Exchange Stories
Stories and Insights from US & Chile Exchange Participants
Meet the participants from the US & Chile Exchange Program.
This Program offers U.S. and Chilean based graduate students and early career researchers the opportunity for a month-long visit at a lab, observatory, field site, or other scientific institution with similar research interests goals in the partner country. This program fosters international collaboration and provide critical independent research opportunities for students and early career scientists.
Their Exchange Stories capture the discoveries, challenges, and camaraderie that made this expedition both scientifically enriching and personally rewarding. Dive in to hear their unique perspectives and reflections!
Javier Ojeda Vargas
Graduate Student
Universidad de Chile & Institut de Physique du Globe de Paris
Active Tectonics, Geodesy, Seismology
Exchange Participant Javier Ojeda Vargas
About Javier's research project
Javier’s research project aimed to analyze the transient aseismic deformation along the Chilean margin and explore its links to seismic signatures such as swarm episodes and the nucleation of large earthquakes during the last decades. For this purpose, he explores novel methodologies to exploit geodetic time series, especially those from GPS data. His project has benefited from geodetic and seismological analysis, enabling him to leverage diverse datasets for new insights into transient deformation processes and, especially, slow slip events.
During his stay in the US, Javier collaborates with Dr. Roland Bürgmann, professor and leader of the Active Tectonics group at UC Berkeley. Through his time at UC Berkeley, Javier built strong connections with leading researchers and graduate students in the field, laying the groundwork for future collaborative research.
He was able to quantify the contributions of seismic and aseismic moment rates along the subduction interface in Chile, results that improve our understanding of the physical mechanisms driving these transient processes but also reflect the inherent need for ocean floor geodesy developments along the Chilean coast to further explore these signatures in the near future and better understand their potential implications for seismic hazard assessments.
This project is part of Javier’s broader vision to enhance the integration of geodetic and seismological observations in earthquake research, particularly applied to his homeland and unique natural laboratory with the observation of overlapping slip processes revealing the dynamical behavior of the Chilean subduction.
Although we have made important improvements during this one-month stay, we believe that we set the floor for publishing this work in the near future. For now, our next step will be a presentation at the next Slow-to-Fast Earthquake workshop in Santiago, Chile, organized by the Science of Slow to Fast Earthquakes Network (Japan), which is also held in cooperation with SZNet.
Javier and Roland Burgmann's Active Tectonic Group at UC Berkeley
About Javier
I’m a Chilean geophysicist born in the southern city of Puerto Montt. I hold a PhD in Earth Sciences from the Universidad de Chile and the Institut de Physique du Globe de Paris, as well as a Master's degree in Geophysics from the Universidad de Chile. My research interests include a wide range of earthquake seismology and geodesy research, especially studying slip processes along subduction zones. Stay tuned to my current and past investigations at my research site.
I heard about the program thanks to social media and email updates from the SZ4D network. As well as my advisor's recommendation, who always encourages me to apply for different opportunities opened for early career scientists, especially this kind of grants that help us to discover new earth sciences departments and interact with outstanding researchers. Since my first short visit to Berkeley, I have been impressed by the work environment and great people working in the EPS and BSL, and I took the opportunity to come back in October to continue these collaborative efforts. This exchange certainly opened a lot of doors for me, including new opportunities to collaborate with peers and to understand how US-based researchers develop their science and share thoughts about the development subduction zone sciences.
Leoncio Cabrera
Postdoctoral Scholar
Universidad de Chile
Seismology, Volcanology
Exchange Participant Leoncio Cabrera
About Leoncio's research project
The main goal of my exchange was to study the interaction between earthquake and volcanic processes at the Chilean subduction margin, in collaboration with William Frank at the Massachusetts Institute of Technology (MIT). We primarily worked with a large volume of seismic data and explored the use of optical and radar images, thanks to additional collaborations with other MIT researchers and students specializing in remote sensing.
