Dr Voon Hui Lai

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About

An observational seismologist by training, I am interested in understanding seismic waveform complexities at very high frequency, generated by dynamic natural hazard processes and fine-scale structural heterogeneities in Earth's subsurface. I model and perform numerical simulations to study volcanic sources, debris flows, earthquake waveforms in complex environments, from sedimentary basins to core-mantle boundary.

At ANU-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 scientists can image the subsurface and detect natural hazard processes at an unprecedented spatio-temporal resolution. Past and present DAS deployments include NASA deep space network (Tidbinbilla, Canberra), ALIRT DAS array (Melbourne), and SISSLE experiment across Alpine Fault (Haast, South Island, New Zealand).

Position

2024 - present: Research Fellow, RSES, ANU.

2020 - 2023: Postdoctoral Fellow, RSES, ANU.

Education

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)

Service 

2021 - 2023: Member, DAS – Research Coordination Network (Data Management)

2021 - 2022: ECR Member, RSES Research Committee

2020 - 2022: Convener, RSES school seminar

Affiliations

science Research area

Research interests

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.

Current Research

  • Developing waveform modeling, source detection, and near-surface imaging capabilities for new-generation distributed acoustic sensing ( news )
Image
DAS_vhlai.jpg

Left: Local earthquake and traffic noise recorded on DAS array in Melbourne;
Right: Performing tap test to calibrate DAS array

Past Research

  • 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

Teaching information

Current educational roles

Sem 1 2022-2024 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.

Engagement

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.

Media Appearances

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”

Past activities

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outreach2_vhlai.jpg

 

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outreach1_vhlai.jpg

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

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outreach3_vhlai.jpeg

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!"

Location

Jaeger 2, Rm143

Publications

Visit my Google Scholar profile for most up-to-date publications.