Distinguished Lectureship - Speakers

Sarah Minson is a research geophysicist with the U.S. Geological Survey's Earthquake Science Center. Her research interests include determining the physics of earthquake ruptures, and estimating the slip distribution and predicting the ground motion from earthquakes in real-time for earthquake early warning. She received her B.A. from the University of California, Berkeley, and M.S. and Ph.D. degrees from the California Institute of Technology. Prior to her current position, she was a Mendenhall post-doctoral fellow with the US Geological Survey as well as a post-doctoral fellow at the California Institute of Technology. She is a winner of the Presidential Early Career Award for Scientists and Engineers (PECASE) and a Kavli Fellow (National Academy of Sciences and The Kavli Foundation). View Sarah's staff profile here.

The United States is developing ShakeAlert, an earthquake early warning system that will provide California, Oregon, and Washington with advanced warning of potentially damaging shaking. The hopes for early warning systems are high, but the reality of what can be expected from earthquake early warning is nuanced. Earthquakes don’t happen in an instant and don’t tell us how big they will become. This means that any forecasts that we make will be imperfect, and the amount of warning will be short; in many cases, only a few seconds of warning will be possible. In spite of these limitations, there could still be significant value to earthquake early warning, especially for people who are willing to adopt a “better safe than sorry” strategy of taking protective action for earthquakes that have only a small chance of causing damage. What kind of warning system would you prefer? One that issues alerts for weak shaking, but also sends alerts for many events that do not go on to produce strong shaking? Or an earthquake early warning system that issues alerts only once ground shaking is expected to be damaging, but there is an increased chance that the alerts could be issued too late? During this talk, you will discover how an earthquake early warning system works, how warnings are issued and how much warning is possible.

Ross S. Stein is CEO and cofounder of Temblor, Inc., Adjunct Professor of Geophysics at Stanford University, US Geological Survey Scientist Emeritus, Past President of the Tectonophysics section of the American Geophysical Union, and 2018 International Distinguished Lecturer of the Geological Society of America. A Fellow of the American Geophysical Union and Geological Society of America, Stein received the 2012 Gilbert F. White Natural Hazards Award from the American Geophysical Union, and received the 2000 Eugene M. Shoemaker Distinguished Achievement Award of the US Geological Survey. In 2003, the Science Citation Index reported that Stein was the second most cited author in earthquake science during the preceding decade; he was tenth most cited during 1900-2010. Stein frequently brings insights to public media interviews and public talks, and in IMAX and Discovery Channel films. He gave a 2012 TEDx talk, ‘Defeating Earthquakes,’ which has been viewed more than 50,000 times. Stein has given the Francis Birch Lecture, Gilbert White Lecture, a Centennial Plenary Lecture, and the Frontiers of Geophysics Lecture—all keynote presentations during annual Fall Meetings of the American Geophysical Union. Stein co-founded the Global Earthquake Model (GEM Foundation), and chaired its Science Board until 2015. He is a member of the Resilient America Roundtable of the National Academy of Sciences, and the Advisory Council on Catastrophes of Zurich Insurance.

Almost everything we love about the San Francisco Bay area is brought to us by the faults. Absent the San Andreas and Hayward faults, there would be no San Francisco Bay, the only deep protected harbor on the California coast, and so the wellspring of the Gold Rush. The Hayward fault lifts up the Berkeley and Oakland Hills, with their magnificent sunset views of the Golden Gate Bridge. The San Gregorio fault makes Big Sur ‘big.’ A bend in the San Andreas fault thrusts up the Santa Cruz mountains, the spine of the peninsula, and the Marin headlands. These coastal ranges temper the climate, bathe us in fog, and crown us in Redwoods. What I want you to see is that we enjoy the fruits of the faults every day. And so, we must learn to live with their occasional spoils—as befell the San Francisco Bay area in 1868, most famously in 1906, and 1989. You will see that while we can’t predict earthquakes, we know where and why the hazard is high. And we know how to erect buildings that can withstand anything the faults can hurl at them. During this presentation, we’ll move from the discovery of gold to the discovery of what an earthquake is, and how quakes interact, illustrated with four different demos. And, I’ll leave you with the means to assess your own seismic risk, to ensure the safety of your own family.

