Dr Voon Hui Lai

PhD 2020
Postdoctoral Fellow

An observational seismologist by training, my research focuses on (1) understanding the underlying processes in natural hazards (volcanic eruption, debris flow, earthquakes) which is important for risk mitigation and (2) imaging small-scale heterogeneities along major structural boundaries that informs the long-term deformation process inside the Earth.

I observe these dynamics using several types of data including seismometers, infrasound sensor and distributed acoustic sensing (DAS); and model the observations with different techniques such as large-scale HPC waveform simulation and moment tensor inversion.

 

Positions 

2020 - current: 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)

Research interests

Keywords: natural hazards, structural-imaging, seismo-acoustics, seismic waveform modelling,

Our understanding of the dynamics of natural hazards and deformation processes depends on our ability to accurately describe the observed seismic waveforms - the source and wave propagation term. Some challenges to describe these dynamics at high spatial and temporal resolutions include lack of mechanistic models, inherent trade-offs in seismic observation, and lack of sharp, fine-scale details in the tomography models. My research directly addresses these challenges by using seismic waveform modeling techniques (e.g.  large-scale 2-D and 3-D numerical simulations, moment tensor studies) and incorporating multiple types of data set (e.g. broadband seismic, dense nodal array, distributed acoustic sensing, infrasound) to observe the seismic wavefield and 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 )

 

Past Research

  • Derived mechanistic model to describe debris flow process observed during 2018 Montecito event ( news )
  • Analyzed explosive eruption and caldera collapse process at Kilauea
  • Studied ground motion hazard posed by shallow earthquakes by modeling prolonged long-period shaking observed in Los Angeles basin (Collaborator: Rob Graves from United States Geological Survey)
  • Modelled sharp jump along San Andreas Fault system to understand its implication on long term plate deformation
  • Modelled fine-scale structures at the edge of Pacific LLSVP at core-mantle boundary to understand their impact on lowermost mantle flow and plume formation 
  • Developed velocity models to understand infrasound wave-propagation and plan for potential future balloon-based infrasounde deployment on Venus (Collaborators: infrasound research groups in Jet Propulsion Laboratory and ISAE-SUPAERO, France) 

More info: http://vhlai-seis.github.io/research.html

 

 

Groups

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

Current educational roles

July - Nov 2021 Supervisor of COE R&D student on independent research project

July 2020 - present Co-convener of RSES School Seminar

 

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.

 

Outreach

I am always interested in finding and creating more outreach opportunities. I believe outreach activites are unique opportunities to engage the pubilc (epsecially our younger generation and science educators) with exciting new discoveries and to empower them by providing reliable information and dispelling misconceptions. Please feel free to reach out for potential collaboration via email.  Below are highlights of my past outreach experiences:

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!"