Our results show very interesting things. We built a high-resolution seismic catalog, allowing us to track different processes in detail. We are still working on the interpretation, so I don't want to get ahead of that, but the plan is to put it all together in a scientific publication, where all our findings will be presented.
Beyond the research conducted during my 3.5-week stay at MIT, one of the most remarkable aspects for me was the extensive interaction I had with other researchers. William’s team welcomed me warmly and made me feel like a part of their group. Additionally, I had the opportunity to engage with many other people from MIT and visiting researchers. Working in such a stimulating environment was incredibly inspiring, and the earthquake science team at MIT is undoubtedly one of those places.
Leoncio and William Frank's group at MIT
About Leoncio
I am originally from a small town in south-central Chile called Mulchén. I mention it because Mulchén is very close to the epicenter of the Mw 8.8 2010 Maule earthquake. I was still in high school at that time, but somehow it marked my path to become a seismologist. After several years studying and traveling, I am currently an assistant professor at the Pontificia Universidad Católica de Chile (UC Chile). As an anecdote, I started as a faculty almost at the same time I did my exchange at MIT. My main reason for applying for the exchange was to strengthen international collaboration between Chile and the United States and between our respective institutions, and to have the opportunity to work side by side with William and his group. For the near future, in January we have two events in Chile (the Slow to Fast Earthquake Workshop and the Ocean Technology Workshop, plus some field trips), so this time it will be William who will be in Chile. I am sure we will be able to continue collaborating in the future.
Flavia Rojas Guzman
Graduate Student / Research Assistant
Pontificia Universidad Católica de Chile
Volcanology, Structural Geology, Rock-fluid interaction
Exchange Participant Flavia Rojas Guzmán
About Flavia's research project
In the Southern Andean volcanic arc, volcanic chains are related to different structural domains controlled by the plate boundary scale stress field (Lara et al., 2006). Observations show that these volcanic systems are spatially and genetically related to fault intersections (areas where faults cross) rather than disconnected subsidiary faults within a given system (e.g. Veloso et al., 2020). Areas of fracture intersection have been associated with increased fluid permeability up to two orders of magnitude compared to a single fracture (Stanton-Yonge et al., 2023), which may offer a possible interpretation of how and why volcanoes are spatially related to fault intersections. One fundamental unresolved issue is why some intersecting fault systems are associated with these systems and many others do not show an apparent correlation between enhanced fluid flow within the same arc system. This suggests that there are likely other first-order influence controls. For example, punctuated local variation in the stress state close to volumes of rock within or surrounding fault zone intersections. In this project, we propose to address the question: What is the role of fault intersections on local stress state variations at different scales? For this, we are studying the Puyehue-Cordón Caulle and Nevados de Chillan active Andean volcanic complexes as they offer unique exposure to the problem identified. During my 3-week visit to The Ohio State University, Dr Ashley Griffith introduced the theoretical basis and applications of the 3D Boundary Element Methods (BEM), which is particularly effective in simulating mechanical interaction between geometrically complex faults like our study case (Crider and Pollard, 1998; Griffith and Cooke, 2004; Muller et al., 2005; Stanton-Yonge et al., 2016). We designed our approach to the study cases and now we continue working and collaborating with the research team on our research question.
