Landslide Hazards Seminar
'Seismic and atmospheric acoustic waves reveal the dynamics of a large rock–ice avalanche in Denali National Park'
February 12, 2025
'When Rocks Heat Up: The Impact of Temperature on Rock Properties'
January 29, 2025
'Impacts of increasing precipitation variability on landslide triggering in the San Francisco Bay Area (California, USA) due to climate change'
January 15, 2025
'Feedbacks between river meandering and landsliding in northwestern Washington glacial outwash terraces'
July 10, 2024
'You'll never believe why the side of this mountain fell off!'
August 14, 2024
'California Geological Survey response to landsliding during the 2023 – 2024 winter storm season in California'
June 26, 2024
'The Mount Rainier Lahar Detection System: Risk mitigation for an unlikely, but potentially catastrophic, hazard'
May 15, 2024
The USGS Landslide Hazards Seminar is a speaker series that brings together landslide researchers, academics, students, applied scientists, and others to share their work in a long format. Topics range from deep dives into numerical models to broad overviews of landslide hazards of a state. The 50-minute presentations are presented live on regular Wednesdays at 2:00 PM Mountain Time.
2025 SEMINAR RECORDINGS
March 12, 2025, Paul Morgan, The University of Washington, Seattle
The damability function: A probabilistic approach to regional landslide dam susceptibility analysis applied to the Oregon Coast Range, USA
Landslides can dam rivers and require rapid response to mitigate catastrophic outburst floods. In this talk I will describe what landslide dams are including a few recent examples, and present a workflow to map landslide dam formation susceptibility at a regional scale. We define a probabilistic function that combines river valley width and landslide volume to efficiently determine the likelihood of a landslide dam or ‘damability’. We combine damability values with landslide susceptibility to find landslide dam susceptibility. We verify and apply our approach to the Oregon Coast Range, USA and find high susceptibility in river headwaters and generally steeper terrain, which in this case correlates with more resistant lithologies. We also estimate volumes of the potential dammed lakes and find that most rivers with high dam susceptibility are less likely to impound large lakes, because they have low drainage areas. However, widespread susceptibility, and the critical potential impacts from exceptionally large landslides, suggest this hazard should be considered in the Pacific Northwest. The damability function workflow can readily ingest new data and can be applied more broadly to assess future landslide dam hazards.
February 19, 2025, Yuankun Xu, University of California, Berkeley
Remote sensing and hydromechanical characterization of landslides
Yuankun Xu presents his research on landslides, focusing on how surface processes can be better understood using a combination of remote sensing, GPS, field instrumentation, and numerical modeling. His talk emphasizes the importance of integrating multiple methods to analyze landslide mechanics and hydrology, with specific case studies to demonstrate how surface movements correlate with subsurface hydromechanical processes.
February 12, 2025, Liam Toney, U.S. Geological Survey
Seismic and atmospheric acoustic waves reveal the dynamics of a large rock–ice avalanche in Denali National Park
In September 2023, a large rock–ice avalanche occurred in Denali National Park at Peters Dome, just 12 km from the summit of Denali. This landslide was well-recorded by Alaska’s robust geophysical sensor network, and it was reconnoitered by park staff on a fixed-wing flight the following day. In this talk, I’ll introduce seismology and infrasound (low-frequency atmospheric acoustics) as landslide monitoring tools. I’ll present the well-constrained Denali event as a showcase for the variety and quality of information we can rapidly and remotely obtain from these wiggles. I’ll conclude with some discussion of how seismology and infrasound might further contribute to future rapid landslide responses and ongoing monitoring efforts.
January 29, 2025, Jan Blahůt , Czech Academy of Sciences
When Rocks Heat Up: The Impact of Temperature on Rock Properties
This presentation discusses how temperature changes affect the properties of rocks and what that means for slope stability. It specifically looks at how wildfires in Czechia have altered rock properties. Additionally, it includes findings from research in Yosemite that investigates effects in a much cooler temperature range.
January 15, 2025, Colleen Murphy, U.S. Geological Survey
Impacts of increasing precipitation variability on landslide triggering in the San Francisco Bay Area (California, USA) due to climate change
Generation of sufficient soil pore-water pressure to trigger failure of rainfall-induced landslides depends on the combination of antecedent soil moisture and the intensity and duration of infiltrating rainfall during the triggering storm. Precipitation extremes and volatility are both projected to intensify in the future due to climate change, particularly in California (USA), which already experiences considerable interannual variability relative to the rest of the country as well as distinct seasonality. The effects of these changes on rainfall-induced landslides are not straightforward. Nominally, increasing precipitation intensities lead to more landslides, however above a certain threshold the efficacy will decrease as precipitation gets diverted from infiltration to runoff due to infiltration excess. Additionally, antecedent soil moisture conditions are likely to be affected by rising temperatures and changes in the timing and sequencing of storms relative to present. Here we explore the potential effects of these changes on landslide activity in the San Francisco Bay area using an ensemble of downscaled climate projections coupled to a 1-D hydrological model of transient, variably saturated flow in a 2-layer system. We first calibrate the model to site-specific groundwater observations and identify landslide days based on empirical hydrological thresholds. We then apply the model chain to historical and future (1950-2100) climate projections to assess changes in the characteristics and frequency of landslide triggering conditions due to the interplay of intensifying precipitation, rising temperatures, and changes in the frequency and timing of precipitation events. For shallow landslides, we project an increase in the frequency of both extreme landslide years and years with no landslide days at all, as well as a small increase the average annual number of landslide days overall.