Susan Hough graduated from the University of California, Berkeley with a degree in geophysics in 1982 and received a PhD in Earth sciences from the University of California, San Diego in 1988. Since 1992 she has worked as a research geophysicist at the US Geological Survey in Pasadena. Her research interests include earthquake ground motions, induced earthquakes, historical earthquakes, and seismic hazard. She led deployments of portable seismometers following a number of damaging earthquakes, including the 1989 Loma Prieta, California, and 2010 Haiti earthquakes. She has co-authored over 120 articles, and was elected Fellow of the American Geophysical Union in 2009. She is now serving as President-Elect of the Seismological Society of America. In addition to technical articles, she has a long-standing interest in science communication, having authored five books on earthquake science for a non-specialist audience as well as numerous popular articles. She has further led USAID-supported capacity development projects in a number of countries including Nepal, Haiti, and Myanmar.

Seismologists spend their lives working to understand earthquakes, including earthquakes caused by human activities, so that we can understand and mitigate the hazard they pose. Fortunately for us all, large earthquakes do not strike frequently in any one place. Many of the most important past earthquakes occurred before the invention of modern seismometers. To understand these events, scientists draw on sleuthing skills to explore all available sources of data. In this talk, I describe some of the ingenious work that has been done to understand past earthquakes, and the lessons they can teach us about present-day earthquake hazard. I also discuss evidence that, while earthquakes induced by wastewater injection appeared to be a new phenomenon, there is evidence that humans caused earthquakes in a number of places, including Oklahoma and Texas, as far back as the early 20th century.

Arthur Rodgers joined Lawrence Livermore National Laboratory (LLNL) as a seismologist in 1997. He has worked on high-performance computing and computational seismology since 2004. This worked involved modeling of seismic waves from earthquakes and explosions. Dr. Rodgers has worked with teams on modeling earthquakes in the San Francisco Bay Area, as well as educational outreach with the California Academy of Sciences (2012), LLNL’s Science on Saturday (2015) and the American Museum of Natural History (2018). He obtained a B.S. in Physics from Northeastern University and a Ph.D. from the University of Colorado in 1993. He was a postdoctoral scholar at New Mexico State University (1994) and the University of California Santa Cruz (1994-1996). In 2010, he was a Fulbright Scholar to Grenoble France. He is currently a Visiting Researcher at Lawrence Berkeley National Laboratory and the University of California Berkeley Seismology Laboratory.

Computer simulations of earthquakes can be performed to understand the expected level and character of shaking for possible future events. Advances in numerical methods and the ever growing power of parallel processing supercomputers enable ever more realistic modeling of earthquake shaking, including geology and topography. I’ll describe how computer simulations are enabled by world-class supercomputers and how these simulations are generating ever more realistic motions for hazard and risk studies. This lecture will describe supercomputer modeling of earthquake ground motions with a focus on large Hayward Fault ruptures. The last major earthquake on the Hayward Fault, with magnitude 6.5-7.0, occurred on October 21, 1868. This earthquake caused significant damage to structures for the few thousands of people living in the “East Bay” at that time. Geologic evidence strongly suggests major earthquakes on the Hayward Fault occur about every 140-160 years. It has been 150 years since the 1868 event, but today approximately 2.5 million people live near the Hayward Fault. Therefore, simulations like the one on the Hayward Fault can help inform policy makers and the general public about seismic hazard and risk.

Katie Keranen is an associate professor at Cornell University. Keranen wants to understand how the world works, and to that end, studies earthquakes, volcanoes, and plate motion to understand deformation of the earth at slow and rapid rates. Keranen has a BS from Michigan Technological University, a PhD from Stanford University, and completed postdoctoral research with the USGS Geological Survey.  Before arriving at Cornell, Keranen was an assistant professor at the University of Oklahoma, and began studying induced seismicity when her house began shaking.

Induced earthquakes are triggered by humans, either by injecting fluid into the ground, extracting it, or impounding it behind dams. Induced earthquakes have occurred for a century, but in the past decade have become more prevalent in locations such as Oklahoma than natural earthquakes along most plate boundaries. These earthquakes create a new hazard and bring public attention, but they also create opportunities to study earthquake processes at atypical rates. Here, I discuss the sudden rise in induced seismicity, the relationship to oil and gas production including wastewater disposal and hydraulic fracturing, mitigation efforts, and new scientific advances made possible by this unintended experiment.
 

Frederik Simons is a geophysicist at Princeton University. Usually from the safety of his office, he analyzes data from digital global seismic networks to study the physical properties of the interior of the solid Earth, and from gravity satellite missions to weigh the ice sheets melting off its surface. To help increase seismic station coverage around the globe, he has been leaving his comfort zone by prototyping floating earthquake recorders in the oceans, and is now promoting the next big push in earth observation through the international initiative "EarthScope-Oceans". Simons joined the Princeton faculty in 2006. He is also an Associated Faculty member in the Program in Applied & Computational Mathematics and serves on the Executive Committee of the Program in Archaeology. Between 2010 and 2013, Simons was the Dusenbury University Preceptor of Geological & Geophysical Sciences. Previously, he was a Lecturer at University College London, a Princeton Council of Science & Technology Beck Fellow and a Department of Geosciences Hess Post-doctoral Fellow. Simons received a Ph.D. in Geophysics from M.I.T. and his M.Sc. in Geology from the KU Leuven in Belgium, of which he is a native. 