For our first case study, the Puyehue-Cordón Caulle Volcanic Complex (PCCVC), we have already collected over 200 structural measurements of faults in the field, from seven outcrops at different distances from the fault intersections. From this data, we performed stress inversions using the Multiple Inverse Method (MIM) and strain inversions using Faultkin. We are currently analysing and comparing the inversions of the different zones based on their relationship with the fault intersections. One of our findings until now is that in the Cochamó structural site, located close to an intersection between the Liquine-Ofqui fault system and an E-W lineament, there is more than one stress state solution. Fig. 1 shows the stress and strain inversions for Cochamó structural site. The MIM solution (upper plots) represents the orientation of the principal stress axes derived from the heterogeneous fault-slip data set by generating a combinatorial number of groups extracted from the whole data set (Yamaji et al., 2005, Perez-Flores et al., 2016). The orientations of the calculated stress axes for each generated group are plotted onto separate stereograms (σ1 and σ3) and represented as a tadpole coloured according to the calculated stress ratio (φ = (σ2 − σ3)/(σ1 − σ3)), thus groups of tadpoles with similar colours and similar orientations indicate a compatible stress field solution (Perez-Flores et al., 2016). In this case, we can observe the first blue-coloured group that represents a solution with a vertical σ1 and a semi-circle distributed σ3, this distribution is because σ3 is very similar to σ2, which is associated with an extension in all directions that might be occurring due to the intersection of these structures. We can also observe a second solution in the yellowish-coloured group, with a horizontal σ3 and distributed σ1, representing a different stress state recorded in the same place. Further analysis will be done to make progress on our understanding of the influence of these stress variations due to fault intersections in geofluid migrations in the crust. We plan to submit this work during the following year.
For our second case study, the Nevados de Chillán Volcanic Complex, we submitted a paper to the Journal of Volcanology and Geothermal Research (Espinosa-Leal et al., part of Espinosa-Leal PhD project) which was recently accepted for publication. This work is entitled “Fault intersection-related stress rotation controls magma emplacement at the Nevados de Chillán Volcanic Complex” and recompiles data of tens of dykes and thousands of fractures from representative outcrops around the complex. We use these data to generate a conceptual model of the response of the different fracture sets to regional and the potential consequences in terms of magma emplacement (Fig. 2). We propose that N-S to NW-SE striking fractures become reactivated by fault intersection-related local stress field rotations. This favours NW-SE aligned magma emplacement, and the evolution of NW-SE aligned volcanoes.
Now, we continue working from a modelling approach using BEM. This will allow us to study the fault intersection behaviour under tectonically realistic stress boundary conditions imposed by plate interaction at the subduction margin in different stages of the subduction seismic cycle. We plan to submit this work during the following year.
About Flavia
My name is Flavia Rojas Guzmán, I am from Chile, and I am currently doing a PhD in Volcanology at The University of Manchester. I applied to the first version of the SZ4D exchange program while working as a research assistant in the FONDECYT project previously described (1210591). One of the researchers of the project told me about this great opportunity, which was perfectly adapted to my work plans and the development of the project. To complement the training I received during my Master’s and Engineering degree, and to fulfil the goals of the project, I required training on methods that allow us to perform stress and strain inversions of the structural field data (fractures, fault kinematics, etc) and to model the different state of stress responses. To do this, I proposed to work with an expert in the field of boundary element modelling, Dr. Ashley Griffith. I decided to apply for this exchange because I strongly believe that international collaboration is key in scientific research, as it allows us to interact with experts on different topics, improve the quality of our work and address problems in more efficient ways by learning from the experiences of other research groups. It also contributes to creating networks of scientists with different access to resources, knowledge, and ideas, which allows us to produce better results and move forward more creatively in answering our scientific questions. This experience was an extraordinary opportunity to be part of a global scientific environment and learn a new tool that is allowing us to better understand and address our research problem. It also provided me with perspective from different points of view which contributes to becoming a more rounded professional.
Stephanie McNamara
Graduate Student
The University of Colorado at Boulder
Geophysics
Exchange Participant Stephanie McNamara
About Stephanie's research project
This research exchange kick-started my thesis work on dune migration, provided valuable experience in planning and leading a fieldwork campaign, and offered a unique cultural experience that highlighted the interconnectedness of various subduction zone geohazards and local communities.