2024 SEMINAR RECORDINGS
November 20, 2024, Maryn Sanders, University of Oregon, and David Sousa, Oregon State University
Controls on post-fire debris flows in Oregon
Wildfire often amplifies the likelihood and magnitude of debris flows in steep terrain. In arid climates (e.g. US Mountain West and Southwest), post-fire debris flows typically occur during the first rains following fire, suggesting that rainfall-driven erosion is a strong control on in-channel preconditioning and triggering of these hazards. However, in the humid and forested steeplands of the Pacific Northwest, there is an apparent lag between cessation of burning and debris flow occurrence that suggests controls differ from drier climates. Preliminary results suggest that post-fire debris flows in Western Oregon are associated with the delayed triggering of shallow landslides and in-channel bed failures years after burning. David and Maryn are working to evaluate the spatiotemporal controls on post-fire debris-flow initiation and their impact on transportation infrastructure. Their respective research focuses on the physical characterization of root strength following wildfire and quantification of fire-related debris flow erosion relative to the long-term evolution of the Columbia River Gorge, OR.
November 13, 2024, Jonathan King, U.S. Geological Survey
Building an operational framework for postfire debris-flow hazard assessments
Recently burned landscapes are often at elevated risk for debris-flows. To address this, the USGS releases over 50 postfire debris-flow hazard assessments each year, and these assessments are used by stakeholders, emergency managers, and the public to inform postfire response. In this talk, we will discuss recent efforts to modernize the operational framework for producing these assessments. Previously, the USGS relied on a collection of research codes, but these were not open source, were prone to breaking, and struggled to handle assessments for large fires. In the last year, we have converted these research codes to a collection of open-source software tools designed for a variety of users and use cases. These include the “pfdf” Python library, the “wildcat” assessment tool, and the USGS’s in-house operational codebase. We’ll provide a brief introduction to each of these tools, and then discuss future planned developments for the operational framework.
October 9, 2024, Chuxuan Li, UCLA
Use of WRF-Hydro to identify landslide-susceptible areas at regional scales
Landslide-triggering weather systems often operate on expansive spatial scales, causing widespread landsliding activity. Diverse landslide-conditioning factors, such as wildfires, antecedent soil moisture, and snowpack, within these weather systems' extensive footprints, along with complex dynamic interactions, make regional landslide susceptibility prediction increasingly challenging and in need of multidisciplinary approaches. Here, I argue that regional hydrometeorology, which integrates atmospheric, hydrologic, and geomorphic processes, is key to advancing large-scale landslide susceptibility prediction. This presentation introduces a methodological framework for identifying landslide-prone areas at regional scales using physics-based hydrological simulations from WRF-Hydro. It begins by demonstrating WRF-Hydro's ability to simulate landslide-relevant variables, such as soil moisture and streamflow, over a regional domain in California. Next, it presents a case study on numerous postfire debris flows triggered by an atmospheric river along the central Californian coast. Lastly, a case study on widespread landsliding activity caused by the parade of nine atmospheric rivers during the 2022-2023 winter season in California will be presented.
September 18, 2024, Bill Burns, Oregon Department of Geology and Mineral Industry
Using multitemporal lidar to better understand landslide and debris-flow hazards in western Oregon
In 2017, the Eagle Creek fire scorched the western portion of the Oregon side of the Columbia Rive Gorge (CRG). In 2021 and 2022 atmospheric river type storms triggered many post-fire debris flows. The purpose of this research/paper is to evaluate pre- and post-2017 Eagle Creek Fire debris flows in the WCRG (western Columbia River Gorge) study area using multi-temporal bare earth lidar digital elevation model. To understand the difference between pre-fire debris flows and post-fire debris flows in the WCRG, multiple sources of data were collected and analyzed. The primary data sets were field data collected after storms, orthophotos, and the multitemporal lidar data sets used to map the debris flows.