In the last few decades, seismologists have mapped the Earth's interior (crust, mantle, and core) in ever increasing detail. Natural earthquakes, the sources of energy used to probe the Earth's inside via seismic computerized tomography, occur mostly on tectonic plate boundaries. Seismometers, the receivers of earthquake wave motion, are located mostly on dry land. Such fundamentally inadequate 'source-receiver' coverage leaves large volumes inside the Earth entirely unexplored. Here be dragons! Placing seismic stations on the ocean bottom is among the solutions practiced successfully today. But there are exciting alternatives. Enter MERMAID: a fully autonomous marine instrument that travels deep below the ocean surface, recording seismic activity (and marine environmental data), and then reporting it by surfacing for satellite data transmission. This presentation will discuss a century of Earth imaging, a decade of instrument design and development, and the challenging – and wet – places that our scientific journey has taken us.

John Vidale is a Professor at the University of Southern California and Director of the Southern California Earthquake Center (SCEC). He completed his undergraduate studies at Yale University and earned his Ph.D. from the California Institute of Technology. Before returning to southern California in summer 2017, Vidale spent more than a decade as a Professor at the University of Washington, Director of the Pacific Northwest Seismic Network, and the Washington State Seismologist. Prior to that, he worked at the University of California, Santa Cruz and the US Geological Survey, and taught for a decade at the University of California, Los Angeles (UCLA). While at UCLA, Vidale was Director of the Institute of Geophysics and Planetary Physics. His honors include the American Geophysical Union's Macelwane Medal (1994) and being named American Geophysical Union's Gutenberg lecturer in 2009. The College of the Environment at the University of Washington named Vidale the 2011 Researcher of the Year. Vidale’s research focuses on earthquakes, volcanoes, Earth structure, and the hazards of strong shaking. 

Sudden mayhem. Tremendous impact. Unpredictable disruption. Is it any wonder earthquakes reserve a dark corner in our nightmares?

The Pacific Northwest is vulnerable to several shades of shakes:

• giant coastal quakes,
• isolated, miles-deep pops, and
• rips that could tear Seattle’s downtown apart.

The University of Washington’s M9 Project, led for several years by John Vidale, is making the repercussions of each type of quake clearer—and both less and more frightening. Vidale will share the latest research and prognoses, and offer insights on implementing early warning technologies in the Pacific Northwest, so we can gain a few seconds or even minutes before suffering the strongest shaking.

Stephen (Steve) R. McNutt is a volcano seismologist who worked half time for the Alaska Volcano Observatory from 1991-2012. He currently coordinates volcano seismology research for the School of Geosciences at the University of South Florida. His research interests include studies of source and propagation effects for volcanic tremor, low-frequency events, and explosion earthquakes; volcanic hazards assessments in Alaska, California, and Central America; the mechanical behavior of volcanoes including periodicity of eruptions; the effects of earth tides, sea level variations, and tectonic stresses on triggering eruptive activity; volcanic infrasound; and volcanic lightning. From July 1999 to July 2007 he served as Secretary General for the International Association of Volcanology and Chemistry of the Earth's Interior. He has served on several committees for the National Academy of Sciences, including the US National Committee for International Union of Geodesy and Geophysics, the US National Committee for the Pacific Science Association, and the standing Committee on Seismology and Geodynamics. He received his B.A. from Wesleyan University in 1977, his M.A. from Columbia University in 1982, and his Ph.D. in volcanology from Columbia University in 1985.

Seismology is used to study volcanoes in several ways. Seismic tomography, similar to medical tomography, is used to probe beneath volcanoes for their velocity and attenuation structure. This reveals the size, shape and location of bodies of molten rock underground, such as magma chambers and conduits. Models have become more detailed over the years as techniques and data have improved.

One result of such studies is a model of the structure of the volcano.  The model then provides a conceptual pathway to interpret the seismic activity that occurs prior to eruptions. A common pattern is an increase first in volcano-tectonic earthquakes caused by increasing pressure in the magma chamber communicated to faults in the rocks nearby. This is followed by low-frequency earthquakes, which are likely related to fluid processes involving magma or water and gases. Third, a continuous signal known as volcanic tremor occurs when magma reaches shallow levels near the vent.  Explosions and strong eruption tremor are associated with the eruption. Deep earthquakes sometimes occur as stresses readjust after the removal of magma. Such patterns, together with understanding of physics, have enabled successful forecasts of eruptions over a range of sizes and types.

