Drawing the Connection between Climate Change and Tectonics

Earth Observatory Blog

Drawing the Connection between Climate Change and Tectonics

Interviewee

In this interview series, we learn about the perspectives of the PhD students whose wide-ranging work contributes to the SEA2 Program and share what drives them in their research.

What comes to mind when you think of climate change and sea-level rise? 

The science of tectonics is linked to both in the most unexpected way. When an earthquake occurs, for example, a tectonic fault ruptures and causes short-term deformations, such as vertical land motion – a shift in the earth that influences sea-level rise by literally raising or lowering the seabed – it forms a link to climate change that is not immediately apparent.

An earthquake may also form long-term deformations that may not be instantly observed, with repercussions lasting any time between several weeks to even years. For instance, the island of Phuket, Thailand, has subsided more than 22 centimetres since the 2004 Mw9.2 Sumatran-Andaman EarthquakeTo grasp the true impact of sea-level rise on coasts, it would be vital to look at the tectonics of the region.

Looking at such large-scale earth movements is Grace Ng, a first-year PhD student at the Asian School of Environment (ASE) in Associate Professor Emma Hill’s team.

First-year PhD student Grace Ng (Source: Grace Ng/ASE)

Over the past year, she has been studying past earthquake events in the Sumatra region, which lies along the Sunda megathrust, a tectonically active region. "The researchers who had produced these slip models in the last two decades have spent years studying an event to understand the fault structure and rheology in the region," she shared.

Grace’s interest in geo-mapping is derived from her industry experience in the engineering geology field. "In one of my overseas projects, we had to look into why a hydrological dam had actually collapsed," she elaborated. "We were looking into the area’s geology."

"We also purchased some satellite data to study the general geomorphology of the area and it got me thinking about how everything was processed. All I received was the 'final product'," she divulged, "and I wanted to learn the theory and how they processed the data."

Grace in one of the mass rapid transit (MRT) tunnel systems, in one of the projects from her previous workplace (Source: Grace Ng/ASE)

As her work involved mostly the collection of ground information to build a 3D geological model like borehole data, geophysical survey data, and conducting lab tests on geological units, there were few projects dealing in climate change, which was one of her key personal interests. So, beyond work hours, she attended courses on climate change.

"My ex-boss was supportive of me pursuing my interests," she explained, "While the job didn’t have much opportunity for me to pursue work specifically in climate change, he encouraged me to sign up for online courses for free to develop my skills instead."

"The courses helped me feel sure that I wanted to pursue climate change," she affirmed, “and through these projects, I discovered my interest in remote sensing data. I thought it would be interesting to see how these two combined because satellite data can be used for so many purposes. As for climate change, it’s something where people don’t immediately see the link."

Speaking about the present, she enthused, "It just so happened that Associate Professor Emma Hill’s team was doing just the thing I was interested in, in both climate-related and satellite data."

"There aren’t a lot of opportunities for climate research in Singapore, but I wanted to learn more about it. And back then, I was looking for a Master’s degree or PhD, and, it was at that time when the SEAProgram launched. The project is quite meaningful to me as people seldom regard the vertical land motions caused by earthquakes as a huge factor in relative sea-level rise, especially in Southeast Asia," she added.

Grace giving a presentation at her last workplace, on challenges faced when modelling Singapore’s geology. Beyond work hours, she had taken up some climate change courses in pursuit of her personal interests, with the support of her former employer (Source: Grace Ng/ASE)

Delving further into her upcoming plans, she shared that she would be working on post-seismic modelling next, focusing on long-term deformation caused by a fault slip and happens gradually time because of the rheology of the mantle and earth’s crust.

"Down the road, I’ll be projecting the model into the future, which is eventually what we will be contributing to the sea-level projections. Our team plans to use the Bayesian method, which combines existing data to create synthetic scenarios to see the possible regional land motion that could happen in the future. I will then assimilate the different types of data in my literature review with a consistent reference frame to create this Bayesian model, such as GPS, tide gauge, and InSAR data."

On top of being able to work in the area of climate science, what else excites her most about her work right now?

"I guess it’s knowing that my research would be valuable to many countries, not just for Singapore," she responds. "We are focusing on the Southeast Asia region where there are many coastal cities."

"These cities are susceptible to flooding; if the sea level rises, they are the first ones to be affected. I hope that my work would be meaningful in helping the governments better plan their resources, such as the coastal protection measures and early warning systems for flood events."

"It excites me, knowing that the research is not purely for academic purposes but will also be helpful and practical for people."

And when asked if there was a song that represented her PhD thus far, she replies that it would be "The Climb" by Miley Cyrus. "The song speaks about striving and pushing on towards our goals and how we should not give up despite the many difficulties we may face along the way. I find the lyrics relatable and a good reminder to myself to not give up, and that I should enjoy the learning journey of the climb towards the end goal for my PhD."