Carl Heiland Lecture Series

Science in Service to Society: The Evolving Role of the U.S. Geological Survey

David Applegate
Director, United States Geological Survey

4 p.m., Friedhoff Hall, Green Center; Reception 3:30-4:00 p.m. and 5-5:30 p.m. with appetizers and drinks
Live streaming available: https://mines.zoom.us/j/97138652271?pwd=U0ZTMHlzRjIydkJCd04ySURPTnhNdz09

Jointly sponsored by Geology & Geological Engineering, Geophysics, Earth & Society Programs, USGS Geologic Hazards Science Center, Office of Global Initiatives

Abstract

Since its founding, the U.S. Geological Survey (USGS) has been dedicated to delivering science to inform decisions on some of the most consequential issues facing our nation. That was the case in 1879 when the order of the day was to characterize the resources of an expanding nation. It is very much the case today when a growing population requires safe and abundant water resources, critical minerals for our energy future, healthy ecosystems that foster our quality of life and fulfill our stewardship responsibilities, and disaster-resilient communities prepared to thrive despite the natural hazards we face in a warming world. Relying on a talented, dedicated workforce and a wide array of partnerships, the USGS combines foundational mapping, monitoring, remote sensing, and sampling of our changing Earth systems with the technical expertise to analyze, model, and interpret these data. We seek to deliver real-time situational awareness, long-term assessments, and other scientific information in ways that are relevant, meaningful, and useful to those who need it most, when they need it most.

Speaker Bio

David Applegate is the 18th Director of the U.S. Geological Survey, sworn in by Secretary of the Interior Deb Haaland on Aug. 15, 2022. Prior to assuming his official role, he exercised the delegated authority of the USGS Director beginning on Jan. 20, 2021. He served as the Associate Director for Natural Hazards since 2011, leading USGS emergency response activities and overseeing the bureau’s geologic hazards and coastal and marine programs. He co-chairs the interagency Science for Disaster Reduction working group and chairs the interagency Civil Applications Committee.

Applegate is a fellow of the American Association for the Advancement of Science and the Geological Society of America and is a past president of the Geological Society of Washington.

Applegate joined the USGS in 2004 as the first Senior Science Advisor for Earthquake and Geologic Hazards. Prior to that, he spent eight years with the American Geosciences Institute (AGI) federation of geoscience societies, where he directed science policy and served as the editor of Geotimes, AGI’s news magazine for the earth sciences. Applegate has also served with the U.S. Senate Committee on Energy and Natural Resources as the American Geophysical Union’s Congressional Science Fellow and as a professional staff member. He has taught at Johns Hopkins University and served as an adjunct professor at the University of Utah.

Born and raised in Chambersburg, Pa., Applegate has a B.S. in geology from Yale University and a Ph.D., also in geology, from the Massachusetts Institute of Technology. He lives in Washington, D.C., with his wife Heidi and two daughters.

Near-surface Geophysics in Alaska

Esther Babcock
Logic Geophysics & Analytics, LLC

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: Dr. Babcock will present case studies from field work in Alaska, focusing on electrical and seismic methods for engineering and environmental applications. Examples will include electrical resistivity tomography, ground-penetrating radar for anthropogenic and geologic targets, and seismic refraction. She will also provide insight for students’ future success in applied geophysics as an employee or consultant.

Speaker Bio: Dr. Esther Babcock received her MSc in Environmental Science from the University of Arizona and her PhD in Geophysics from Boise State University. Her geophysical experience focuses on near-surface investigations for geotechnical and environmental applications, and specifically remote investigations under Arctic conditions. She currently owns and operates Logic Geophysics & Analytics, LLC, based in Anchorage, Alaska, and conducts geophysical field work across the state, from the North Slope to the Aleutians.

