Earthquake wave propagation through mysterious low-velocity structures at the core-mantle boundary
Barbara A. Romanowicz, Professor
Earth and Planetary Science
Applications for Spring 2025 are closed for this project.
Seismology has revealed mysterious patches with extreme seismic properties on the boundary from Earth’s liquid outer core to its rocky mantle. There still are many scientific unknowns about these structures which are called ultralow velocity zones. We do not understand what their origin is, what they are made of, or whether they are involved in the flow of material around them. We do know that the thermal and chemical interchange between the core and the mantle is important for mantle dynamics and Earth’s long-term evolution, but we still do not have a good idea about role the ULVZs play in these processes.
The best way to image ultralow velocity zones is to analyze waves from distant seismic earthquakes. Often scientists forward model such waves to get an idea about the properties of a specific ultralow velocity zone. We would like to take a more general approach and calculate how seismic waves look different dependent on a variety of parameters. Due to the massive computational cost, we hope to find relationships (possibly with the help of ML) that allow us to generalize our understanding of how certain seismic signals depend on ultralow velocity zone properties. We hope that this work will lay the ground for a better understanding for how ultralow velocity zones influence seismic wave propagation.
Role: The undergraduate student would become part of Prof. Barbara Romanowicz’s research group, and have the opportunity to work with Prof. Weiqiang Zhu. Some of the detailed advising would be done by Jonathan Wolf who is current postdoc working with both Prof. Romanowicz and Prof. Zhu.
The student would have the opportunity to learn about how seismic waves propagate through Earth, the underlying physics, and what observations from these waves tell us about global Earth structure. Specifically, the student will become expert on the mysterious ultralow velocity zones that we are trying to better understand. To do this, we envision that the student will systematically analyze computer-generated seismic data for different ultralow velocity zones, and will try to systematically understand how the data are different dependent on the detailed properties of the ultralow-velocity zone. In that process, the student will enhance their (particularly Python) coding skills and will learn how to use some of the computational tools that are common in seismology. Ideally, as the project progresses, the student would use machine learning to better understand how the seismic waveforms depend on the parameters of the ultralow velocity zone.
Qualifications: Required qualifications: We are searching for a student with a strong quantitative background, for example in geophysics, computer science, physics, applied math or similar. Prior coding experience is important. Most importantly, we are looking for a curious and motivated student who is excited to work on a challenging project with high scientific potential.
Day-to-day supervisor for this project: Weiqiang Zhu, Jonathan Wolf
Hours: 9-11 hrs
Off-Campus Research Site: Department of Earth & Planetary Science, 307 McCone Hall
Related website: https://bsl-group.github.io/