The strength and character of some eruption seismic signals also provides clues to make near-real time assessments of eruptions while they are in progress. For example, the strength of eruption tremor is proportional to the height of the ash column. Lava fountaining from fissures makes stronger tremor than fountaining of the same height from cylindrical conduits. Magma with more gases makes stronger seismic signals and more fine ash, which can influence the amount of volcanic lightning!

These are the types of questions that Professor McNutt will explore as he discusses how the movement of magma causes volcano shaking and baking.

Dr. Justin Rubinstein is a seismologist and Deputy Chief of the Induced Seismicity Project at the United States Geological Survey (USGS) in Menlo Park, California. His research focuses on the ongoing surge of seismicity in the central United States and its relationship to oil and gas operations. This work includes developing methods to estimate the likelihood of earthquakes induced by oil and gas operations and field studies of seismicity in the Raton Basin (southern Colorado and northern New Mexico) and the Mississippi Lime Play (southern Kansas and northern Oklahoma). Dr. Rubinstein has worked on many topics related to earthquakes including: earthquake forecasting, controls on earthquake ground shaking, and causes of damage in the 1994 Northridge earthquake near Los Angeles. Rubinstein received his Bachelor’s Degree from University of California, Los Angeles and his Master’s and Doctorate from Stanford University.

The central United States is experiencing an unprecedented surge in earthquakes that began in 2009, rising from an average of 21 magnitude 3 and larger quakes to over 650 in 2014 alone. This increased earthquake activity is found in just a few concentrated regions around the country, with the lion’s share in Oklahoma. In 2014 there were more magnitude 3 and larger earthquakes in Oklahoma than there were in California. The increased earthquake activity is limited to areas of new and emerging oil and gas production and is undoubtedly caused by some of the techniques they use.

With a focus on oil and gas production and related techniques, I will discuss the many ways that humans can cause earthquakes. In the case of fluid injection, the primary source of the recent increase in earthquake rate, the fluid pressure increase from injection can be transferred many miles from the injection point. This fluid-pressure increase, in effect, lubricates the faults, making them more prone to slipping in earthquakes.

Recent research shows that the rate at which injection occurs strongly influences whether earthquakes will be induced. Areas with higher injection rates are more likely to have induced earthquakes. Other parameters, like the total volume injected and the depth of injection, are also believed to affect the likelihood of induced earthquakes. Additionally, local geological conditions are important. Despite similar injection practices, there is very little injection-induced seismicity in North Dakota in stark contrast to Oklahoma.

Given that these earthquakes are human-caused, there is hope that they can be minimized or even stopped. Slowing or stopping injection, changing injection depths, or trucking fluids to other locations have all been suggested as ways to curb induced seismicity. Regulators in a number of states have taken notice of the increased seismicity and are taking action to reduce the likelihood of damaging temblors. With future research to improve our understanding of fluid-injection induced earthquakes, we may be able to reduce their likelihood, something that is not possible for natural earthquakes. To accomplish this, though, it will require cooperation between all the stakeholders, including academic scientists, regulators, and the oil and gas industry.

Dr. Caroline Beghein is an associate professor in seismology at the University of California, Los Angeles, where she has been working since 2008. Her research involves studying the Earth’s deep interior and how it relates to surface plate tectonics using recordings of earthquakes all over the globe. Caroline Beghein received her BSc degree in physics in 1997 from the Université de Liège, Belgium, from which she graduated with high honors, and a MSc degree in solid Earth geophysics from the Institut de Physique du Globe in Paris, France, in 1998. She graduated cum laude from Utrecht University, The Netherlands, in 2003 with a PhD in seismology. Before joining the faculty at UCLA, she spent two years, from 2004 to 2005, as a postdoctoral scholar at the Massachusetts Institute of Technology, and she was a postdoctoral research associate in the School of Earth & Space Exploration at Arizona State University in 2006 and 2007. She was awarded the 2005 Arne Richter Award for Outstanding Young Scientists by the European Geophysical Union and the UCLA Assistant Professor Career Development Award in 2009.

The motion of the tectonic plates that divide the Earth's surface explains many geological features and events - from mountain building, to deep oceanic trenches, to earthquakes, tsunami generation, and the presence of volcanoes. These motions at the surface are driven by processes deeper inside the Earth, in particular by the overturn of the mantle through convection: hot, lighter rocks rise to the surface and cold, denser material sinks. This process causes solid rocks in the mantle to flow and deform over geological time scales. To understand what happens at the surface, we need to study the deep Earth interior. We cannot, however, directly sample rocks from the mantle. Instead, scientists use recordings of the waves generated by earthquakes to map the physical properties of mantle rocks.