The Overturning Circulation of the West Antarctic Shelf Seas

Andy Thompson
California Institute of Technology

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: The observed acceleration of ice shelf basal melt rates throughout West Antarctica could lead to a destabilization of continental ice sheets and a significant increase in global sea level. The decadal-scale intensification in ice-shelf melt has been attributed to the transport of warm ocean water across the continental shelf and into ice-shelf cavities, yet a mechanistic understanding of controls on the magnitude and variability this heat flux remains immature. While interannual variations in ice-shelf melt rates have been linked to wind forcing at the continental shelf break, this process alone neglects the critical role of water mass transformation in coastal regions needed to close the shelf overturning circulation. This talk summarizes both observations and numerical simulations that provide insight into the three-dimensional overturning circulation of the Amundsen and Bellingshausen seas and highlights how narrow boundary currents determine heat and meltwater pathways as well as ice-shelf melt.

Speaker Bio: Dr. Andy Thompson is Professor of Environmental Science and Engineering at the California Institute of Technology and incoming Director of the Linde Center for Global Environmental Science. He is a physical oceanographer focusing on ocean circulation, mixing and transport. His group has expertise in processes that link the ocean to other components of the climate system in polar regions, including air-sea interactions, the dynamics of sea ice in the marginal ice zone, and physical components of the ocean’s carbon pump. His research group combines analysis of observations collected by satellite, ship-based and autonomous platforms with the design of high-resolution processed-based numerical simulations.

Physics-guided Learning-driven Seismic Inversion: Synthetic Practice to Field Applications

Youzou Lin
Los Alamos National Laboratory

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: Seismic inversion is crucial for many subsurface applications. However, the relevant data analysis capability for solving seismic inversion is inadequate, mainly due to the ill-posed nature of the problems and the high computational costs of solving them. Recently, machine learning (ML) based computational methods have been pursued in solving computational imaging problems. Some success has been attained when an abundance of simulations and labels are available. Nevertheless, ML models, trained using physical simulations, usually suffer from weak generalizability when applied to a moderately different real-world dataset. Moreover, obtaining training labels is typically prohibitive due to high computational costs and subject-matter expertise. On the other hand, many scientific imaging problems are governed by underlying physical equations. For example, the wave equation, describing how a wave signal is propagated through a subsurface medium over time, is the governing physics for seismic inversion. To fully unleash the power of ML for solving seismic inversion problems, we have developed new computational methods to bridge the technical gap by addressing the critical issues of generalizability and data scarcity. In this talk, I will go through the details of our recent R&D effort in leveraging both the power of ML and underlying physics. A series of numerical experiments are conducted using datasets from synthetic simulations to field applications to evaluate the effectiveness of our inversion methods.

Speaker Bio: Dr. Youzuo Lin is a staff scientist and team leader in the Energy and Earth System Science Group at Los Alamos National Laboratory. His research interests lie in computation and scientific machine learning methods and their applications in various geoscience problems. Youzuo received his PhD in Applied and Computational Mathematics from Arizona State University in 2010. After completing his PhD, he was a postdoctoral fellow in the Geophysics Group at Los Alamos National Laboratory from 2010 to 2014 and then became a staff scientist.

SEIS on Mars:  First Legacy after Four Years of Seismic Monitoring of Mars

Philippe Lognonné
Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France

In person: 4:00 p.m. Friedhoff Hall; Zoom webinar link: https://mines.zoom.us/j/95432461641
Reception 3:30-4:00 p.m. and 5:00-5:30 p.m.

Abstract: SEIS, the international seismometer of NASA’s InSight mission, operated on Mars from February 2019 until mid-December 2022. For the first time, a robotic seismometer installation was made on the ground followed by wind shield deployment. This allowed the Very-Broad-Band sensors of SEIS to reach ultra-low noise during much of the night. This lowered the detection threshold to M<3 in the InSight hemisphere and to M~4 in the antipodal one. Noise was much larger during the rest of each day, exceeding the noise recorded on the Moon but still 10 times less than the quietest sites on Earth in the 0.1-1H bandwidth.

