and hazards of landslides and debris flows, with a secondary focus on the dynamics of volcanic extrusions. Part of my work involved design, development, and utilization of the USGS debris-flow flume, a unique, large-scale experimental facility at the H.J. Andrews Experimental Forest near Blue River, Oregon.
Career Highlights
A written account of some career highlights was published in 2020 in Perspectives of Earth and Space Scientists. An oral history interview recounting some of my career highlights is archived at Oregon State University.
Professional Experience
Senior Research Hydrologist, USGS Cascades Volcano Observatory
Adjunct Professor, University of Washington and Portland State University
Education and Certifications
Stanford University, Ph.D., 1984, Applied Earth Sciences
Stanford University, M.S., 1981, Hydrology
Stanford University, M.S., 1980, Applied Earth Sciences
Iowa State University, B.S., 1977, Geology major, Mathematics and Physics minors
Honors and Awards
Fellow, American Geophysical Union (AGU) and Geological Society of America (GSA)
E.B. Burwell Award, GSA, 1991
Kirk Bryan Award, GSA, 2001
Richard H. Jahns Distinguished Lecturer, GSA, 2005
Langbein Lecturer, AGU, 2006
U.S. Department of the Interior Distinguished Service Award, 2019
Science and Products
My research career, including information about the debris flow experimental flume facility, is docuymented in this memoir.
Landslide disparities, flume discoveries, and Oso despair
Landslide mobility and hazards: implications of the 2014 Oso disaster
Entrainment of bed material by Earth-surface mass flows: review and reformulation of depth-integrated theory
A depth-averaged debris-flow model that includes the effects of evolving dilatancy. I. Physical basis
Debris flows: Behavior and hazard assessment
A depth-averaged debris-flow model that includes the effects of evolving dilatancy: II. Numerical predictions and experimental tests.
Discussion: Numerical study on the entrainment of bed material into rapid landslides
Elementary theory of bed-sediment entrainment by debris flows and avalanches
Grain-size segregation and levee formation in geophysical mass flows
Mechanics of debris flows and rock avalanches: Chapter 43
Entrainment of bed sediment by debris flows: results from large-scale experiments
A two-phase debris-flow model that includes coupled evolution of volume fractions, granular dilatancy, and pore-fluid pressure
Positive feedback and momentum growth during debris-flow entrainment of wet bed sediment
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Data
- Publications
My research career, including information about the debris flow experimental flume facility, is docuymented in this memoir.
Landslide disparities, flume discoveries, and Oso despair
Landslide dynamics is the branch of science that seeks to understand the motion of landslides by applying Newton's laws. This memoir focusses on a 40‐year effort to understand motion of highly mobile—and highly lethal—landslides such as debris avalanches and debris flows. A major component of this work entailed development and operation of the U.S. Geological Survey debris flow flume, a unique, laAuthorsRichard M. IversonFilter Total Items: 118Landslide mobility and hazards: implications of the 2014 Oso disaster
Landslides reflect landscape instability that evolves over meteorological and geological timescales, and they also pose threats to people, property, and the environment. The severity of these threats depends largely on landslide speed and travel distance, which are collectively described as landslide “mobility”. To investigate causes and effects of mobility, we focus on a disastrous landslide thatAuthorsRichard M. Iverson, David L. George, Kate E. Allstadt, Mark E. Reid, Brian D. Collins, James W. Vallance, Steve P. Schilling, Jonathan W. Godt, Charles Cannon, Christopher S. Magirl, Rex L. Baum, Jeffrey A. Coe, William Schulz, J. Brent BowerEntrainment of bed material by Earth-surface mass flows: review and reformulation of depth-integrated theory
Earth-surface mass flows such as debris flows, rock avalanches, and dam-break floods can grow greatly in size and destructive potential by entraining bed material they encounter. Increasing use of depth-integrated mass- and momentum-conservation equations to model these erosive flows motivates a review of the underlying theory. Our review indicates that many existing models apply depth-integratedAuthorsRichard M. Iverson, Chaojun OuyangA depth-averaged debris-flow model that includes the effects of evolving dilatancy. I. Physical basis
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 of the solid volume fraction, m, basal pore-fluid pressure, flow thickness and two components of flow velocity. Basal friction is evaluAuthorsRichard M. Iverson, David L. GeorgeDebris flows: Behavior and hazard assessment
Debris flows are water-laden masses of soil and fragmented rock that rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form lobate deposits when they spill onto valley floors. Because they have volumetric sediment concentrations that exceed 40 percent, maximum speeds that surpass 10 m/s, and sizes that can range up to ~109 m3, debris flows can denude slopes,AuthorsRichard M. IversonA depth-averaged debris-flow model that includes the effects of evolving dilatancy: II. Numerical predictions and experimental tests.