In this presentation, I will explain how seismologists are able to take the temperature of the Earth’s interior using these seismic recordings and how we can detect the direction of mantle flow with seismic waves. I will also talk about recent advances that help us better understand the relation between the motions of the rigid plates at the surface and the deformation of the underlying convecting mantle.

During the decade 2004-2014, 18 huge earthquakes with seismic magnitudes larger than 8.0 struck around the world, sometimes causing horrendous destruction and loss of life. The annual rate of such events was 2.5 times greater than had been experienced over the previous century of seismological observations.  Deployment of global networks of very high-quality seismic, geodetic, and tsunami recording systems had preceded most of these events, allowing unprecedented signals to be recorded for these great earthquakes.

Geophysicists have analyzed the recorded waves and ground motions to determine details of each earthquake, advancing our understanding of these dangerous events.  Most of the earthquakes have involved surprises, rapidly revising scientific ideas about the behavior of huge fault ruptures and indicating the need for improved mitigation efforts.

The continent of Antarctica supports the largest ice sheets in the world. The history of the ice sheets is intertwined with the geological history of continent, involving processes such as mountain building, the response of the land to the weight of glaciers, and heat flow melting and lubricating the bottom of the ice sheet. Very little is known about the history of Antarctica because the ice sheets preclude the usual geological sampling and mapping, so seismology offers a method to “see through the ice” and understand the continent beneath. Recent advances in technology now allow autonomous seismographs to be deployed across the continent for the first time.

In this presentation I will discuss projects that are installing seismographs across Antarctica and summarize recent discoveries. New results reveal that East Antarctica represents an ancient continent, with an average geological age of greater than one billion years and with highlands supported by thick continental crust.  In contrast, West Antarctica shows evidence of recent tectonic activity, and high heat flow that may lubricate the base of the ice sheet. The seismographs record earthquakes from magma movement associated with volcanoes beneath the ice. The high mantle temperatures suggest low mantle viscosity, such that the response of the land to ice mass changes will occur within a few hundred years. These insights are changing the way we model the recent history of the ice sheet.

Seismograms also provide important constraints on the movement and forces acting on the ice sheets. “Icequakes” ranging from very small cracking events near the surface of the ice sheet to massive crevassing and calving episodes produce unique seismic signals that help reveal the physics of ice movement. The largest signals come from a unique region on the Whillans Ice Stream, where a 100 mile-long section of the ice stream lurches forward twice a day, triggered by ocean tides, and sending seismic waves traveling across the entire continent. This unusual behavior may signal the slowing down of this ice stream in response to changes in the amount of water along the ice stream bed.

The great ice sheets of Greenland and Antarctica are losing mass, transferring more than 500 billion tons of water to the ocean each year. Most of this ice enters the ocean from large outlet glaciers: rivers of ice draining giant ice reservoirs. Understanding the behavior of the outlet glaciers is critical for accurate prediction of sea-level rise. The outlet glaciers are changing rapidly, with large variations in flow speed, thickness, and extent. In Greenland, many of the largest glaciers also produce seismic signals the size of those from magnitude 5 earthquakes, strong enough to be recorded around the globe.

The number of glacial earthquakes is increasing, with six times as many earthquakes occurring in recent years as in the early 1990s. I'll discuss the discovery of these peculiar earthquakes, and show how combining earthquake data with GPS measurements from glaciers allows us to learn how the glaciers and ice sheets may be affected by changing environmental conditions. Ice, the tides, earthquakes, and meltwater combine in a fascinating and complex system with real implications for our lives, whether on the coast or in the middle of the continent.

Susan Hough graduated from the University of California, Berkeley with a degree in geophysics in 1982 and received a PhD in Earth sciences from the University of California, San Diego in 1988. Since 1992 she has worked as a research geophysicist at the US Geological Survey in Pasadena. Her research interests include earthquake ground motions, induced earthquakes, historical earthquakes, and seismic hazard. She led deployments of portable seismometers following a number of damaging earthquakes, including the 1989 Loma Prieta, California, and 2010 Haiti earthquakes. She has co-authored over 120 articles, and was elected Fellow of the American Geophysical Union in 2009. She is now serving as President-Elect of the Seismological Society of America. In addition to technical articles, she has a long-standing interest in science communication, having authored five books on earthquake science for a non-specialist audience as well as numerous popular articles. She has further led USAID-supported capacity development projects in a number of countries including Nepal, Haiti, and Myanmar.