Technical Program

AEG 2020 Virtual Annual Meeting Technical Program






 Sponsored By AEG Gannett Fleming

Crossing the San Andreas Fault: Improving the Resilience of the Los Angeles Aqueduct System

2019-2020 Jahns Distinguished Lecturer – Scott Lindvall

Scott received his BS in Geology from Stanford University in 1984 and his MS in Geology from San Diego State University in 1988. Dick Jahns was Scott’s undergraduate advisor at Stanford, which makes this award especially meaningful to him. He has spent the majority of his career working for consulting firms specializing in seismic hazards and engineering geology. He currently manages the Lettis Consultants International southern California office.


Scott will present his “Crossing the San Andreas Fault: Improving the Resilience of the Los Angeles Aqueduct System” lecture at the meeting. This talk focuses on the Los Angeles Aqueduct crossing of the San Andreas fault in the Elizabeth Tunnel and describes the detailed surface and subsurface geologic investigations used to characterize the architecture of the fault zone at tunnel depth. Historic fault displacement data from global strike-slip faults are presented along with deterministic and probabilistic fault displacement hazard analyses performed to address the new 2019 performance-based seismic design guidelines for the Los Angeles Department of Water and Power.

Our Changing Coastlines: the Intersection of Geologic Processes & People

2020-2021 Jahns Distinguished Lecturer – Cheryl Hapke

Dr. Cheryl J. Hapke has decades of experience in studies of coastal geology and processes of coastal change as they relate to societal issues. She is presently the coordinator of the Florida Coastal Mapping Program and holds a research professorship at the University of South Florida’s College of Marine Science. She also runs a private consulting company: Coastal Science Solutions. She earned her Ph.D in coastal geology from the University of California, Santa Cruz and spent over 20 years as a research scientist with the U.S Geological Survey before taking early retirement from federal service in 2019. Her expertise spans a variety of coastal geomorphic settings, including barrier islands, rocky coastlines, and carbonate coasts. She currently is focused on helping coastal communities with sea-level rise adaptation planning.

Dr. Hapke’s presentation will provide a glimpse into the professional career of a research scientist  who’s passion of coastal geology has taken her from the steep slopes of the Big Sur Coast to the barrier islands of NY battered by Hurricane Sandy to the island beaches of the Gulf of Mexico. Regardless of the location or the geomorphology of the coastline, Dr. Hapke explores how coastlines change in response to storms, tides and sea-level rise, focusing on the vulnerabilities that changing conditions bring to communities, infrastructure, and the natural environment around them. Over the course of her lecture series, she will explore how geology and humans intersect at the coast and how science can be used not only to understand how a coastal system works but also how that knowledge can be used to help managers, planners, and decision-makers best balance natural processes and societal needs.




Sponsored by AEG Oregon Chapter

Moderators: Sarah Kalika and John Sager

The Walker Lane - An Incipient Plate Boundary Dissecting the American West and Potential Heir to the San Andreas Fault

The 2019 Ridgecrest earthquakes in eastern California and 2020 Monte Cristo Range earthquake in western Nevada were a reminder that the Walker Lane (WL) is a fundamental part of the North American-Pacific plate boundary. Since ~30 Ma, western North America has evolved from an Andean-type margin to a dextral transform as marked by arc retreat, orogenic collapse, and inland steps of the San Andreas fault system. Inception of the WL in the late Miocene coincided with a change in relative plate motions, east shift of the southern part of the transform to the Gulf of California, and development of the Big Bend of the San Andreas. Dextral shear was favored in the WL, as it paralleled the new plate motion while aligning with the Gulf of California and bypassing both the convergent bottleneck of the Big Bend and relatively rigid Sierra Nevada block. The WL currently accommodates ~20% of the dextral plate motion (~10 mm/yr). In contrast to the continuous 1,100-km-long San Andreas fault, the WL is marked by shorter discontinuous faults. Progressive NW-younging in the onset of deformation (~10 to <4 Ma) and a general decrease in both length of and offset on dextral faults indicate NW propagation of the WL. The WL ends near the south end of the Cascade arc directly inboard of the Mendocino triple junction. Continued northward migration of the triple junction and NW-propagation of the WL suggest that they may eventually intersect off southern Oregon in ~7–8 m.y. The primary plate boundary may then step inland to the WL, similar to the late Miocene shift to the Gulf of California. Thus, the WL provides a superb natural laboratory for analyzing the initiation and progressive development of a major transform fault. Integrated analyses of the late Miocene to recent evolution, Quaternary faults, recent seismicity, and GPS geodetic data are critical for deciphering the progressive development, current earthquake hazards, and potential future evolution of this incipient plate boundary.


