Publications
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Real-time monitoring of debris-flow velocity and mass deformation from field experiments with high sample rate lidar and video
Debris flows evolve in both time and space in complex ways, commonly starting as coherent failures but then quickly developing structures such as roll waves and surges. This process is readily observed, but difficult to study or quantify because of the speed at which it occurs. Many methods for studying debris flows consist of point measurements (e.g., of flow height or basal stresses), which are
Authors
Francis K. Rengers, Thomas Rapstine, Kate E. Allstadt, Michael Olsen, Michael Bunn, Richard M. Iverson, Jason W. Kean, Ben Leshchinsky, Matthew Logan, Mahyar Sharifi-Mood, Maciej Obryk, Joel B. Smith
Looking through the window of disturbance at post-wildfire debris-flow hazards
The extreme heat from wildfire alters soil properties and incinerates vegetation, leading to changes in infiltration capacity, ground cover, soil erodibility, and rainfall interception. These changes promote increases in runoff and sediment transport that increase the likelihood of runoff-generated debris flows. Over a period of several years, referred to as the window of disturbance, the landscap
Authors
Luke McGuire, Francis K. Rengers, Jason W. Kean, Dennis M. Staley, Hui Tang, Ann Youberg
Topographic change detection at Chalk Cliffs, Colorado, USA, using Airborne LiDAR and UAS-based Structure-from-Motion photogrammetry
The Chalk Cliffs debris-flow site is a small headwater catchment incised into highly fractured and hydrothermally altered quartz monzonite in a semi-arid climate. Over half of the extremely steep basin is exposed bedrock. Debris flows occur multiple times per year in response to rainstorm events, typically during the summer monsoon season. The frequency of debris flows, and the uniformity of the u
Authors
Katherine R Barnhart, Francis K. Rengers, Ghent Jessica N, Gregory E. Tucker, Jeffrey A. Coe, Jason W. Kean, Joel B. Smith, Dennis M. Staley, William Kleiber, Ashton M Wiens
Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc
Core samples from the International Ocean Discovery Program (IODP) Expedition 366 were tested in the laboratory to determine permeability, porosity, density, and frictional strength and their relation to mineralogy as part of an effort to understand hydro-mechanical processes at convergent plate margins. Seven samples were tested from a depth range of 19.6 to 197.9 m below the sea floor. The sampl
Authors
Carolyn A. Morrow, Diane E. Moore, David A. Lockner, Barbara A. Bekins
Changes in hydrodynamics and wave energy as a result of seagrass decline along the shoreline of a microtidal back-barrier estuary
Seagrasses are marine flowering plants that provide key ecological services. In recent decades, multiple stressors have caused a worldwide decline in seagrass beds. Changes in bottom friction associated with seagrass loss are expected to influence the ability of estuarine systems to trap sediment inputs through local and regional changes in hydrodynamics. Herein, we conduct a numerical study using
Authors
Carmine Donatelli, Neil Kamal Ganju, Tarandeep S. Kalra, S Fagherazzi, Nicoletta Leonardi
The roles of flow acceleration and deceleration in sediment suspension in the surf zone
Prediction of sediment suspension in the surf zone remains elusive. We explore how suspended sediment concentration at 19 cm above the bed in the mid-surf zone during a storm is influenced by flow acceleration and deceleration. There is a tendency for higher suspended sediment concentrations during onshore flow, with decelerating onshore flows having higher concentrations than steady, accelerating
Authors
Bruce E. Jaffe, SeanPaul La Selle
Post-fire rockfall and debris-flow hazard zonation in the Eagle Creek Fire burn area, Columbia River Gorge, Oregon: a tool for emergency managers and first responders
The Eagle Creek Fire engulfed 48,832 acres (196 km2) within the Columbia River Gorge, Oregon beginning September 2nd and was 100% contained by November 30th, 2017. The Columbia River Gorge area is steep and heavily forested characterized by cliffs and flanking talus slopes, receiving > 100 inches (> 254 cm) of precipitation annually. The Columbia River Gorge is a critical lifeline for Oregon and W
Authors
Nancy C. Calhoun, William J. Burns, S.H. Hayduk, Dennis M. Staley, Jason W. Kean
Taking the pulse of debris flows: Extracting debris-flow dynamics from good vibrations in southern California and central Colorado
The destructive nature of debris flows makes it difficult to quantify flow dynamics with direct instrumentation. For this reason, seismic sensors placed safely away from the flow path are often used to identify the timing and speed of debris flows. While seismic sensors have proven to be a valuable tool for event detection and early warning, their potential for identifying other aspects of debris
Authors
A. Michel, Jason W. Kean, Joel B. Smith, Kate E. Allstadt, Jeffrey A. Coe
Inundation, flow dynamics, and damage in the 9 January 2018 Montecito Debris-Flow Event, California, USA: Opportunities and challenges for post-wildfire risk assessment
Shortly before the beginning of the winter rainy season, one of the largest fires in California history (Thomas Fire) substantially increased the susceptibility of steep slopes in Santa Barbara and Ventura Counties to debris flows. On January 9, 2018, before the fire was fully contained, an intense burst of rain fell on the portion of the burn area above Montecito, CA. The rainfall and associated
Authors
Jason W. Kean, Dennis M. Staley, Jeremy T. Lancaster, Francis K. Rengers, Brian J. Swanson, Jeffrey A. Coe, Janis Hernandez, Aaron Sigman, Kate E. Allstadt, Donald N. Lindsay
Linking direct measurements of turbidity currents to submarine canyon-floor deposits
Submarine canyons are conduits for episodic and powerful sediment density flows (commonly called turbidity currents) that move globally significant amounts of terrestrial sediment and organic carbon into the deep sea, forming some of the largest sedimentary deposits on Earth. The only record available for most turbidity currents is the deposit they leave behind. Therefore, to understand turbidity
Authors
Katherine L. Maier, Jenny Gales, Charles K. Paull, Kurt J. Rosenberger, Peter J. Talling, Stephen Simmons, Roberto Gwiazda, Mary McGann, Matthieu J.B. Cartigny, Eve M. Lundsten, Krystle Anderson, Michael Clare, Jingping Xu, Daniel Parsons, James P. Barry, Monica Wolfson-Schwher, Nora M. Nieminski, Esther J. Sumner
The risk reduction benefits of the Mesoamerican Reef in Mexico
Coastal development and climate change are dramatically increasing the risks of flooding, erosion, and extreme weather events. Coral reefs and other coastal ecosystems act as natural defenses against coastal hazards, but their degradation increases risk to people and property. Environmental degradation, however, has rarely been quantified as a driver of coastal risk. In Quintana Roo, Mexico, a reg
Authors
Borja G. Reguero, Fernando Secaira, Alexandra Toimil, Mireille Escudero, Pedro Diaz-Simal, Michael W. Beck, Rodolfo Silva, Curt D. Storlazzi, Iñigo Losada
The influence of sea level on incident and infragravity wave-driven sediment dynamics across a fringing coral reef
Coral reefs generate significant volumes of carbonate sediment that becomes the primary source of beach material along many low-latitude shorelines that protect hundreds of millions of people globally. Despite this fact, there is little understanding of the specific processes that transport the carbonate sediment produced on the outer portions of coral reefs to the shoreline, let alone how those p
Authors
Curt D. Storlazzi, Olivia Cheriton, Kurt J. Rosenberger, Andrew Pomeroy, Ryan J. Lowe