Jared Bryan, a fifth-year PhD candidate at MIT, discusses his seismology research with remarkable clarity and enthusiasm. Collaborating with Assistant Professor William Frank, he utilizes a blend of GPS data, satellite imagery, and seismic station information to explore the fundamental physics behind earthquakes. His passion for seismology ignited during undergraduate summer internships at the Southern California Earthquake Center, where he became captivated by the complexities of seismic velocity in fault zones.
“It’s definitely a more down-to-earth type of seismology,” Bryan humorously remarks. While it may seem like an unusual comment—after all, earthquakes are inherently terrestrial—Bryan’s humor captures the essence of his latest research, outlined in a groundbreaking paper recently published in Nature Astronomy: a study of seismic activity not on Earth, but in the stars.
Fostering Academic Curiosity
In MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS), PhD candidates are required to complete two distinct research projects. The first is typically aligned with their primary research focus and sets the groundwork for their thesis. However, the second project must delve into a different specialty altogether.
“This unique structure enriched my experience here,” reflects Bryan, who was unaware of this requirement upon joining EAPS. “It encourages curiosity and allows students to discover the intriguing work other researchers are undertaking.”
The diverse fields within EAPS create an atmosphere ripe for exploration, enabling students with a thirst for knowledge to investigate the interconnected aspects of Earth science.
“Everyone in our department is passionate about various topics, but we can’t pursue them all,” notes Frank, the Victor P. Starr Career Development Professor of Geophysics. “This setup inspires students to experiment and engage with different advisors, revealing the multifaceted nature of scientific exploration.”
Initially, Bryan was apprehensive that his second project might detract focus from his primary PhD work. However, Associate Professor Julien de Wit had been searching for assistance to analyze stellar observations he gathered in 2016. A star’s pulsating brightness indicated underlying changes, prompting Bryan to collaborate on the research.
“I was amazed to discover that the seismology we explored mirrored the practices of larger-scale global Earth seismology from the ’60s and ’70s,” Bryan shares. “This was an opportunity to reevaluate the foundations of my field from an entirely new perspective.”
Delving into “starquakes,” Bryan notes that while some principles are shared, the unique movements of stars result from various factors—including magnetism and the Coriolis effect—manifesting in multiple forms. Unlike earthquakes, star movements involve not only sound and pressure waves but also gravity waves, all at a vastly larger scale.
“It certainly takes some mental stretching,” Bryan admits, “especially since we can’t physically explore those distant places. In Earth seismology, it’s a true luxury to study locations that can be examined via Google Maps.”
Integrating insights from experts outside one’s primary field has its advantages. De Wit emphasizes that fresh perspectives and unconventional questions challenge foundational assumptions within established fields.
“The inquiries made by those from different areas can spark new ways of thinking that experts might overlook,” he says, commending Bryan for his openness to learning and facilitating enriching dialogues.
Understanding Tidal Resonance Locking
In the end, Bryan attributed the fluctuations in the star’s brightness to a phenomenon called tidal resonance. This occurs when waves interact harmoniously, amplifying their effects—much like pushing a child on a swing at just the right moment.
“Tidal resonance is achieved when the pushing frequency synchronizes with the swing, creating a lock where both frequencies may change,” Bryan explains, elaborating on how this analogy somewhat falters as they discuss complex celestial dynamics.
As stars evolve, tidal resonance can force massive exoplanets, often termed hot Jupiters due to their proximity to host stars, to alter their orbital paths. This fascinating migration mechanism helps unravel how some hot Jupiters end up so close to their stars, and it does so in a non-linear fashion that can involve speeding up, slowing down, or even reversing directions.
A key takeaway from this research is that tidal resonance locking might serve as an innovative tool for exoplanet detection, confirming de Wit’s hypothesis from the initial 2016 observations. If star brightness changes are linked to this resonance process, it could reveal hidden planets eluding current detection techniques.
From Earth to the Cosmos
While most EAPS PhD students don’t extend projects beyond exam requirements, Bryan relished the opportunity to contribute significantly to the burgeoning field of asteroseismology. “This experience underscores Jared’s enthusiasm for his work and his commitment to ensuring his contributions are meaningful within the scientific community,” Frank asserts. “He exemplifies the accomplishments we strive for in our students.”
Although De Wit hasn’t succeeded in persuading Bryan to pivot permanently to exoplanet research, both are eager to continue collaborating. Post-PhD, Bryan envisions a career in academia as a professor with a research lab, shifting focus toward volcano seismology and enhancing instrumentation in that domain. He remains open to the possibility of applying his Earth findings to extraterrestrial volcanoes, especially those on Venus and Jupiter’s moon Io.
“I aspire to bridge these fields,” he concludes, maintaining his enthusiasm for investigations spanning the cosmos and terrestrial realms.
Photo credit & article inspired by: Massachusetts Institute of Technology