This fieldwork campaign would not have been possible without assistant professor, Tomás Trewhela and civil engineering undergraduate student, Felipe Espinoza from the Universidad Adolfo Ibáñez in Viña del Mar, Chile. Together, we set-up and monitored three short-term and three long-term dune-obstacle experiments at a coastal dunefield in Ritoque, Chile. We investigated sand flux unwind and downwind of two artificial “trees” with differing branch densities, as well as an array of tightly spaced pillars. We compared these experiments to an adjacent control group and used data from our nearby meteorological station and the contents of the upwind and downwind sand traps to investigate dune-obstacle interactions. Our key questions are: do obstacles fix or aggravate sediment transport? Can we expand these results to guide dune migration to protect local infrastructure? Wind conditions for the short-term experiment did not result in significant sediment transport, but Trewhela and Espinoza continue to monitor the long-term version of this experiment.
After my fieldwork campaign, I attended the Slow to Fast Earthquake Workshop and the Ocean Floor Observational Technology Workshop in Santiago, Chile. I also attended the pre- and post-workshop field trips where I got to learn about the formation of the Andes, network with other Earth Scientists, and visit the Chilean National Tsunami Warning Center. This experience deepened my understanding of the interconnectedness of subduction zone geohazards and their impact on local communities. While in Chile, I formed relationships with lab members and learned about their experiences with earthquakes, hillside failure, tsunamis, and sand transport in Viña del Mar. This research experience reaffirmed my passion for interdisciplinary Earth science research in coastal geohazards.
Pillar array, “trees”, and windtraps at the fieldsite
About Stephanie
I am a second-year PhD student in geophysics at the University of Colorado, Boulder. I earned my bachelor's degree in Physics, but I sought ways to apply my science to communities and ecosystems. That’s when I discovered the geophysics program and found my place in Earth Science. I am passionate about the intersection of human infrastructure and natural environments, community outreach, and global science.
My PI, Nathalie Vriend, forwarded the SZNet Chile/US Exchange opportunity to me and connected me with her existing collaborator, Tomás Trewhela. I was thrilled at the opportunity to conduct dune research for the first time, lead my own fieldwork, improve my Spanish, and immerse myself in Chilean culture. This exchange was an incredible opportunity for both personal and professional development. It provided a meaningful introduction to global Earth science and has inspired me to continue pursuing science with a focus on positive community impact.
Nate Klema
Pre-tenure Faculty
Fort Lewis College
Physics, Geomorphology, Volcanology
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Exchange Participant Nate Klema
About Nate's research project
In January 2025 Nate Klema travelled worked with the research groups of Cristian Escauriaza and Megan Williams developing their ongoing multidisciplinary research project in the Melimoyu Reserve in Chilean Patagonia. Nate spent a week in Santiago at the Pontificia Universidad Catolica learning about the area and the groups existing work and discussing ideas for building studies to better understand coupling between oceanic sediment transport processes and landscape development associated with Melimoyu Volcano. Nate then spent a week at the Melimoyu Reserve with student Martina Monastario deploying fiber-optic cable (from a kayak) to test the efficacy of distributed temperature sensing for understanding differences in fluvial cycles associated with a low elevation rain-fed catchment versus a glacial fed river system coming off the volcano. The team is planning to return to Melimoyu for a more focused field study of the upper Marchant River system adjacent to the volcano. They think this is an excellent location for studying feedback between volcanic, glacial, fluvial, and marine processes toward better understanding subduction zone landscape evolution dynamics.
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Checking data quality at the base station at the Melimoyu Reserve.
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About Nate
Nate Klema grew up in southwest Colorado where he developed an early interest in landscapes and their formation. He has an undergraduate degree in physics from Fort Lewis College and worked full time for 13 years as a guide on rafting trips through Grand Canyon National Park where he first realized how physics can be used to understand natural landscapes. He went on to pursue a PhD from University of Oregon studying volcanic landscape evolution with Dr Leif Karlstrom, which he completed in 2023. He has now returned to Fort Lewis College where he is an Assistant Professor of Physics in the Department of Physics and Engineering.