August 21, 2024, Jonathan Perkins, U.S. Geological Survey
Characterizing the scale of regional landslide triggering in California from storm hydrometeorology
Landslides are a global issue that results in deaths and economic losses annually. However, it is not clear how storm severity relates to landslide severity across large regions. Here we develop a method to estimate the footprint of landslide area and compare this to meteorologic estimates of storm severity. We find that total storm strength does not clearly relate to landslide area. Rather, landslide area depends on soil wetness and smaller storm structures that can produce intense rainfall.
August 14, 2024, Philip Prince, Appalachian Landslide Consultants
Blockslides, summit grabens, and collapsing highwalls of the Appalachian Valley and Ridge: Using lidar-derived imagery to reevaluate a thoroughly studied landscape
In the mid-1980s, Art Schultz (USGS, ret.) drew on experiences in the Colorado Front Range to identify numerous large, stratigraphically intact, kilometer-scale bedrock landslides on interbedded sandstone-shale dip slopes in the Virginia Valley and Ridge. The physical scale of the slides, along with the thick forest cover, made slide identification challenging, as slides could easily be mistaken for compressional fold-thrust features detached in shale horizons. As a result, the distribution and extent of blocksliding could not be fully evaluated at the time. Revisiting Valley and Ridge slopes with newly available 1-meter lidar datasets highlights the ubiquity of dip slope failure in the central and southern Appalachian Valley and Ridge, with many slides showing morphological features that imply relative youth. In addition to translational blockslides, lidar-derived imagery reveals numerous sackungen in rugged topography developed on gently dipping, interbedded sandstone-shale ridges. Abandoned late 19th and early 20th century iron mines on intact slopes in the vicinity of large blockslides show deep-seated slope movement almost certainly related to mine excavations. The extent of these movements relative to excavation size suggests that caprock-supported rugged topography in the Valley and Ridge may exist at or near the mechanical limit of weaker strata interbedded within the caprock interval. Lidar-supported investigation of Valley and Ridge bedrock slope movements invites reflection on the interpretive skill of Schultz and collaborators and a reconsideration of how potential slope behavior may impact infrastructure in the region..
July 24, 2024, Brittany Selander, U.S. Geological Survey
Impacts of wildfire on debris-flow hazards in Oregon’s western Cascade Range
In the steep and mountainous environment of western Oregon, debris flows pose a significant threat to property, infrastructure, and life. Wildfire increases the susceptibility of steep slopes to debris flow. The USGS estimates postfire debris-flow likelihood and triggering rainfall thresholds using the M1 postfire debris-flow likelihood model. This model was calibrated with data from southern California, where postfire debris flows typically initiate from distributed runoff and erosion. Due to a lack of available data, the likelihood model has not been tested in western Oregon, or in locations where postfire debris flows initiate via other mechanisms (e.g., shallow landslides or in-channel failures). Using repeat field observations and aerial imagery, we developed two new debris-flow inventories within, and adjacent to, the perimeters of five 2020 wildfires in western Oregon: Archie Creek, Holiday Farm, Beachie Creek, Lionshead, and Riverside. The first inventory focuses on debris flows prior to fires (1995-2020); the second focuses on postfire debris flows (2020-2022). Using these pre- and postfire inventories, we investigate how wildfire alters the initiation and frequency of debris flows. We additionally test the performance of the postfire debris-flow likelihood model. In this talk will summarize what we have learned about postfire debris-flow hazards in Oregon's western Cascade Range.
July 17, 2024, Matthew Morriss, Utah Geological Survey
Insights from the Chaos Canyon landslide, Rocky Mountain National Park
This study investigates the Chaos Canyon landslide that occurred on June 28, 2022, in Rocky Mountain National Park. Wes ought to understand the factors contributing to alpine instabilities in a changing climate. Using satellite data, field observations, and climate analysis, we examined the landslide's movement history, volume, and potential causes. A mix of empirical and model based evidence suggests that permafrost thaw, weakened basal shear zone, and increased pore-fluid pressure from snowmelt led to the collapse. The researchers estimate the volume of displaced material and discuss the implications for future alpine topography in warming climates. Through detailed mapping and SfM models we estimate that ∼1 258 000 ± 150 000 m^3 of material was deposited at the slide toe and ∼1 340 000 ± 133 000 m^3 of material was evacuated from the source area. In a warming climate, landslides like this may be representative of future dynamic alpine topography.
July 10, 2024, Shelby Ahrendt, U.S. Geological Survey
Feedbacks between river meandering and landsliding in northwestern Washington glacial outwash terraces
Landslides that occur in river valleys can be large, highly mobile, and cause cascading downstream hazards associated with landslide dams and elevated flood risk. However, the role of rivers in triggering landslides is not well understood: are there spatial and temporal patterns in river geometry leading up to major landslide events? Additionally, how does river geometry respond to deep-seated landsliding?