Dr. James Faulds is the Nevada State Geologist, Director of the Nevada Bureau of Mines and Geology (NBMG), and professor at the University of Nevada, Reno (UNR). NBMG is a research and public service unit of UNR and is the state geological survey of Nevada. Faulds is a structural geologist with 30+ years of experience. He has been with UNR and NBMG since 1997, first as Professor and then serving as NBMG Director since 2012. He earned his BS at the University of Montana, MS at the University of Arizona, and PhD at the University of New Mexico. He has studied crustal deformation in many parts of the world, including much of the western US, western Turkey, and New Zealand. His research has focused on how fault systems initiate and evolve through time. In recent years, he has been analyzing the favorable structural settings and exploration strategies of geothermal systems in the western US, Turkey, New Zealand, and elsewhere. His geothermal journeys have included short-term appointments with the BRGM in France and both GNS Science and the University of Canterbury in New Zealand (as an Erskine Teaching Fellow) while on sabbaticals. He has published over 100 papers and dozens of geologic maps. He has also taught courses in structural geology, tectonics, geothermal exploration, and field geology, while serving as advisor for more than 25 graduate students.

Dr. Rich D. Koehler is an earthquake geologist specialized in characterizing the timing and frequency of past earthquakes (paleoseismology) and the implications of this information for engineering geologic applications and seismic hazard assessments. He holds geology degrees from UC Santa Cruz (BA), Humboldt State University (MS), and University of Nevada, Reno (PhD). He is currently an Assistant Professor with the Nevada Bureau of Mines and Geology at the University of Nevada, Reno. Dr. Koehler has previously held positions in private consulting and state government including 6 years as the senior earthquake geologist for the State of Alaska. Dr. Koehler’s research has been conducted throughout the western US and internationally. He has also provided technical support for water storage dams, nuclear power plants, and multiple crude oil and natural gas pipelines.


Dr. William C. Hammond is a professor of geodesy and geophysics in the Nevada Bureau of Mines and Geology at the University of Nevada, Reno. His research involves using space geodesy to study active processes in the solid Earth. These processes include tectonic and seismic cycle deformation with application to hazards, mountain building, geophysical loading, tectonic controls on geothermal resources, mantle processes, and interactions between tectonic and magmatic systems. Recently he has published academic research papers using GPS and InSAR to study vertical motion of Earth’s surface and its interaction with the climate system. He currently operates the MAGNET GPS network in the western Great Basin and eastern Sierra Nevada. He currently serves on the National Academy of Science Board of Earth Science and Resources, and an NSF seismic and geodetic facility advisory committee. Recent past service includes chairing the NSF EarthScope Plate Boundary Observatory advisory committee, serving as secretary of the Geodesy Section of the American Geophysical Union, and as Associate Editor for the Bulletin of theSeismological Society of America. He is author or coauthor of ~100 articles, book chapters, maps, conference proceedings, guidebooks, and reports. He has earned degrees in applied mathematics and geophysics, and was a postdoctoral researcher at the US Geological Survey in Menlo Park, California.