            More than 1300 events were detected during two Martian years, including a Mw=4.7 marsquake, 34 teleseismic events with determined distances (and azimuths, giving locations, for half of them), six impacts confirmed by orbital crater imaging, two with very large craters and a thousand regional crustal high frequency quakes. During the windy period, SEIS also detected several thousand pressure drops associated with atmospheric vortices, and during sunset thousands of very shallow local thermal cracks. Even Phobos eclipses were detected.

            We present a summary of the achievements and successes of the SEIS/InSight science team and services. These include the first models for the subsurface, for the crust below InSight and between InSight and several epicenters, and for the mantle as well as the determination of the core radius. We present results in term of anisotropy, attenuation and scattering. Seismic source analyses have determined magnitude, depth and centroid moment tensors for the largest marsquakes and provided better understanding of impact processes, including partitioning of blast energy in the subsurface and atmosphere.

            Finally, the success of InSight has contributed to the return of seismology in planetary science, currently, four missions in development have seismometers with, hopefully, many more to come in the future. We therefore conclude with perspectives for the future of planetary seismology.

Speaker Bio

Philippe Lognonné is professor in Geophysics at University Paris Cité and planetary seismologist at the Institut de physique du globe de Paris. He performs his research in the Planetary and Space Science team he founded in 1996 and is director of the French National Observation Service in Planetary seismology.  His research is related to long period seismology, to the seismic coupling of telluric planets with their atmosphere and ionosphere and to Planetary Geophysics and seismology, including lunar seismology. In the last decade, he has been principal investigator of the SEIS experiment on the NASA InSight mission (landed on Mars by the end of 11/2018), lead co-investigator of the VBB seismometer in the JPL lead Farside Seismic Suite experiment to the Moon (to land on the Moon in 5/2025).

VISITING POSITIONS AND HONORS: Assistant visiting professor, California Institut of Technology/Seismo lab and JPL (1995), Institut Universitaire de France award, 2001,2014 Distinguished NASA Visiting Scientist, JPL, NASA, 2001, 2018, 2019 Miller Visiting Professor, Miller Institut for Basic Research, Berkeley, 2003, Visiting professor at UCLA in 2019. Other short terms at UCSD, UBC, ETHZ in 2005,2007, 2009, 2010, fellow of AGU (2019), Grand Prix in Astrophysics-Space Science from French Academy of Science (2020), Prix International d’Astronautique from the French Astronomical Society (2021), AGU Beno Gutenberg lecturer (2022).

Why Does the Moon Exist? Its Formation and its Perilous Early Fate

Erik Asphaug
University of Arizona

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: The Moon formed late, about 100 Myr after Solar System formation, and out of a more-or-less isotopically identical reservoir as Earth. It is almost all rock, with a small metallic core. These are difficult facts to reconcile, leading to competing theories for its origin by giant impact. I will review these theories in the context of “late stage” accretion, of which Moon (and Earth) formation might have been the last hurrah. Giant impacts are inefficient at accretion, even at low encounter velocity, producing escaping debris of about 1 lunar mass in any Moon-formation scenario, which is 20 times the mass of the Asteroid Belt. These debris would orbit the Sun until they are swept up by the Earth or Moon, or scattered, on a timescale 0.1-10 Myr. Due to its close proximity to Earth, this would have been a perilous epoch for the early Moon, whose very survival further constrains the collisions that formed it. I will conclude with a discussion about moon formation at Venus, or absence thereof.

Speaker Bio: Dr. Erik Asphaug studies planet and satellite formation by giant impacts, using numerical models to develop theories that can explain their diversity and complex geology. He also studies low-gravity geophysics of asteroids, comets and small moons, as well as physical properties of meteorites and returned samples. He is a science team member of ongoing and upcoming missions (Psyche, OSIRIS-REx, DART, Hera and MMX) and has led competitive Discovery mission proposals to perform 3D radar imaging of the interior of a comet nucleus. He is Science PI of a research lab that is advancing robotic exploration of the Moon and asteroids with an emphasis on expanding the diversity of the research and engineering workforce. He is an author of nonfiction, When The Earth Had Two Moons. He joined LPL in 2017, and before then was Ronald Greeley Chair of Planetary Sciences at Arizona State University, and before then, a founding professor of the planetary sciences group at UC Santa Cruz.