This talk investigates river-landslide feedbacks in the Nooksack River in western Washington State where the channel is flanked by landslide-prone glacial terraces that are similar to those that failed in the deadly 2014 Oso landslide. We show that landsliding and river meandering can be dynamically coupled: deep-seated landslides can “push” the river away from the floodplain margin, creating a new up- or downstream river meander. This new meander erodes the adjacent terrace, triggering a secondary landslide. This conceptual model has ramifications for improving hazard management in river corridors as well as informing fundamental understandings of the river-hillslope interface in landscape evolution..
June 26, 2024, Paul Burgess, California Geological Survey
CGS response to landsliding during the 2023 – 2024 winter storm season in California
From mid November 2023 until late March 2024, sixteen atmospheric river events impacted California, resulting in water year-to-date precipitation accumulations varying from more than 200 to 300% above average across selected areas of the state. Similar to the 2022 – 2023 winter storm season, California experienced historic flooding and multi-modal landslide activity that damaged transportation infrastructure, homes, property, and threatened life-safety and economic welfare across the state. California Geological Survey (CGS) staff worked to provide situational awareness of statewide landslide hazards to the State Geologist through partnership with various government and community sources. CGS leveraged its Reported Landslides Database (RLD) mapping tools for desktop and field surveying to rapidly identify areas of observed landslide impacts. The RLD mapping team identified more than 600 landslides, resulting in deployment of field teams to provide further assistance to hardest hit areas. CGS utilized these data to guide ongoing support of partner agency response to landslide hazards statewide.
This talk will explore how the RLD can be applied as a tool before during and after landslide response work, and also highlight some particularly notable landslide events that occurred in California this past winter.
June 12, 2024, Ben Mirus, U.S. Geological Survey
Parsimonious landslide susceptibility modeling at continental scales: a new high-resolution national landslides map
Landslide susceptibility maps are a fundamental tool for risk reduction. We used the USGS's landslide inventory compilation (N=613,724), high-resolution 3DEP digital elevation model (~10-m), and high-performance computing resources (YETI), to develop a new nation-wide susceptibility map for the Continental U.S., Hawaii, Alaska, and Puerto Rico. We used a parsimonious slope-relief threshold approach to distinguish between areas with some landslide potential from those with none, then down-sample our results to a 90-meter grid to account for uncertainty in the DEM, landslide position, and other factors. In addition to our rigorous 70/30 split-sample calibration and evaluation with multiple iterations, an independent validation with four statewide inventories (N=172,367) further reinforces the robustness of our threshold model, but also highlights spatially variable performance. Therefore, we propose a novel approach to susceptibility classification using the concentration of landslide-prone terrain within each down-sampled grid. While landslides are possible within any cells containing susceptible terrain, those with the highest concentration capture the majority of landslides. Our new map is more accurate than prior models; it also provides a transparent and flexible approach to susceptibility classification for implementing different tolerances for landslide risk reduction.
May 15, 2024, Seth Moran, U.S. Geological Survey
The Mount Rainier Lahar Detection System: Risk mitigation for an unlikely, but potentially catastrophic, hazard
Of all the volcanic hazards associated with Mount Rainier, large lahars pose the greatest risk to communities downstream of the volcano—more than 90,000 people live in areas that could be impacted by a future large lahar. Most lahars have been associated with eruptions except for the ~1507 A.D. landslide-initiated Electron Mudflow, for which no evidence of an associated eruption has been found. Recent studies show that the western flank of Mount Rainier could produce future non-eruptive landslides and associated large lahars down the Puyallup and/or Tahoma Creek drainages, potentially reaching nearby small towns within 5-10 minutes and larger communities within 60 minutes.
The Mount Rainier Lahar Detection System (RLDS) is part of a risk-mitigation strategy pursued by a group of local, State, and Federal agencies since 1998. It consists of several components: 1) a real-time network of tens of seismometers, infrasound arrays, tripwires, webcams, and other instruments located on the flanks of the volcano and along vulnerable drainages operated and upgraded periodically by the U.S. Geological Survey (USGS) Cascades Volcano Observatory (CVO) and the Pacific Northwest Seismic Network; 2) an automated detection system, designed and maintained by CVO, that triggers alarms in two separate county- and State-run 24/7 emergency operations centers; and 3) a set of protocols and inter-agency agreements among CVO, Pierce County (Washington) Department of Emergency Management, and the Washington State Emergency Management Division that delineate each agency’s detection, alerting, and/or warning responsibilities, protocols that are reviewed and tested periodically.
This presentation will give a broad overview of the history and current status of the RLDS, including some of the challenges we have faced in achieving operational objectives.