We evaluate a new depth-averaged mathematical model that is designed to simulate all stages of debris-flow motion, from initiation to deposition. A companion paper shows how the model’s five governing equations describe simultaneous evolution of flow thickness, solid volume fraction, basal pore-fluid pressure, and two components of flow momentum. Each equation contains a source term that representAuthorsDavid L. George, Richard M. IversonDiscussion: Numerical study on the entrainment of bed material into rapid landslides
A paper recently published in this journal (Pirulli & Pastor, 2012) uses numerical modelling to study the important problem of entrainment of bed material by landslides. Unfortunately, some of the basic equations employed in the study are flawed, because they violate the principle of linear momentum conservation. Similar errors exist in some other studies of entrainment, and the errors appear to sAuthorsRichard M. IversonElementary theory of bed-sediment entrainment by debris flows and avalanches
Analyses of mass and momentum exchange between a debris flow or avalanche and an underlying sediment layer aid interpretations and predictions of bed-sediment entrainment rates. A preliminary analysis assesses the behavior of a Coulomb slide block that entrains bed material as it descends a uniform slope. The analysis demonstrates that the block's momentum can grow unstably, even in the presence oAuthorsRichard M. IversonGrain-size segregation and levee formation in geophysical mass flows
Data from large-scale debris-flow experiments are combined with modeling of particle-size segregation to explain the formation of lateral levees enriched in coarse grains. The experimental flows consisted of 10 m3 of water-saturated sand and gravel, which traveled ∼80 m down a steeply inclined flume before forming an elongated leveed deposit 10 m long on a nearly horizontal runout surface. We measAuthorsC.G. Johnson, B. P. Kokelaar, Richard M. Iverson, M. Logan, R.G. LaHusen, J.M.N.T. GrayMechanics of debris flows and rock avalanches: Chapter 43
Debris flows are geophysical phenomena intermediate in character between rock avalanches and flash floods. They commonly originate as water-laden landslides on steep slopes and transform into liquefied masses of fragmented rock, muddy water, and entrained organic matter that disgorge from canyons onto valley floors. Typically including 50%–70% solid grains by volume, attaining speeds >10 m/s, andAuthorsRichard M. IversonEntrainment of bed sediment by debris flows: results from large-scale experiments
When debris flows grow by entraining sediment, they can become especially hazardous owing to increased volume, speed, and runout. To investigate the entrainment process, we conducted eight largescale experiments in the USGS debris-flow flume. In each experiment, we released a 6 m3 water-saturated debris flow across a 47-m long, ~12-cm thick bed of partially saturated sediment lining the 31º flume.AuthorsMark E. Reid, Richard M. Iverson, Matthew Logan, Richard G. LaHusen, Jonathan W. Godt, Julie P. GriswoldA two-phase debris-flow model that includes coupled evolution of volume fractions, granular dilatancy, and pore-fluid pressure
Pore-fluid pressure plays a crucial role in debris flows because it counteracts normal stresses at grain contacts and thereby reduces intergranular friction. Pore-pressure feedback accompanying debris deformation is particularly important during the onset of debrisflow motion, when it can dramatically influence the balance of forces governing downslope acceleration. We consider further effects ofAuthorsDavid L. George, Richard M. IversonPositive feedback and momentum growth during debris-flow entrainment of wet bed sediment
Debris flows typically occur when intense rainfall or snowmelt triggers landslides or extensive erosion on steep, debris-mantled slopes. The flows can then grow dramatically in size and speed as they entrain material from their beds and banks, but the mechanism of this growth is unclear. Indeed, momentum conservation implies that entrainment of static material should retard the motion of the flowsAuthorsRichard M. Iverson, Mark E. Reid, Matthew Logan, Richard G. Lahusen, Jonathan W. Godt, Julia P. GriswoldNon-USGS Publications**
Iverson, R.M., 1980, Processes of accelerated pluvial erosion on desert hillslopes modified by vehicular traffic: Earth Surface Processes, v. 5, no. 4, p. 369‑388.Iverson, R.M., Hinckley, B.S., Webb, R.H., and Hallet, B., 1981, Physical effects of vehicular disturbances on arid landscapes: Science, v. 212, no. 4497, p. 915‑917.Hinckley, B.S., Iverson, R.M., and Hallet, B., 1983, Accelerated water erosion in ORV‑use areas: Environmental Effects of Off-road Vehicles: Impacts and Management in Arid Regions, R.H. Webb and H.G. Wilshire, eds., Springer‑Verlag, New York, p. 81‑94.Elvidge, C.D., and Iverson, R.M., 1983, Regeneration of desert pavement and desert varnish: Environmental Effects of Off-road Vehicles: Impacts and Management in Arid regions, R.H. Webb and H.G. Wilshire, eds., Springer‑Verlag, New York, p. 225‑241.Iverson, R.M., 1983, Discussion of "A model for creeping flow in landslides" by W.Z. Savage and A.F. Chleborad: Bulletin of the Association of Engineering Geologists, v. 20, no. 4, p. 455‑459.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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