Source to Sink: Tracing Freshwater Beneath the Antarctic Ice Sheet

Matthew Siegfried
Colorado School of Mines

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: Beneath the Antarctic ice sheet lies an almost entirely unexplored water system of interconnected streams, rivers, and lakes that transports freshwater and sediment from the interior of Antarctica to the Southern Ocean. This enigmatic hydrosphere, hidden beneath 10s to 1000s of meters of ice, also harbors diverse microbial ecosystems and can modify flow of the overlying ice, but remains poorly understood given our remote observations. I will trace this freshwater from where it is created by melt at the ice sheet’s base, through active subglacial lakes beneath fast moving ice streams and outlet glaciers, and into the sub-ice-shelf cavity where it modifies how the ice sheet and ocean systems interact, demonstrating along the way how modern geophysical tools are transforming our perspective on the space and time scales over which the Antarctic ice sheet can change. Finally, I will conclude with perspectives on the new scientific and technological frontiers of subglacial hydrology that are needed to answer open questions on the total volume and the stability of the least understood freshwater system on Earth’s surface.

Speaker Bio: Dr. Matthew R. Siegfried is a glaciologist who runs the Mines Glaciology Laboratory, where the team uses satellite remote sensing techniques in combination with field-based and airborne geophysical methods to understand physical processes of Earth’s glaciers, ice sheets, and permafrost. He is an assistant professor in the Mines’ Department of Geophysics, is affiliated faculty in the Mines’ Hydrologic Science & Engineering Program, and is a faculty fellow at the Payne Institute for Public Policy. He is particularly interested in processes at the ice-bed interface, which lies at the intersection of glaciology, hydrology, geology, microbiology, and oceanography. Dr. Siegfried is committed to maintaining an open discussion of the changing cryosphere, having collaborated with institutions ranging from local elementary schools to the Department of State to facilitate conversations about the local, regional, and global impacts of changes at Earth’s poles. He serves as a scientific editor for the Journal of Glaciology, is a co-chair for the joint UNAVCO and the Incorporated Research Institutions for Seismology Polar Science and Technology Committee, is a member of the NASA ICESat-2 mission Science Team, and was a member of the final NASA Operation IceBridge Science Team. He received his bachelor’s and master’s degrees in Earth Sciences from Dartmouth College and his PhD also in Earth Sciences from Scripps Institution of Oceanography at the University of California, San Diego.

Geophysics and Computers: Together on a journey from the earliest CPUs, GPUs and into the clouds

Sverre Brandsberg-Dahl
Microsoft Azure

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Geophysicists were quick in recognizing the potential of computers to help them carry out the many calculations needed when working to assess subsurface properties. Geophysicists are also experts in leveraging mathematics to create the computational frameworks needed to solve the key tasks they rely on in this work, like wavefield modeling, inversion, and large-scale optimization. In this presentation I will review how the field of geophysics, or maybe more accurately, computational geophysics have evolved along with the evolution of computers as a framing for offering some thoughts on where this journey might lead in the future.

Although many of the mathematical methods rely on approximations in the physics and geometry of the problem (dimensionality), the frontier of computational geophysics has pretty much tracked the frontier of computing by progressively adopting more accurate mathematical models and better physics in their problem definition. At any time, geophysical algorithms for imaging and inversion were pushing the limits of what was possible with the best and largest computers, quickly turning the industry into a dominant player in the field of high-performance computing (HPC). The leading companies deployed HPC infrastructure that rivaled that of the national labs, using this ever-increasing capability to solve ever more difficult subsurface imaging problems, unlocking vital energy reserves as a result. Can the growth in compute power continue indefinitely?

