I develop mathematical models, numerical methods, and open-source software for simulating geophysical flows. My mathematical focus is PDEs and adaptive finite volume methods, with an application focus on earth-surface flows (e.g., landslides, debris flows, tsunamis, overland flooding).
Current Position:
Research Mathematician, USGS, Cascades Volcano Observatory, 2012-present
Previous Positions:
Mendenhall Postdoctoral Fellow, USGS, Cascades Volcano Observatory, 2008-2012
Postdoctoral Fellow, Department of Applied Mathematics, University of Washington, 2007-2008
Postdoctoral Fellow, Department of Mathematics, University of Utah, 2006-2007.
Education:
Ph.D., Applied Mathematics, University of Washington, Seattle 2006.
M.S., Applied Mathematics, University of Washington, Seattle 2004.
B.S. , B.S. & B.A., Physics, Biology, Anthropology, University of California at Santa Barbara, 1997.
Science and Products
Filter Total Items: 28
Forecasting the inundation of postfire debris flows
In the semi-arid regions of the western United States, postfire debris flows are typically runoff
generated. The U.S. Geological Survey has been studying the mechanisms of postfire debris-flow initiation for multiple decades to generate operational models for forecasting the timing, location, and magnitude of postfire debris flows. Here we discuss challenges and progress for extending operational
Authors
Katherine R. Barnhart, Ryan P Jones, David L. George, Francis K. Rengers, Jason W. Kean
Simulating debris flow and levee formation in the 2D shallow flow model D-Claw: Channelized and unconfined flow
Debris flow runout poses a hazard to life and infrastructure. The expansion of human population into mountainous areas and onto alluvial fans increases the need to predict and mitigate debris flow runout hazards. Debris flows on unconfined alluvial fans can exhibit spontaneous self-channelization through levee formation that reduces lateral spreading and extends runout distances compared to unchan
Authors
Ryan P. Jones, Francis K. Rengers, Katherine R. Barnhart, David L. George, Dennis M. Staley, Jason W. Kean
Insights on multistage rock avalanche behavior from runout modeling constrained by seismic inversions
Inversion of low-frequency regional seismic records to solve for a time series of bulk forces exerted on the earth by a landslide (a force-time function) is increasingly being used to infer volumes and dynamics of large, highly energetic landslides, such as rock avalanches and flowslides, and to provide calibration information on event dynamics and volumes for numerical landslide runout models. Mu
Authors
Andrew Mitchell, Kate E. Allstadt, David L. George, Jordan Aaron, Scott McDougall, Jeffrey R. Moore, Brian Menounous
Modeling the dynamics of lahars that originate as landslides on the west side of Mount Rainier, Washington
Large lahars pose substantial threats to people and property downstream from Mount Rainier volcano in Washington State. Geologic evidence indicates that these threats exist even during the absence of volcanic activity and that the threats are highest in the densely populated Puyallup and Nisqually River valleys on the west side of the volcano. However, the precise character of these threats can be
Authors
David L. George, Richard M. Iverson, Charles M. Cannon
Multi-model comparison of computed debris flow runout for the 9 January 2018 Montecito, California post-wildfire event
Hazard assessment for post-wildfire debris flows, which are common in the steep terrain of the western United States, has focused on the susceptibility of upstream basins to generate debris flows. However, reducing public exposure to this hazard also requires an assessment of hazards in downstream areas that might be inundated during debris flow runout. Debris flow runout models are widely availab
Authors
Katherine R. Barnhart, Ryan P. Jones, David L. George, Brian W. McArdell, Francis K. Rengers, Dennis M. Staley, Jason W. Kean
Preliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska
We simulated the concurrent rapid motion of landslides on an unstable slope at Barry Arm, Alaska. Movement of landslides into the adjacent fjord displaced fjord water and generated a tsunami, which propagated out of Barry Arm. Rather than assuming an initial sea surface height, velocity, and location for the tsunami, we generated the tsunami directly using a model capable of simulating the dynamic
Authors