All Photos Credit: James Faulds

Mount St. Helens

Mount St. Helens, located in southwest Washington, erupted 40 years ago this year.  Several engineering features were constructed to mitigate the immediate and long term impacts from the eruption and subsequent debris avalanche, mud flow, and flooding.  These features included stabilization of the Spirit Lake blockage, a gated outlet structure and tunnel to maintain a safe post-eruption lake level at Spirit Lake, and the Sediment Retention Structure (a sediment retaining earth dam  on the North Fork of the Tuttle River). New studies are currently being performed to reassess the hazards that still exist to establish what actions may be necessary to  to maintain these existing projects and continue to protect the downstream communities. This work is being accomplished through cooperative joint efforts of the U.S. Forest Service, the U.S. Geological Survey, and the U.S. Army Corps of Engineers. The 3 person panel will discuss ongoing and planned work in the following areas: Debris blockage characterization, a planned exploration program in 2021; Geophysical surveys (seismic and GPR) of the eruption debris blockage at Spirit Lake; Seismic Hazard Mapping;  and, dam safety issues with respect to the blockage, and tunnel outlet.


  • Geologic, Geomorphic, and Hydrologic Context for Management of Spirit Lake - Jon Major, Research Hydrologist, USGS

​Jon Major is a research hydrologist with the U.S. Geological Survey Cascades Volcano Observatory in Vancouver, Washington. He received his B.S. from University of Dayton, M.S. from Penn State, and Ph.D. from the Department of Geological Sciences at the University of Washington.  He has worked on groundwater flow in landslides, mechanics of deposition by debris flows, post-eruption sediment transport and streamflow hydrology, geomorphic responses to dam removals, and analyses of debris-flow and flood hazards at volcanoes in Washington, Oregon, Alaska, El Salvador, Chile, and the Philippines. He is a fellow of the Geological Society of America (GSA), and has received the GSA E.B. Burwell Award , the GSA Kirk Bryan Award, and a U.S. Department of Interior Award for Excellence of Service.

  • Managing a Volcanic Debris Dam Geohazard Utilizing Dam Safety Principles - Rene' Renteria, P.E., Geotechnical & Dam Safety Program Engineer, USDA Forest Service, Pacific Northwest & Alaska Regions

René Rentería has practiced geotechnical engineering for 35 years, with 25 years working for the USDA Forest Service, and 10 years involvement on the Spirit Lake project.  Rene’ specializes in unstable slopes geologic modeling and geotechnical risk assessment.  Rene’ obtained a dual degree B.S. in Civil and Forest Engineering from Oregon State University in 1985.  He is a registered Professional Engineer in Oregon. 

  • Spirit Lake Debris Blockage Explorations and Site Characterization - Jeremy Britton, Senior Geotechnical Engineer, Portland District, U.S. Army Corps of Engineers

Jeremy Britton has been with Portland District, USACE for 18 years, during which he has worked on several Mt. St. Helens related projects. He has a Ph.D. from Virginia Tech in geotechnical engineering (2001) and is a registered Professional Engineer.

All Photos Credit: USGS

Dams and Levees Lessons Learned Symposium - (Sponsored by Schnabel Engineering)

Conveners – Bruce Hilton, Holly Nichols, Cassandra Wagner and Keith Richards

Risk Assessments for Dams - led by a keynote presentation by Doug Boyer with FERC, who will be discussing the evolution of risk-informed decision making and where the industry is headed.

Dam remediation and investigations - led by a keynote presentation by Brian Greene with Gannett Fleming, who will discuss the recent installation of a cutoff wall at the East Branch Dam in Wilcox, Pennsylvania. Levee risk assessments, incidents, and repairs, led by a keynote presentation by Dave Rogers with Missouri University of Science and Technology, who is well-versed in levee case histories. ​

Engineering Geology for Tunnels and Underground Construction Symposium (Sponsored by PBS Portland)

Conveners – Paul Headland, Ike Isaacson, and Mike Piepenburg

Photo Credit: Paul Headland, Aldea Services Inc.

