Research Interests

I am interested in developing both theoretical and observational tools in seismology to probe the Earth’s interior. Currently, I am working on two projects. In the first project, I investigate the propagations of body waves in the presence of a non-hydrostatic or deviatoric initial stress inside a medium. This type of stress is commonly observed inside the Earth’s upper lithosphere yet typically ignored in seismic-wave propagation theories. Therefore, it is important to examine and quantify its effect on seismic wavefield prior to applying seismological tools to study the Earth’s internal structures. In the second project, I develop a novel automatic phase-picking algorithm for processing seismic array data. This method is applied to identify core-reflected P waves (PcP) recorded by the Hi-Net array in Japan, and the extracted PcP times can be used to constrain the subsurface structures beneath Japan.


Education

2021-Present: Ph.D Candidate (Earth and Planetary Sciences), Harvard University, Cambridge, MA

2019-2021: M.S. (Data Science), Harvard University, Cambridge, MA

2015-2019: B.A. (Geology-Physics/Mathematics-Honors and Applied Mathematics), Providence, RI


Teaching Experience (see full CV for more details)

E-PSCI 165/265: Introduction to Seismology, Harvard University, Cambridge, MA (Fall 2023)

FS23I: GeoScifi Movies, Harvard University, Cambridge, MA (Fall 2022)


Mentoring Experience (see full CV for more details)

EPS Short-Term Program mentor, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA (August 2023)

SPHEER peer mentor, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA (July 2023)


Awards
American Geophysical Union Outstanding Student Presentation Award (2022)

Brown University Undergraduate Teaching and Research Award (2017)


Publications (* - In. Prep.)

Geng, Y. and Ishii, M. (in prep.). A Novel Cross-Correlation-Based Automatic Phase-Picking Algorithm for Seismic Array Data and its Application to PcP Arrivals

Geng, Y. and Ishii, M. (submitted 2022). Body-Wave Speeds and Polarizations in the Presence of an Initial Deviatoric Stress, submitted to Geophysical Journal International


Presentations

Geng, Y. and Ishii, M. (2023). Anisotropy in the Presence of an Initial Deviatoric Stress, Abstract DI42A-09 presented at 2023 AGU Fall Meeting, San Francisco, CA, 11 – 15 Dec.

Geng, Y. and Ishii, M. (2023). Heterogenous Structures beneath Japan Illuminated by Core-Reflected Seismic Waves, Abstract DI14A-03 presented at 2023 AGU Fall Meeting, San Francisco, CA, 11 – 15 Dec.

Geng, Y. and Ishii, M. (2022). A Novel Cross-Correlation-Based Automatic Phase-Picking Algorithm for Seismic Array Data and its Application to PcP Arrivals, Abstract S43B-06 presented at 2022 AGU Fall Meeting, Chicago, IL, 12 – 16 Dec.

Geng, Y., MacDougall, J., West, J. M., and Fischer, K. M. (2019). Seismic Anisotropy and Mantle Deformation beneath the Hindu Kush-Pamir Region, Abstract DI21B-0029 presented at 2019 AGU Fall Meeting, San Francisco, CA, 9 – 13 Dec.