Katherine R. Barnhart, Ryan P. Jones, David L. George, Jeffrey A. Coe, Dennis M. Staley
When hazard avoidance is not an option: Lessons learned from monitoring the postdisaster Oso landslide, USA
On 22 March 2014, a massive, catastrophic landslide occurred near Oso, Washington, USA, sweeping more than 1 km across the adjacent valley flats and killing 43 people. For the following 5 weeks, hundreds of workers engaged in an exhaustive search, rescue, and recovery effort directly in the landslide runout path. These workers could not avoid the risks posed by additional large-scale slope collaps
Authors
Mark E. Reid, Jonathan W. Godt, Richard G LaHusen, Stephen L Slaughter, Thomas C. Badger, Brian D. Collins, William Schulz, Rex L. Baum, Jeffrey A. Coe, Edwin L Harp, Kevin M. Schmidt, Richard M. Iverson, Joel B. Smith, Ralph Haugerud, David L. George
Diverse cataclysmic floods from Pleistocene glacial Lake Missoula
In late Wisconsin time, the Purcell Trench lobe of the Cordilleran ice sheet dammed the Clark Fork of the Columbia River in western Montana, creating glacial Lake Missoula. During part of this epoch, the Okanogan lobe also dammed the Columbia River downstream, creating glacial Lake Columbia in northeast Washington. Repeated failure of the Purcell Trench ice dam released glacial Lake Missoula, caus
Authors
Roger P. Denlinger, David L. George, Charles M. Cannon, Jim E. O'Connor, Richard B. Waitt
The Missoula and Bonneville floods—A review of ice-age megafloods in the Columbia River basin
The Channeled Scabland of eastern Washington State, USA, brought megafloods to the scientific forefront. A 30,000-km2 landscape of coulees and cataracts carved into the region’s loess-covered basalt attests to overwhelming volumes of energetic water. The scarred landscape, garnished by huge boulder bars and far-travelled ice-rafted erratics, spurred J Harlen Bretz’s vigorously disputed flood hypot
Authors
Jim E. O'Connor, Victor R. Baker, Richard B. Waitt, Larry N Smith, Charles M. Cannon, David L. George, Roger P. Denlinger
Clawpack: Building an open source ecosystem for solving hyperbolic PDEs
Clawpack is a software package designed to solve nonlinear hyperbolic partial differential equations using high-resolution finite volume methods based on Riemann solvers and limiters. The package includes a number of variants aimed at different applications and user communities. Clawpack has been actively developed as an open source project for over 20 years. The latest major release, Clawpack 5,
Authors
Kyle T. Mandli, Aron J. Ahmadia, Marsha J Berger, Donna A Calhoun, David L. George, Yiannis Hadjimichael, David I. Ketcheson, Grady I. Lemoine, Randall J. LeVeque
Overcoming barriers to progress in seismic monitoring and characterization of debris flows and lahars
Debris flows generate seismic signals that contain valuable information about events as they unfold. Though seismic waves have been used for along-channel debris-flow and lahar monitoring systems for decades, it has proven difficult to move beyond detection to more quantitative characterizations of flow parameters and event size. This is for two primary reasons: (1) our limited understanding of ho
Authors
Kate E. Allstadt, Maxime Farin, Andrew Lockhart, Sara McBride, Jason W. Kean, Richard M. Iverson, Matthew Logan, Joel B. Smith, Victor C. Tsai, David L. George
Seamless numerical simulation of a hazard cascade in which a landslide triggers a dam-breach flood and consequent debris flow
Numerical simulations of hazard cascades downstream from moraine-dammed lakes commonly must specify linkages between models of discrete processes such as wave overtopping, dam breaching, erosion, and downstream floods or debris flows. Such linkages can be rather arbitrary and can detract from the ability to accurately conserve mass and momentum during complex sequences of events. Here we describ
Authors
David L. George, Richard M. Iverson, Charles M. Cannon
Non-USGS Publications**
D. L. George, 2008: Augmented Riemann solvers for the shallow water equations over variable topography with steady states and inundation. J. Comput. Phys., 227(6): 3089--3113.
R. J. LeVeque and D. L. George, 2008: High-resolution finite volume methods for the shallow water equations with topography and dry-states. In P. L. Liu, C. Synolakis, and H. Yeh, editors, Advanced Numerical Models for Simulating Tsunami Waves and Runup, vol. 10 of Advances in Coastal and Ocean Engineering, pp. 43--73. World Scientific.
