AEG 2020 Virtual Annual Meeting Technical Program
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’s 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.
Hot Topics Panel - Walker Lane and Mount St. Helens
Moderators: Sarah Kalika and John Sager
- Walker Lane - James Faulds, PhD, Nevada State Geologist and professor in the Mackay School of Earth Sciences and Engineering at the University of
The Walker Lane shear zone is located in a portion of eastern California (east of the Sierra Nevada mountain range) and follows a trend northward into western Nevada. Recent large earthquakes, including the two major quakes in Ridgecrest (July 2019), followed by additional earthquakes Carson City (March and May 2020), Owens Valley (June 2020) appear to represent general movement trending northward into Nevada and appear to represent activity along this shear zone. The Walker Lane accommodates nearly 12 mm/year of shear between the Sierra Nevada – Great Valley Block and the North American plate. Geologists, including our panel speakers, have presumed that the Walker Lane might represent a transition to a new future plate boundary, assuming the activity on the San Andreas Fault gradually decreases. The San Andreas Fault currently accommodates 75% of the northward movement of the Pacific Plate.
- 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.
Dams and Levees Lessons Learned Symposium
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
Conveners: Paul Headland, Ike Isaacson, and Mike Piepenburg
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
Conveners: Patricia Bryan and Loren Lasky
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
Conveners: Sarah Kalika and Mark Bailey
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.
Applied Geoscience Methods for Problem Solving - A Gallery of Practical Examples
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.
Landslide Symposium: Seeking Stable Slopes in a Time of Rapid Change
Conveners: Kevin McCoy and Casey Dowling
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.