There is no way of predicting this, but I will argue that the emergence of cloud computing along with the economic conditions surrounding the industry, are forcing the development and adoption of new approaches to computing. Cloud computing has been a game changer for so many things in society, including geophysics, but it can sometimes be hard to see how this is the case unless we unpack the ‘cloud stack’ within the correct context. The hardware and computers are maybe the same, but the cloud services offer up new and exciting ways to think about and address the computational challenges. Although I will not endeavor to provide firm answers to this question, I will review multiple, emerging, cloud-based technologies that can impact the field of geophysics and be leveraged by the many clever people that work in the field, from server-less architecture applied to solving large-scale modeling and optimization to the role of AI as manifested in the fast evolving field of very large language models.

By adopting a software-defined computational framework, I postulate that a similar computational growth rate that the field has benefitted from in the past can also be sustained going forward, allowing new insights to be gained and help provide real a foundation for tackling some of the truly hard geophysical problems that are still out there.

Speaker Bio: Dr. Sverre Brandsberg-Dahl is the CTO for Microsoft’s Energy Engineering organization. Here he works with a range of engineering teams to bring the latest technological developments in Cloud Computing and AI to the energy industry. With a passion for technology and innovation, he is helping to position Microsoft with customers, partners, and governments as they accelerate their adoption of cloud technology, while giving equal focus to the transition to clean power and emissions management.

Prior to joining Microsoft, Sverre spent 16 years in various technical positions across the oil and gas industry. Sverre holds a PhD from The Center for Wave Phenomena (CWP) at Mines and an MSc from The Norwegian University of Science and Technology.

No Heiland this week due to Spring Break

Distinguished Alumni Lecture: Volcano Seismology in the Aleutian Islands 

Matt Haney,
USGS/Alaska Volcano Observatory

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: The Alaska-Aleutian volcanic arc stretches across the north Pacific and is one of the most volcanically active regions on Earth, with over 50 volcanoes having documented eruptions in the past 300 years. In a typical year, between 1 to 3 significant eruptions occur along the arc in addition to several other episodes of non-eruptive volcanic unrest. Among the most active portions of the arc lies to the west of the Alaska Peninsula, in the remote Aleutian Islands. In this talk, I present analyses of seismic data from recent unrest at several Aleutian volcanoes including Bogoslof, Cleveland, Great Sitkin, and Little Sitkin. The employed seismic methodologies include array processing and time-frequency polarization analyses of volcanic tremor, moment tensor inversion of volcanic explosions, coda wave interferometry during dome emplacement, and modeling of seismoacoustic resonance within magmatic sills. Advancements in real-time seismic monitoring at volcanoes lead to earlier warnings of impending unrest and improved eruption forecasts.

Speaker bio: Dr. Matthew M. Haney completed a B.Sc. (1999) in Geophysical Engineering and a Ph.D. (2005) in Geophysics at Colorado School of Mines in Golden, CO. After his Ph.D., he worked as a  appointee in the Geophysics Department at Sandia National Laboratories in Albuquerque, NM, and as a USGS Mendenhall Postdoctoral Fellow at the Alaska Volcano Observatory (AVO) in Anchorage, AK. He received the J. Clarence Karcher Award from the SEG in 2007. From 2009-2011, he was an Assistant Professor at Boise State University. Since 2011, Matt has been a Research Geophysicist with the USGS at AVO. During 2020-2021, he served a 6-month detail as the Acting Scientist-in-Charge of AVO and from 2019-2022 he was a member of the Steering Committee of the Subduction Zones in Four Dimensions (SZ4D) Initiative. Haney is a member of the AGU, SEG, and SSA.