May 8, 2024, Drake Singleton, U.S. Geological Survey
Submarine slope failures associated with the 1964 M9.2 Great Alaska Earthquake in the fjords of southcentral Alaska
The March 27, 1964, Mw 9.2 Great Alaska Earthquake produced strong ground motions across coastal southcentral Alaska. In the fjords of Prince William Sound (PWS), which overlie the 1964 epicenter and rupture area, intense shaking generated widespread destabilization and failure of submerged fjord sediments. Some of these slope failures in turn generated devastating tsunamis that impacted several coastal communities. While sediments in some fjords failed in 1964, others did not, suggesting that a complex interplay between basin physiography, sediment accumulation, and shaking intensity determines the degree of instability that develops within each local fjord depositional system. This talk will highlight observations from a dataset of high-resolution Chirp sub-bottom profiles and shallow gravity cores recently collected across the fjords of southcentral Alaska. Using this dataset, we investigate factors that contributed to observed variations in the 1964 deposit character with the goal of quantifying the relationships between seismic parameters (i.e., shaking intensity), the sedimentary response (i.e., total volume remobilized and thickness of the resulting deposit), and the potential for a particular slide to generate a tsunami.
April 24, 2024, Catherine Pennington and Roxanne Ciurean, British Geological Survey
Stability in motion: an overview of interdisciplinary landslide research at the British Geological Survey
Overview of landslide research at the British Geological Survey.
April 10, 2024, Pukar Amatya, U.S. Geological Survey
Accuracy assessment of rapid response landslide maps generated using open-source tools during the August 2021 Haiti earthquake
A singular heavy rainfall event or earthquake can trigger hundreds to thousands of landslides. The first and most important information that on-the-ground disaster responders need following a major landslide event is information on the location and extent of landslides. Typically, the most used method for rapid landslide identification is manual mapping, a technique that is limiting in space and time. Recent availability of very high-resolution optical imagery and advancement in image processing technologies have significantly improved our ability to map landslides automatically. On August 14, 2021, a Mw 7.2 earthquake struck the Tiburon Peninsula of western Haiti triggering thousands of landslides. Three days after the earthquake on August 17, 2021, Tropical Storm Grace crossed shallow waters offshore of southern Haiti triggering more landslides worsening the situation. In the aftermath of these events, several organizations with disaster response capabilities or programs activated to provide information on the location of landslides to first responders on the ground. The 2021 Haiti event provided a unique opportunity to test different automated landslide detection methods that utilized both SAR and optical data in a rapid response scenario where rapid situational awareness was critical. As the methods used are highly replicable, I will be presenting on the landslide rapid response products released by the organizations, detection methods, accuracy quantification and guidelines on how some of the shortcomings encountered in this effort might be addressed in the future.
March 20, 2024, Sabrina Martinez, U.S. Geological Survey
Variations in population exposure to landslides within the United States
The 2021 National Landslide Preparedness Act directs the United States Department of the Interior to identify and understand hazards and societal risks posed by landslides across the country. However, a consistent and nationwide understanding of the societal risk posed by landslides does not exist. We attempt to fill this gap by characterizing exposure to landslides across the country using gridded 90-meter resolution landslide susceptibility and population models. The susceptibility model describes where landslides are more and less likely to occur. The LandScan USA population models estimate the number of people in a particular area. Results reveal regional variations in population exposure, such as the disparity in both the total number of people and the proportion of populations exposed to landsliding in different regions. In California, for example, a high number of people are exposed to landslides (> 8 million), but this number comprises only a small proportion of the total population of the entire state (< 30%). In contrast, in West Virginia and Puerto Rico, a low number of people are exposed (< 2 million each), but the proportion of people exposed within the state and territory is relatively high (> 60% and 45% respectively). This example illustrates the utility of a consistent and nationwide understanding of landslide exposure. Decision makers, for example, can use exposure information to inform resource allocation for landslide risk-reduction efforts (e.g., targeted risk communication). Additionally, the information can guide more detailed geologic and demographic investigations in regions where significant societal impacts from landslide events are likely.
March 13, 2024, Lisa Luna, U.S. Geological Survey
Global rainfall thresholds for urban landslides
By 2050, 68% of people are projected to live in urban areas. As cities grow into steeper terrain, residents are increasingly exposed to hazards like rainfall-triggered landslides. Landslide early warning systems can help reduce this risk, but so far, few cities have established such systems. One barrier to doing so is lack of sufficient landslide inventory data to estimate rainfall thresholds for warning. In this talk, I will describe our efforts to estimate a global rainfall threshold for urban landslides and to learn how variable rainfall thresholds are between cities. Using a multi-level regression model and a new compilation of thousands of urban landslides reported in cities worldwide, we find that landslides were triggered under surprisingly similar rainfall conditions in most cities, despite contrasting environmental and economic characteristics. Furthermore, we show that one-third of landslides occurred during moderate storms, not only during extreme rainfall, and that urban landslides occurred at lower rainfall intensities than previously proposed global thresholds. Our results suggest that regional landslide early warning systems should consider differences between rural and urban areas and that cities with limited landslide inventory data may be able to use thresholds from other cities to inform warning efforts.