D. L. George and R. J. LeVeque, 2008: High-resolution methods and adaptive refinement for tsunami propagation and inundation. In S. Benzoni-Gavage and D. Serre, editors, Hyperbolic Problems: Theory, Numerics, Applications, pp. 541--549, Springer.
D. L. George and R. J. LeVeque, 2006: Finite volume methods and adaptive refinement for global tsunami propagation and inundation. Science of Tsunami Hazards, Vol. 24. No. 5, 319--328.
**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.
Simulated inundation extent and depth in Harriman Fjord and Barry Arm, western Prince William Sound, Alaska, resulting from the hypothetical rapid motion of landslides into Barry Arm Fjord, Prince William Sound, Alaska
Summary
This data release contains postprocessed model output from a simulation of hypothetical rapid motion of landslides, subsequent wave generation, and wave propagation. A simulated displacement wave was generated by rapid motion of unstable material into Barry Arm fjord. We consider the wave propagation in Harriman Fjord and Barry Arm, western Prince William Sound (area of interest and place
Simulated inundation extent and depth at Whittier, Alaska resulting from the hypothetical rapid motion of landslides into Barry Arm Fjord, Prince William Sound, Alaska
This data release contains postprocessed model output from simulations of hypothetical rapid motion of landslides, subsequent wave generation, and wave propagation. A modeled tsunami wave was generated by rapid motion of unstable material into Barry Arm Fjord. This wave propagated through Prince William Sound and then into Passage Canal east of Whittier. Here we consider only the largest wave-gene
Select model results from simulations of hypothetical rapid failures of landslides into Barry Arm, Prince William Sound, Alaska
This data release contains model output from simulations presented in the associated Open-File Report (Barnhart and others, 2021). In this report, we present model results from four simulations (scenarios C-290, NC-290, C-689, NC-689, Table 1) of hypothetical rapid movement of landslides into adjacent fjord water at Barry Arm, Alaska using the D-Claw model (George and Iverson, 2014; Iverson and Ge
Data to support modeling of the 2015 Tyndall Glacier landslide, Alaska
Landslide-generated tsunamis pose significant hazards, but developing models to assess these hazards presents unique challenges. George and others (2017) present a new methodology in which a depth-averaged two-phase landslide model (D-Claw) is used to simulate all stages of landslide dynamics and subsequent tsunami generation, propagation, and inundation. Because the model describes the evolution
digger: A python package for D-Claw model inputs
Digger is a python package that provides a number of pre- and post-processing tools for working with the D-Claw model.
Science and Products
- Publications
Filter Total Items: 28
Forecasting the inundation of postfire debris flows
In the semi-arid regions of the western United States, postfire debris flows are typically runoff generated. The U.S. Geological Survey has been studying the mechanisms of postfire debris-flow initiation for multiple decades to generate operational models for forecasting the timing, location, and magnitude of postfire debris flows. Here we discuss challenges and progress for extending operationalAuthorsKatherine R. Barnhart, Ryan P Jones, David L. George, Francis K. Rengers, Jason W. KeanSimulating debris flow and levee formation in the 2D shallow flow model D-Claw: Channelized and unconfined flow
Debris flow runout poses a hazard to life and infrastructure. The expansion of human population into mountainous areas and onto alluvial fans increases the need to predict and mitigate debris flow runout hazards. Debris flows on unconfined alluvial fans can exhibit spontaneous self-channelization through levee formation that reduces lateral spreading and extends runout distances compared to unchanAuthorsRyan P. Jones, Francis K. Rengers, Katherine R. Barnhart, David L. George, Dennis M. Staley, Jason W. KeanInsights on multistage rock avalanche behavior from runout modeling constrained by seismic inversions
Inversion of low-frequency regional seismic records to solve for a time series of bulk forces exerted on the earth by a landslide (a force-time function) is increasingly being used to infer volumes and dynamics of large, highly energetic landslides, such as rock avalanches and flowslides, and to provide calibration information on event dynamics and volumes for numerical landslide runout models. MuAuthorsAndrew Mitchell, Kate E. Allstadt, David L. George, Jordan Aaron, Scott McDougall, Jeffrey R. Moore, Brian MenounousModeling the dynamics of lahars that originate as landslides on the west side of Mount Rainier, Washington
