Dr Voon Hui Lai
An observational seismologist by training, I'm interested in (1) advancing seismic knowledge towards resilience against natural hazards; and (2) understanding the interconnectedness between Earth's systems. I deploy seismic arrays and perform waveform modeling (e.g., seismic source inversion, waveform simulation) to record seismic waves and reveal how waveform complexities are results of dynamic source processes and fine-scale structural heterogeneities.
My research journey has taken me to explore many intriguing problems including modeling volcanic sources and debris flows, simulating earthquake shaking in sedimentary basins, connecting deep earth processes to their mineral composition, and understanding how solid earth-atmospheric waves couple. At RSES, I deploy Distributed Acoustic Sensing (DAS), a new generation fibre-optics based seismic array, at places from rural outbacks to urban metropolitans, transforming how we perform subsurface and source characterizations at an unprecedented spatio-temporal resolution.
2020 - present: Postdoctoral Fellow, RSES, ANU.
2020: PhD in Geophysics, California Institute of Technology
2016: MSc in Geophysics, California Institute of Technology
2014: BA in Geophysics, University of California Berkeley
(awarded Departmental Citation)
2021 - present: Member, DAS – Research Coordination Network (Data Management)
2021 - present: ECR Member, RSES Research Committee
2020 - 2022: Convener, RSES school seminar
Keywords: natural hazards, seismic waveform modelling, structural imaging, seismo-acoustics
Our understanding of the dynamics of natural hazards and many geological processes relies on accurate description of the observed seismic waveforms - particularly the source and wave propagation term. Some challenges to describe these waveforms at high spatial and temporal resolutions include inherent trade-offs in seismic observation, lack of mechanistic models to explain the waveforms, and lack of sharp, fine-scale details in the velocity models. Incorporating multiple types of data set (e.g., broadband seismic, dense nodal array, distributed acoustic sensing, infrasound) and using seismic waveform modeling techniques (e.g. large-scale 2-D and 3-D numerical simulations, moment tensor studies) can provide new perspectives on these complex dynamic processes.
I apply these techniques to a wide range of contexts, from volcanic eruption to debris flow, from sedimentary basins to lowermost mantle, and from Earth to Venus.
- Developing waveform modeling, source detection, and near-surface imaging capabilities for new-generation distributed acoustic sensing ( news )
Left: Local earthquake and traffic noise recorded on DAS array in Melbourne;
Right: Performing tap test to calibrate DAS array
- Natural Hazards
- Presented mechanistic model to describe debris flow process observed during 2018 Montecito event ( news )
- Determined the evolution of seismic sources during the 2018 Kilauea caldera collapse
- Waveform Modelling
- Modelled fine-scale ultra low velocity zone (ULVZ) structures to constrain mineralogical composition and understand deep mantle flow
- Modelled prolonged ground motion shaking at high frequency due to shallow earthquakes at Los Angeles sedimentary basin
- Performed regional-scale simulation to study sharp velocity contrast across San Andreas Fault system may influence long term plate deformation
- Earth-atmosphere coupling
- Developed velocity models to understand infrasound wave-propagation, in prepration for future balloon-based infrasound deployment on Venus (Collaborators: infrasound research groups in Jet Propulsion Laboratory and ISAE-SUPAERO, France)
More info: http://vhlai-seis.github.io/research.html
Current educational roles
Sem 1 2022 Lecturer, Introduction to Global Geophysics (EMSC2022), ANU
Sem 2 2021 Supervisor of COE R&D student on independent research project
Past teaching experiences
2015 - 2019 Teaching Assistant, Caltech
• Taught 4 graduate-level courses: Advanced Seismology, Plate Tectonics, and Field Geophysics (twice)
2016 - 2019 Facilitator, Caltech Annual Teaching Conferences
• Developed and led 5 new workshops for incoming teaching assistants (TAs) at Caltech, focusing on American classrom culture, international TAs, communication skills, facilitating classroom discussions, and writing problem sets and exams.
I greatly believe in the aims of science engagement which is to encourage the public (and especially our younger generation and educators) to think actively about earth sciences and share with each other its awe and relevance in our own life. Since PhD time, I have many opportunities to participate and coordinate many different types of engagement projects. While I get to share my love of earth sciences in many settings, including at parade, public exhibitions, lab tours, on twitter, my proudest moment yet is to share this joy with my own close friends and family.
Aug 2022 AuScope in National Science Week video thread "Asteroids to Oceans: What makes research possible in Australia?"
Apr 2021 Canberra Times, “ANU researchers measure seismic activity of air force centenary flyover”
June 2018 Eyewitness News, ABC7, KABC-TV Los Angeles. “Caltech scientists working to predict mudslides”
May 2018 KPCC: Southern California Public Radio. “Seismometers can help predict earthquakes, but Caltech researchers think they might also signal mudslide warnings”
2019 'Science for March' at Beckman Lawn, Caltech
Theme: Seismology from Tectonics to Early Warning
Top: Group photo at our booth
Bottom: Kids creating their first 'earthquake' with unparalleled enthusiam
2019 'Doo Dah' Parade, Pasadena, California
Marched alongside Grand Marshall Seismologist Sue Hough and other female seismologists with a message "Drop, Cover and Hold On!"