February 14, 2024, Sara Vallejo-Bernal, University of Potsdam
Atmospheric rivers cause the majority of precipitation-induced landslides in Western North America
By 2050, 68% of people are projected to live in urban areas. As cities grow into steeper terrain, residents are increasingly exposed to hazards like rainfall-triggered landslides. Landslide early warning systems can help reduce this risk, but so far, few cities have established such systems. One barrier to doing so is lack of sufficient landslide inventory data to estimate rainfall thresholds for warning. In this talk, I will describe our efforts to estimate a global rainfall threshold for urban landslides and to learn how variable rainfall thresholds are between cities. Using a multi-level regression model and a new compilation of thousands of urban landslides reported in cities worldwide, we find that landslides were triggered under surprisingly similar rainfall conditions in most cities, despite contrasting environmental and economic characteristics. Furthermore, we show that one-third of landslides occurred during moderate storms, not only during extreme rainfall, and that urban landslides occurred at lower rainfall intensities than previously proposed global thresholds. Our results suggest that regional landslide early warning systems should consider differences between rural and urban areas and that cities with limited landslide inventory data may be able to use thresholds from other cities to inform warning efforts.
February 21, 2024, Matt Thomas, U.S. Geological Survey and Nina Oakley, California Geological Survey
Rainfall intensification amplifies exposure of American Southwest to conditions that trigger postfire debris flows
Short-duration, high-intensity rainfall can initiate deadly and destructive debris flows after wildfire. Methods to estimate the conditions that can trigger debris flows exist and guidance to determine how often those thresholds will be exceeded under the present climate are available. However, the limited spatiotemporal resolution of climate models has hampered efforts to characterize how rainfall intensification driven by global warming may affect debris-flow hazard. We use dynamically downscaled (3.75-kilometer), convection-permitting simulations of short-duration (15-minute) rainfall to evaluate threshold exceedance for late 21st-century climate scenarios in the American Southwest. We observe significant increases in the frequency and magnitude of exceedances for regions dominated by cool- and warm-season rainfall. We also observe an increased frequency of exceedance in regions where postfire debris flows have not been documented and communities are unaccustomed to the hazard. Our findings can inform planning efforts to increase resiliency to debris flows under a changing climate.
January 17, 2024, Kate Allstadt, U.S. Geological Survey
The Many Mysteries of the 2022 Chaos Canyon landslide in Rocky Mountain National Park
On 28 June 2022, ~2 million m3 of ice-rich debris mobilized from the southeast flank of Hallett Peak in Rocky Mountain National Park. The material slid rapidly for about 245 m into Chaos Canyon, a popular bouldering destination, stopping as it reached a relict rock glacier composed of massive boulders that fills the valley floor. Several climbers were bouldering near the toe of the landslide when it occurred. The group narrowly escaped and caught parts of the event on video, resulting in substantial nationwide media coverage. In this talk, I will detail a multifacted investigation in which we used eyewitness accounts, field and remote sensing techniques, historic climate data, and seismic recordings to unravel the mysteries of this unusual landslide and the events leading up to it. Direct observations of melting blocks of icy debris in the landslide deposits coupled with decades of slope deformation patterns correlated with warming temperatures strongly suggest permafrost degradation was the likely culprit. The main failure sequence itself was also relatively complex, with deformation starting earlier in the day and culminating in 3 energetic episodes of sliding. The slower deformation of the first energetic episode transitioned suddenly into the main and most energetic sliding episode immediately following a distant (~36 km) M1.4-equivalent reservoir construction blast. This raises interesting questions of whether the blast was a “red herring” or whether the very minor levels of shaking could have influenced the behavior of a marginally unstable landslide already in motion.
January 10, 2024, Alex Strouth, BGC Engineering
Landslide risk evaluation: tools and tips for risky decisions
When a landslide is recognized to be life-threatening, difficult decisions follow. Like, should the house be evacuated? Is the community safe enough? How much should be invested in mitigation? For the past two decades, we have been applying a quantitative risk management framework to inform these types of decisions. We’ve learned that landslide risk management requires practitioners to navigate through many options, nuances, and pitfalls, as they seek to balance competing (and often contradictory) objectives. This presentation will provide an overview of what we have learned along the way, including tools, tips, and lessons related to each of the three aspects that are balanced in a landslide risk evaluation: the risk estimate, perceptions of tolerable risk, and options for risk control.