Deploying fiber-optic at Melimoyu
Camila Monge
Graduate Student
Pontificia Universidad Católica de Chile
Geodesy
About Camila's research project
The main goal of my exchange at Cornell University was to assess surface deformation in south-central Chile using InSAR, in collaboration with Dr. Rowena Lohman. During my time there, I investigated multiple sources of ground deformation, including anthropogenic changes linked to mining activity at El Teniente Mine, forearc uplift following the 2010 Maule earthquake, and previously unrecognized landslide deformation near the Diamante Caldera, close to the Chile–Argentina border.
These findings offer a multi-dimensional understanding of subduction zone deformation, showing how deep megathrust activity, shallow gravitational processes, and human-induced changes interact to shape surface deformation. This integrated perspective gives us the potential to better interpret surface signals, model geodynamic behavior, and enhance hazard assessments at multiple scales.
At Cornell, I had the privilege of working with Dr. Rowena Lohman, Dr. Matt Pritchard and the CRIttRS group (Cornell Radar Interferometry and Remote Sensing), a diverse and dynamic team using remote sensing to study a wide range wide range of phenomena—from volcanic activity to land surface changes associated with agriculture. The environment was scientifically stimulating and deeply collaborative—I learned a great deal through group meetings, paper discussions, and other academic events. At the same time, the team was incredibly kind and welcoming, making me feel like a true part of the lab from the very beginning.
This exchange not only helped advance my research but also laid the groundwork for continued collaboration. We identified overlapping interests and complementary expertise, and I’m looking forward to building on this work together.
About Camila
Ever since I can remember, I’ve been curious about the world and how it works. Growing up surrounded by earthquakes, tsunamis, and volcanic activity awakened my passion for understanding the subduction zone I live on—and its immense capacity to move and reshape the ground beneath my feet.
I studied Geophysics at the University of Concepción, where I was introduced to geodesy. It was space geodesy techniques, however, that truly captured my attention, opening up a world of possibilities to study Earth's dynamic processes and the signals they leave behind. I am currently pursuing a Ph.D. at Pontificia Universidad Católica de Chile, hoping to contribute to the advancement of frontier science in this remarkable natural laboratory of geophysical phenomena.
I first learned about the SZ4Net US-Chile Exchange Program through my advisor, Marcos Moreno, who has consistently encouraged me to see science as a collaborative effort, grounded in mutual support and the exchange of ideas. At Cornell University, Professor Rowena Lohman warmly welcomed me into her lab, where I became part of a generous, collaborative, and inspiring research group. It was a valuable experience that deepened my understanding of how remote sensing can be used to study Earth processes and reinforced the importance of doing science as part of a supportive community. I’m truly grateful for the opportunity and hope we’ll have the chance to collaborate again in the future.
Karissa Vermillion
Graduate Student
University of Houston
Geology, Thermochronology, Structure and Tectonics
About Karissa's research project
This exchange was my first foray into tectonic geomorphology. The main goal of this project was to determine if reactivated faults (i.e., the Atacama Fault for example) contributed to the relative uplift of the Coastal Cordillera in the southern Atacama Desert by using a combination of the following: (1) argon geochronology of interbedded tuffs in the gravels, (2) detrital zircon work to assess provenance, and (3) cosmogenic nuclide dating for exposure ages. Our work was predominantly focused in the Pan de Azúcar National Park, but we also investigated the Salado Canyon by Chañaral during our two field trips. This project is part of project Fondecyt 11240413, "The Behavior of a Subduction Wedge in an Erosive Margin: Influence of Ridge Subduction and Upper-Plate Faults on Along-Strike Morphostructural Variability Above the Atacama Seismic Gap,” where María Pía is the Principle Researcher, and I am a new collaborator. This project was funded by the Chilean science agency, ANID (Agencia Nacional de Investigación y Desarrollo).