We will open this session with a 60-minute presentation by our Keynote Presenter Dr. Ed Cording, who will discuss the early days of engineering geology in underground practice, the development of the many of the key tenants of our work, and then fast forward to the continued application of our ability to observe and record our findings in ever-increasingly more challenging work conditions.  With over 60 years of experience in the field and around the world, Dr. Cording’s presentation should valuable lessons and insights for the listeners. Four other presentations will follow Dr. Cording and cover a wide range of topics (large and small diameter tunnels) and ground conditions (soft ground and rock) including; tunneling through carbonate reef structures and shale, developing a design for a microtunnel drive around a vertical curve through water-bearing sediments, and using directional drilling to locate old historic tunnels in the Rocky Mountains. With a wide variety of locations, tunnel sizes, and ground conditions, we hope there will be something of interest for all of our colleagues and hope you will join us.


Environmental Symposium 2020: RADON Occurrence and Remediation (Sponsored By Bryan Environmental and Princeton Geoscience, Inc.)

Conveners – Patricia Bryan and Loren Lasky

Photo Credit: Oregon Public Broadcasting

AEG’s Virtual Environmental Symposium 2020 will focus on Radon, a naturally-occurring, radioactive and carcinogenic emerging contaminant. This half day symposium, Wednesday afternoon, September 16, 2020 will feature an invited panel of Radon experts from academia and industry. Four in-depth presentations will highlight the latest USGS Radon mapping results and discuss the cutting-edge remediation techniques available now for mitigation of Radon, both in indoor air and in drinking water. 


Naturally Occurring Asbestos Symposium: Hindsight in 2020 and Lessons for the Future - (Sponsored by Gill Editing Online)

Conveners – Sarah Kalika and Mark Bailey

Geology as Art, courtesy of Asbestos TEM Labs StartFragment 

Chrysotile veins in serpentine – Diablo Range Fremont, CA. Thin

section – PLM w/ crossed polarizers

Asbestos occurs naturally across the United States and around the world within mafic and ultramafic rocks as well as soils derived from these rocks.  Join us to learn about naturally occurring asbestos (NOA) and elongate mineral particles (EMPs), what minerals are regulated as asbestos, where they are typically found, sampling and analysis methods, health effects from inhalation, and the varying regulations that apply to construction workers, the public, and waste soil.  We will additionally discuss emerging issues relating to efforts to further define worker protection procedures and limit the use of asbestos in consumer products.


Landslide Symposium: Seeking Stable Slopes in a Time of Rapid Change (Sponsored By Landslide Technology)

Conveners – Kevin McCoy and Casey Dowling

Photo Credit: Gannett Fleming 

Seeking stable slopes in a time of rapid change: This symposium will present case studies and field-based research of landslide processes and landslide hazard evaluation, management, mitigation and risk reduction in the frameworks of historical and contemporary societal needs. Topics include field studies of landslide activity, morphology, and geometry; comparative evaluation of historical and contemporary mining-related geohazards from a technical and social standpoint, and impacts of climate change on landslide processes.

Applied Geoscience Methods for Problem Solving - A Gallery of Practical Examples (Sponsored By University of Pennsylvania and Pali Consulting)

Conveners – Gerry L. Stirwalt and David F. Fenster

This technical session will focus on oral presentations that showcase a broad spectrum of practical examples illustrating how a range of geoscientific methods were creatively and innovatively applied to evaluate potential problems, collect and evaluate data pertinent to those problems, propose solutions to resolve them, and communicate information in a manner that enables all interested stakeholders to understand the geoscientific basis for the proposed solutions. 


Photo Credit: Landslide Technology

© 2019-2020 by

The Association of Environmental & Engineering Geologists.


AEG Meeting Manager

Heather Clark

T: 303-518-0618

Email (click here)

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