2023 Seminars
2022 Seminars
2021 Seminars
| DATE | SPEAKER | AFFILIATION | TITLE (click to view video) |
|---|---|---|---|
| 12/08/2021 | Jennifer Bauer | Appalachian Landslide Consultants | Landslide science - One consultant’s role in connecting research with the public |
| 11/17/2021 | Jeremy Lancaster | California Geological Survey | Landslide case studies across California’s diverse terrain |
| 11/10/2021 | Annette Patton | University of Oregon | Climate change and landslides in subpolar Alaska: Less ice, more water |
| 10/27/2021 | Greg Stock | U.S. National Park Service | Pace of rockfalls and cliff retreat in Yosemite Valley since the Last Glacial Maximum |
| 10/20/2021 | Andrew Graber | Colorado School of Mines | Evaluating rockfall frequency from natural slopes at multiple timescales using multiple timescales – Examples fro Glenwood Canyon, CO |
| 9/29/2021 | Denny Capps | U.S. National Park Service | Infrastructure on ice – when your road rides on an accelerating rock glacier |
| 09/22/2021 | Erich Peitzcsh | U.S. Geological Survey | Snow avalanches: A hazard and driver of landscape change |
| 09/15/2021 | Paul Santi | Colorado School of Mines | Water and sediment supply requirements for post-wildfire debris flows in the western United States |
| 09/08/2021 | Richard Giraud | Utah Geological Survey | Utah landslides — Types, problems, and risk reduction |
| 08/25/2021 | Kevin Schmidt | U.S. Geological Survey | Active landsliding and rock strength controls along the Big Sur Coast, California |
| 08/18/2021 | Francis Ashland | U.S. Geological Survey | Widespread landslides during the 2018 wet year in Pittsburgh: The impact of extreme winter storms on subsurface hydrologic conditions and the resulting reduction of the critical rainfall threshold |
| 08/11/2021 | Helen Delano | Pennsylvania Geological Survey | Pennsylvania landslides, Pittsburgh and beyond: A 40-year perspective |
| 07/28/2021 | Kirk Townsend | University of Michigan | The contribution of rock-mass strength to topographic form and post-wildfire erosion: Insights from the western Transverse Ranges, southern California |
| 07/21/2021 | Kate Mickelson | Washington Geological Survey | Washington Geological Survey’s Landslide Hazard Program |
| 07/14/2021 | Katy Barnhart | U.S. Geological Survey | Preliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska |
| 06/30/2021 | Jon Perkins | U.S. Geological Survey | How can vadose zone hydrology influence the timing and dynamic range of seasonal landslide deformation? A case study from northern California’s Oak Ridge earthflow |
| 06/23/2021 | Matt Thomas | U.S. Geological Survey | Postwildfire soil-hydraulic recovery and the persistence of debris flow hazards |
| 06/16/2021 | Bill Burns | Oregon Dept. of Geology & Mineral Industries | Fire and debris-flow hazards in Oregon: ETART (BAER) and GEER - Initial post-fire debris flow observations |
| 06/09/2021 | Corey Froese | BGC Engineering | Management of large rock slope hazards: Two decades of learnings |
| 05/26/2021 | Jason Kean | U.S. Geological Survey | Forecasting the frequency and magnitude of postfire debris flows across southern California...and maybe beyond |
| 05/12/2021 | Scott McCoy | University of Nevada Reno | Rainfall-intensity thresholds for post-wildfire debris-flow initiation vary with climatology of peak rainfall intensity |
| 04/28/2021 | Adam Booth | Portland State University | Landslide-forest feedbacks in the United States' largest forest carbon reservoir: southeast Alaska |
| 04/21/2021 | Noah Finnegan | University of California Santa Cruz | Deformational processes governing frictional sliding in a large, slow-moving landslide |
| 04/14/2021 | James Guilinger | University of California Riverside | A nested scale analysis of postfire sediment source and transport dynamics across the 2018 Holy Fire burn scar, Santa Ana Mountains, CA |
| 03/31/2021 | Ingrid Tomac | University of California San Diego | Rainwater droplet impact dynamics on hydrophobic sand surface and mudflow onset mechanism |
| 03/24/2021 | Jeff Moore | University of Utah | Slope stability vibrometry: In-situ seismic vibration measurements for slope stability characterization and monitoring |
| 03/17/2021 | Stephanie Kampf | Colorado State University Fort Collins | Post-fire erosion model comparisons at hillslope to watershed scale |
| 03/10/2021 | Richard Iverson | U.S. Geological Survey | Landslide disparities, flume discoveries, and Oso despair |
| 02/24/2021 | Katy Barnhart, Ryan Jones, Matt Thomas | U.S. Geological Survey | Meet the Mendenhalls |
| 02/17/2021 | Netra Regmi | Oklahoma Geological Survey | Characteristics of shallow landslides in eastern Oklahoma and western Arkansas |