While we don’t have results yet, we discovered some interesting things in the field. We identified multiple episodes of gravels and have a much better handle on the stratigraphy and possible tectonic controls. We collected three samples for argon geochronology, and were quite lucky in that these interbedded tuffs evaded the pervasive supergene alteration found in many places! We were also quite fortunate to find lenses of sand in one of the gravels and collected one sample for future detrital zircon work. We are working with the New Mexico Geochronology Research Laboratory for the argon analyses, and are hoping to send our samples out for irradiation this upcoming fall. These analyses, in tandem with geomorphic surface mapping, will be key in determining the appropriate locations for cosmogenic dating.
My host, Maria Pia was lovely and made me feel very involved with her department at the University of Andres Bello where I talked with the other professors and even attended a tectonics seminar. Additionally, I was able to work with two of her undergraduate students in the field, and it was great being able to guide them through making columnar sections in the field. We had a lot of fun in the Atacama Desert, and actually experienced a 6.4 earthquake while out in the field! I loved the Chilean culture and geology and would love to work there in the future if possible.
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Me (brown sweater) with Maria Pia and her two undergraduate students. We took this photo right after the 6.4 earthquake!
About Karissa
Karissa Vermillion is a third year Ph.D. geology candidate working with Dr. Peter Copeland at the University of Houston. She has previously obtained her BS from California State Polytechnic University, Pomona and a MS from New Mexico State University. For her doctoral dissertation, she has returned home to the San Gabriel Mountains in southern California to investigate tectonic processes spanning the Proterozoic to the Cenozoic utilizing a variety of geochronology techniques. She is passionate about integrating geochemistry, geochronology, and other geologic disciplines to better understand large-scale tectonics. In her free time, she enjoys relaxing with her cats, scuba diving, and learning Spanish.
Lucas Crisosto
Graduate Student
GFZ Potsdam
Offshore geodesy, Geology, data science, tectonics
About Lucas's research project
Lucas’ research focused on numerical modeling of the seismic cycle to investigate how different rheological behaviors reproduce interseismic deformation in Central Cascadia, in collaboration with Prof. David Schmidt. Using two-dimensional models, he compared elastic, linear viscoelastic, and nonlinear viscoelastic rheologies, showing how variations in rheology generate distinct horizontal and vertical deformation patterns, and underscoring the critical role of subduction zone geometry and material properties in shaping the velocity field.
Also, Lucas explored technical aspects of seafloor geodesy, with particular emphasis on pressure gauges and GNSS-A data, in collaboration with the Applied Physics Lab and William Wilcock’s group. At UW, he examined oceanographic sources of noise and uncertainty, evaluating their influence on offshore geodetic signals and emphasizing the need for sustained offshore geodetic monitoring, especially near the trench where vertical deformation remains uncertain.
This exchange marked the beginning of Lucas’ PhD research, highlighting the importance of integrating offshore and onshore geodetic observations to improve our understanding of subduction dynamics and enhance seismic hazard assessments. By bridging modelling and observational techniques, Lucas laid the groundwork for cross-disciplinary insights into subduction zone behaviour.
Lucas’ time at the University of Washington, particularly within David Schmidt’s research group, was a transformative experience that allowed him to interact closely with experts from both geophysics and marine sciences. These interactions fostered a dynamic and interdisciplinary environment that broadened his scientific perspective and significantly enriched the direction of his PhD research.
About Lucas
I am a geologist with a Master’s degree in Geophysics, currently a first-year PhD student at GFZ Potsdam. I was born and raised in Concepción, Chile, a region shaped by subduction processes and large earthquakes, which has influenced my interest in understanding seismic hazards.
My research focuses on subduction zone dynamics, driven by questions such as: How does the megathrust behave offshore throughout the seismic cycle? and What controls the variability of deformation along the trench?
During my exchange at the University of Washington, I had the opportunity to work closely with experts in the fields of both geophysics and marine sciences, which was extremely meaningful, allowing me to explore technical challenges and broaden my scientific perspective.
I look forward to continuing collaborations with colleagues at UW and elsewhere to investigate how seafloor deformation may vary and how mantle structures/properties influence it, with the aim of contributing to improved models of subduction zone behaviour and more reliable seismic hazard assessments.