Large lahars pose substantial threats to people and property downstream from Mount Rainier volcano in Washington State. Geologic evidence indicates that these threats exist even during the absence of volcanic activity and that the threats are highest in the densely populated Puyallup and Nisqually River valleys on the west side of the volcano. However, the precise character of these threats can beAuthorsDavid L. George, Richard M. Iverson, Charles M. CannonMulti-model comparison of computed debris flow runout for the 9 January 2018 Montecito, California post-wildfire event
Hazard assessment for post-wildfire debris flows, which are common in the steep terrain of the western United States, has focused on the susceptibility of upstream basins to generate debris flows. However, reducing public exposure to this hazard also requires an assessment of hazards in downstream areas that might be inundated during debris flow runout. Debris flow runout models are widely availabAuthorsKatherine R. Barnhart, Ryan P. Jones, David L. George, Brian W. McArdell, Francis K. Rengers, Dennis M. Staley, Jason W. KeanPreliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska
We simulated the concurrent rapid motion of landslides on an unstable slope at Barry Arm, Alaska. Movement of landslides into the adjacent fjord displaced fjord water and generated a tsunami, which propagated out of Barry Arm. Rather than assuming an initial sea surface height, velocity, and location for the tsunami, we generated the tsunami directly using a model capable of simulating the dynamicAuthorsKatherine R. Barnhart, Ryan P. Jones, David L. George, Jeffrey A. Coe, Dennis M. StaleyWhen hazard avoidance is not an option: Lessons learned from monitoring the postdisaster Oso landslide, USA
On 22 March 2014, a massive, catastrophic landslide occurred near Oso, Washington, USA, sweeping more than 1 km across the adjacent valley flats and killing 43 people. For the following 5 weeks, hundreds of workers engaged in an exhaustive search, rescue, and recovery effort directly in the landslide runout path. These workers could not avoid the risks posed by additional large-scale slope collapsAuthorsMark E. Reid, Jonathan W. Godt, Richard G LaHusen, Stephen L Slaughter, Thomas C. Badger, Brian D. Collins, William Schulz, Rex L. Baum, Jeffrey A. Coe, Edwin L Harp, Kevin M. Schmidt, Richard M. Iverson, Joel B. Smith, Ralph Haugerud, David L. GeorgeDiverse cataclysmic floods from Pleistocene glacial Lake Missoula
In late Wisconsin time, the Purcell Trench lobe of the Cordilleran ice sheet dammed the Clark Fork of the Columbia River in western Montana, creating glacial Lake Missoula. During part of this epoch, the Okanogan lobe also dammed the Columbia River downstream, creating glacial Lake Columbia in northeast Washington. Repeated failure of the Purcell Trench ice dam released glacial Lake Missoula, causAuthorsRoger P. Denlinger, David L. George, Charles M. Cannon, Jim E. O'Connor, Richard B. WaittThe Missoula and Bonneville floods—A review of ice-age megafloods in the Columbia River basin
The Channeled Scabland of eastern Washington State, USA, brought megafloods to the scientific forefront. A 30,000-km2 landscape of coulees and cataracts carved into the region’s loess-covered basalt attests to overwhelming volumes of energetic water. The scarred landscape, garnished by huge boulder bars and far-travelled ice-rafted erratics, spurred J Harlen Bretz’s vigorously disputed flood hypotAuthorsJim E. O'Connor, Victor R. Baker, Richard B. Waitt, Larry N Smith, Charles M. Cannon, David L. George, Roger P. DenlingerClawpack: Building an open source ecosystem for solving hyperbolic PDEs
Clawpack is a software package designed to solve nonlinear hyperbolic partial differential equations using high-resolution finite volume methods based on Riemann solvers and limiters. The package includes a number of variants aimed at different applications and user communities. Clawpack has been actively developed as an open source project for over 20 years. The latest major release, Clawpack 5,AuthorsKyle T. Mandli, Aron J. Ahmadia, Marsha J Berger, Donna A Calhoun, David L. George, Yiannis Hadjimichael, David I. Ketcheson, Grady I. Lemoine, Randall J. LeVequeOvercoming barriers to progress in seismic monitoring and characterization of debris flows and lahars
