I’m proud to lead a dynamic research group, and 2024 has been a good year for us! This year, the SMU seismoacoustic group comprised four graduate students, a postdoc, and nine full-time research staff. This critical mass enables us to tackle unique and challenging research problems.
While journal articles don’t capture the full scope of our work, they are an important metric of our progress. This year, members of our group led three journal articles and contributed to a fourth. I’m especially proud that two of these articles were led by graduate students.
Miro Ronac Giannone, a PhD student, is doing pioneering work at the intersection of seismoacoustics and machine learning. His paper, published in Geophysical Research Letters—“Deep Multimodal Learning for Seismoacoustic Fusion to Improve Earthquake-Explosion Discrimination within the Korean Peninsula”—introduces a novel deep neural network model that fuses infrasound and seismic data for event discrimination. This study is the first to combine infrasound and seismic observations in a unified framework for discrimination and to quantify the benefits of using both types of data together. This work has important implications for better distinguishing earthquakes from explosions, essential for understanding seismicity and monitoring explosions.
Another PhD student, Ketan Singha Roy, published an innovative paper in Seismological Research Letters titled “Exploiting Signal Coherence to Simultaneously Detect and Locate Earthquakes.” He developed a technique that uses wavefield coherence between adjacent seismometers for detecting and locating microearthquakes. This approach stands out because it identifies smaller events than conventional methods, doesn’t rely on prior event templates, and requires only strategically placed clusters of sensors instead of dense networks. This method has potential to help illuminate faults and identify seismicity connecting larger earthquakes.
Junghyun Park, a research scientist in our group, authored a comprehensive analysis of a 23-year infrasound catalog for the Korean peninsula. This study documents sources of infrasound events—including nuclear tests, quarry blasts, and industrial explosions—and is the longest-duration regional infrasound catalog ever produced! The catalog represents the end product of an enormous amount of work, and also the starting point for a lot of follow-on work, such as exploring changes in the subaudible realm over time.
Finally, we contributed to a collaborative study led by Elizabeth Silber at Sandia on seismoacoustic observations of the OSIRIS-REx capsule reentry. This effort, detailed in the paper “Geophysical Observations of the 2023 September 24 OSIRIS-REx Sample Return Capsule Reentry,” highlights the unique measurements captured by a broad network of collaborators.
Naturally, not all of our research made it to publication this year. Many projects span multiple years, and I’m hopeful that much of our ongoing work will be published in 2025. Among the projects I’m excited about right now are two experiments with particularly promising early results.
The first involved a dense deployment of nodal infrasound sensors across campus during the total solar eclipse on April 8th. To complement our measurements, we also generated low-frequency sound with a giant subwoofer. Our research targets were gravity waves and the study of acoustic propagation in the urban boundary layer as the atmosphere responds to a sudden change in solar forcing. The second experiment saw the addition of high-frequency arrays embedded within two existing regional infrasound arrays our group runs. In this case, we aim to understand what new signals we can detect above 5 Hz and how high-frequency arrays enhance the capabilities of traditional regional infrasound arrays.
This year brought an exciting new tool to our repertoire: gaining hands-on experience with Distributed Acoustic Sensing (DAS). DAS is an innovative technique for measuring seismic wavefields using light and fiber optic cables. While it holds immense potential, it also introduces unique challenges. While much of our effort this year was devoted to the challenges, attending the SSA Photonic Seismology meeting in Vancouver this October was truly inspiring—it showcased the incredible work being done with DAS by other groups. I’m optimistic that our group will publish a couple of DAS-focused papers in 2025 and start contributing to this exciting field!
I won’t spoil the details of these various efforts, as students and postdocs will be authoring papers on these studies next year.
Lastly, much of our work is operational, focused on maintaining long-term seismic and seismoacoustic arrays. While this vital effort often goes unnoticed, it plays a crucial role in supporting government objectives and addressing real-world challenges. I take great pride in this aspect of our work, and it’s invaluable for our students to gain hands-on experience in managing world-class seismic instrumentation around the clock.
I rarely pause to look back, as my focus is usually on the exciting projects ahead. Writing this post, however, has given me a chance to reflect on all we’ve accomplished over the past year. These achievements are truly the result of the hard work of students, postdocs, and research staff, but it’s really rewarding to play a role in supporting and facilitating their success.