| 02/10/2021 | Jonathan Warrick | U.S. Geological Survey | Coastal landslides (and other changes) through the lens of SfM photogrammetry |
| 01/27/2021 | Alex Handwerger | University of California Los Angeles, Jet Propulsion Laboratory | Landslide identification using synthetic aperture radar change detection on the Google Earth Engine |
| 01/20/2021 | Kate Allstadt | U.S. Geological Survey | Documenting and modeling landslides and liquefaction triggered by recent US earthquakes |
| 01/13/2021 | Melissa Ward Jones | University of Alaska Fairbanks | Recent retrogressive thaw slumping activity in the Canadian high Arctic |
2020 Seminars
| 11/18/2020 | Colton Conroy | Columbia University | Modeling entrainment of bed sediment by debris flows and water floods |
| 10/28/2020 | Jeff Prancevic | U.S. Geological Survey | The relative importance of landslides and soil creep for eroding steep soil-mantled hillslopes |
| 10/21/2020 | Luke McGuire, Ann Youberg | University of Arizona, Arizona Geological Survey | Post-wildfire debris flow hazards: Insights from recovering burned areas in the Southwestern US |
| 10/14/2020 | Sean LaHusen | U.S. Geological Survey | Deep-seated landslide susceptibility and triggering in the Oregon Coast Range |
| 09/30/2020 | Benjamin Campforts | University of Colorado Boulder | How landslides alter sediment dynamics: Answers from HyLands, a large-scale landscape evolution model |
| 09/23/2020 | Margaret Darrow | University of Alaska Fairbanks | Impacts of permafrost slope stability on infrastructure in Arctic Alaska |
| 09/16/2020 | Matt Crawford | Kentucky Geological Survey | Landslide susceptibility and risk in eastern Kentucky |
| 09/09/2020 | William Medwedeff | University of Michigan | What controls weathering and hillslope strength in a tectonically active environment? Lessons from geotechnical observations in central Nepal |
| 08/26/2020 | Don Lindsay | California Geological Survey | A systematic approach to evaluating and prescribing post-fire triggering thresholds in the second year after wildfire |
| 08/19/2020 | Ben Mirus | U.S. Geological Survey | Landslides across the United States: Occurrence, susceptibility, and data limitations |
| 08/12/2020 | Hig Brentwood | Ground Truth Trekking | Questions raised by the Barry Arm landslides in Alaska |
| 07/29/2020 | Nina Oakley | Center for Western Weather & Water Extremes | Extreme precipitation research and tools at the Center for Western Weather and Water Extremes (CW3E) |
| 07/22/2020 | Corey Scheip | North Carolina State University | HazMapper: A global open-source natural hazard mapping application in Google Earth Engine |
| 07/15/2020 | Thomas Rapstine | U.S. Geological Survey | Towards airborne measurements of ground displacement |
| 07/08/2020 | Erin Bessette- Kirton | University of Utah | Slope stability vibration monitoring at Courthouse Mesa, Utah |
| 06/24/2020 | Arnaud Temme | Kansas State University | How do past landslides matter? |
| 06/17/2020 | Paul Burgess | California Geological Survey | Soil slip, shallow landslide, and debris flow activity in San Diego County, early April, 2020 |
| 06/10/2020 | Sabrina Martinez, Liam Toney | U.S. Geological Survey | Semi-automatic landslide detection in Puerto Rico and rock-ice avalanche dynamics in Alaska |
| 06/03/2020 | Eli Orland | National Aeronautics and Space Administration | Deep Learning to forecast soil moisture conditions on landslide-prone hillslopes |
| 05/20/2020 | Dalia Kirschbaum | National Aeronautics and Space Administration | Remote sensing of landslide hazard: A multi-scale, multi- modal approach |
| 05/13/2020 | Bill Schulz, Kenneth Hughes | U.S. Geological Survey, University of Puerto Rico Mayagüez | Factors contributing to hurricane-induced landslides in Puerto Rico: Implications for hazards and sediment mobilization |
| 05/06/2020 | Stephen Slaughter, Jeff Coe | U.S. Geological Survey | USGS landslide mission to Chile: Initial motivations, March 2020 travel log, and future plans |
| 04/22/2020 | Brian Collins | U.S. Geological Survey | Linking mesoscale meteorology with extreme landscape response |
| 04/15/2020 | Francis Ashland, Sabrina Martinez | U.S. Geological Survey | Landslide response efforts in Vicksburg, Mississippi |
| 04/08/2020 | Francis Rengers | U.S. Geological Survey | Controls on debris-flow initiation during an exceptional rainstorm in southern New Mexico |
| 04/01/2020 | Jaime Kostelnik | U.S. Geological Survey | Developing a post-wildfire debris-flow event database and web page |
| 03/11/2020 | Bill Schulz | U.S. Geological Survey | Using a dense seismic array to determine structure and site effects of the Two Towers Earthflow in northern California |
| 02/19/2020 | Lauren Schaefer | Colorado School of Mines | Estimating physical and mechanical rock properties through reflectance spectroscopy |