Variations and Healing of the Seismic Velocity

Dr. Roel Snieder
Colorado School of Mines

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract

Interferometric methods in seismology have made it possible to detect time-lapse changes in the seismic velocity with an accuracy of about 0.1%. I will show examples of detecting velocity changes in the laboratory, the Earth’s near surface, and in engineered structures. Perhaps surprisingly, the seismic velocity is not constant at all and varies with the seasons, temperature, and precipitation, as the weather does. In addition, the seismic velocity usually drops as a result of deformation. Most of these changes likely occur in the near surface or the region of deformation, and a drawback of using strongly scattered waves is that it is difficult to localize the spatial area of the velocity change. One of the intriguing observations is that after deformation, the seismic velocity recovers logarithmically with time.  The reason for this particular time-dependence is the presence of healing mechanisms that operate at different time scales. Since this is a feature of many physical systems, the logarithmic healing is a widespread behavior and is akin in its generality to the Gutenberg-Richter law.

Speaker Bio

Dr. Roel Snieder holds the W.M. Keck Distinguished Chair of Professional Development Education at the Colorado School of Mines. He received in 1984 a Master’s Degree in Geophysical Fluid Dynamics from Princeton University, and in 1987 a PhD in seismology from Utrecht University. In 1993 he was appointed as professor of seismology at Utrecht University, where from 1997-2000 he served as Dean of the Faculty of Earth Sciences. Roel served on the editorial boards of Geophysical Journal International, Inverse Problems, Reviews of Geophysics, the Journal of the Acoustical Society of America, and the European Journal of Physics. In 2000, he was elected as Fellow of the American Geophysical Union. He is author of the textbooks: “A Guided Tour of Mathematical Methods for the Physical Sciences”, “The Art of Being a Scientist”, and “The Joy of Science” that are published by Cambridge University Press. In 2011, he was elected as Honorary Member of the Society of Exploration Geophysicists, and in 2014, he received a research award from the Alexander von Humboldt Foundation. In 2016, Roel received the Beno Gutenberg Medal from the European Geophysical Union and the Outstanding Educator Award from the Society of Exploration Geophysicists. He received in 2020 the Ange Melagro Prize for his outstanding class Science and Spirituality. From 2000-2014 he was a firefighter in Genesee Fire Rescue where he served for two years as Fire Chief.

Women in Science

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Laurie Padman
Earth and Space Research

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Physical processes of environmental seismic sources revealed by surface wavefields

Wenyuan Fan
University of California-San Diego

In person: Marquez 126; Zoom webinar link: https://mines.zoom.us/j/95432461641

Abstract: Seismometers can record earthquakes and ground motions generated by various environmental, oceanic, atmospheric, and anthropogenic processes. However, these non-earthquake signals are often considered as noise due to their complexity and difficulty in interpretation, which has limited their use in observational and theoretical studies. In this seminar, we present results obtained from using a novel surface wave detection method. We analyze ten years of continuous records from more than 2000 seismic stations across the United States to identify and locate various unusual environmental seismic sources, including landslides, submarine landslides, and stormquakes involving the coupling of the atmosphere-ocean and solid Earth. Our findings demonstrate the richness and complexity of the continuous seismic wavefield and suggest exciting future research directions.

Speaker Bio: As an observational seismologist, Dr. Wenyuan Fan’s research focuses on advancing our understanding of seismic source processes, which includes earthquakes, slow earthquakes, and transient environmental processes, as well as their interactions and triggering mechanisms. His research program involves the development of innovative methodologies, the analysis of extensive datasets, and conducting onshore and offshore field experiments to examine seismic sources. Specifically, he uses seismic array techniques to provide a unique, high-resolution perspective on earthquake and environmental processes, which can evolve from mere seconds to minutes. He aims to gain a better understanding of seismic sources and ultimately, to contribute to the development of strategies to mitigate their associated hazards. He received his PhD from the Scripps Institution of Oceanography at University of California-San Diego in 2017. Following that, he was a postdoctoral scholar at the Woods Hole Oceanographic Institution from 2017 to 2018. He served on the faculty at Florida State University from 2019 to 2020 before returning to Scripps in 2020.