Debris flows generate seismic signals that contain valuable information about events as they unfold. Though seismic waves have been used for along-channel debris-flow and lahar monitoring systems for decades, it has proven difficult to move beyond detection to more quantitative characterizations of flow parameters and event size. This is for two primary reasons: (1) our limited understanding of hoAuthorsKate E. Allstadt, Maxime Farin, Andrew Lockhart, Sara McBride, Jason W. Kean, Richard M. Iverson, Matthew Logan, Joel B. Smith, Victor C. Tsai, David L. GeorgeSeamless numerical simulation of a hazard cascade in which a landslide triggers a dam-breach flood and consequent debris flow
Numerical simulations of hazard cascades downstream from moraine-dammed lakes commonly must specify linkages between models of discrete processes such as wave overtopping, dam breaching, erosion, and downstream floods or debris flows. Such linkages can be rather arbitrary and can detract from the ability to accurately conserve mass and momentum during complex sequences of events. Here we describAuthorsDavid L. George, Richard M. Iverson, Charles M. CannonNon-USGS Publications**
D. L. George, 2008: Augmented Riemann solvers for the shallow water equations over variable topography with steady states and inundation. J. Comput. Phys., 227(6): 3089--3113.R. J. LeVeque and D. L. George, 2008: High-resolution finite volume methods for the shallow water equations with topography and dry-states. In P. L. Liu, C. Synolakis, and H. Yeh, editors, Advanced Numerical Models for Simulating Tsunami Waves and Runup, vol. 10 of Advances in Coastal and Ocean Engineering, pp. 43--73. World Scientific.D. L. George and R. J. LeVeque, 2008: High-resolution methods and adaptive refinement for tsunami propagation and inundation. In S. Benzoni-Gavage and D. Serre, editors, Hyperbolic Problems: Theory, Numerics, Applications, pp. 541--549, Springer.D. L. George and R. J. LeVeque, 2006: Finite volume methods and adaptive refinement for global tsunami propagation and inundation. Science of Tsunami Hazards, Vol. 24. No. 5, 319--328.**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.
- Data
Simulated inundation extent and depth in Harriman Fjord and Barry Arm, western Prince William Sound, Alaska, resulting from the hypothetical rapid motion of landslides into Barry Arm Fjord, Prince William Sound, Alaska
Summary This data release contains postprocessed model output from a simulation of hypothetical rapid motion of landslides, subsequent wave generation, and wave propagation. A simulated displacement wave was generated by rapid motion of unstable material into Barry Arm fjord. We consider the wave propagation in Harriman Fjord and Barry Arm, western Prince William Sound (area of interest and placeSimulated inundation extent and depth at Whittier, Alaska resulting from the hypothetical rapid motion of landslides into Barry Arm Fjord, Prince William Sound, Alaska
This data release contains postprocessed model output from simulations of hypothetical rapid motion of landslides, subsequent wave generation, and wave propagation. A modeled tsunami wave was generated by rapid motion of unstable material into Barry Arm Fjord. This wave propagated through Prince William Sound and then into Passage Canal east of Whittier. Here we consider only the largest wave-geneSelect model results from simulations of hypothetical rapid failures of landslides into Barry Arm, Prince William Sound, Alaska
This data release contains model output from simulations presented in the associated Open-File Report (Barnhart and others, 2021). In this report, we present model results from four simulations (scenarios C-290, NC-290, C-689, NC-689, Table 1) of hypothetical rapid movement of landslides into adjacent fjord water at Barry Arm, Alaska using the D-Claw model (George and Iverson, 2014; Iverson and GeData to support modeling of the 2015 Tyndall Glacier landslide, Alaska
Landslide-generated tsunamis pose significant hazards, but developing models to assess these hazards presents unique challenges. George and others (2017) present a new methodology in which a depth-averaged two-phase landslide model (D-Claw) is used to simulate all stages of landslide dynamics and subsequent tsunami generation, propagation, and inundation. Because the model describes the evolution - Software
digger: A python package for D-Claw model inputs
Digger is a python package that provides a number of pre- and post-processing tools for working with the D-Claw model.