Gary Gibson is a Senior Seismologist and Principal Research Fellow at the University of Melbourne. We talk to Gary about his life-long work bridging relationships between seismology, engineering and geology.
What was it like to be a seismologist in the 1970s compared to today?
I began my earthquake seismology career in 1973 in Papua New Guinea investigating earthquake behaviour in the Owen Stanley Range. During that time I wrote my first earthquake location program, a development of which is still being used for earthquake location.
The data was very basic then, recording wiggly lines on rotating drums. Now we monitor seismographs minute by minute using continuous digital telemetry. I was on the International Seismological Centre’s Executive Committee for twelve years and Chair for four of those. Here global data is merged and reanalysed, with both data and results available for anyone to use. Seismology is an incredibly cooperative community around the world, and we are always learning and sharing what we know.
Tell us about your research with tailings dams
Australia has about one thousand earthquakes a year, mostly small. However, the 1989 quake in Newcastle measured 5.6 on the Richter scale and caused $4 billion damage. I feel the research we are doing at ATC Williams with tailings dams is vital for the potential long-term impact it can have to protect lives and the environment. I’ve found that working alongside engineers and geologists gives me a much better idea about seismology input to earthquake hazards.
It’s difficult to predict the impact of earthquakes on tailings dams due to their non-linear design. Unlike buildings and concrete dams, tailings dams can fail slowly over time. Behrooz (Ghahreman-Nejad) and I are working closely, and we are determined to develop a better solution. Having Sarah (Moein) on board now is a great asset, and her background studying seismology in Iran is very timely. We are working to make analysed data as useful as possible.
Your career has taken you around the world, which locations stand out for you?
One of the best experiences was six weeks walking a fault line in the Gobi Desert in Mongolia in the mid-90s. We walked about two-thirds of the 250km fault, including areas where locals are religiously prohibited but foreigners are allowed, so we were the first people there in forty years. We were investigating earthquakes in crustal areas which gave valuable new insights into intra-plate tectonics.
In 2010, central Chile suffered a magnitude 8.8 earthquake that lasted for over three minutes and caused a lot of damage. I was onsite there for a month with a group of engineers and scientists from New Zealand to conduct surveys. Chile is a world leader in long-period motion earthquakes, and it was remarkable to see how new buildings were designed and engineered to withstand damage. Chile is showing the world that the cost of solutions isn’t prohibitive and is small in comparison to the cost of damage and repair.
I also admire New Zealand’s dedication to rebuilding Christchurch carefully and mindfully so it can be stronger than before. I went there just after the second earthquake in February 2011 that caused the most damage. I’ve seen China rebuild entire cities in one or two years, but I think New Zealand is taking an appropriate approach in the case of Christchurch.
What do you look for in seismology students?
We get students from a range of physics, maths, engineering, even furniture design. The common trait is the ability to see anomalies and be driven to chase down answers. There is a lot of not going by the rulebook involved, as you can’t learn the character of local earthquakes from textbooks based on quite different geological and tectonic conditions. Seismologists who can work with engineers are needed for creating workable solutions.
Are you ever going to retire?
Unlikely. We need to keep increasing the number of people working in seismology, and there is always something new to learn.
Dr Sarah (Fatemeh) Moein
Dr Sarah (Fatemeh) Moein joined the ATC Williams Melbourne office in June in the position of Senior Geotechnical Engineer – Seismologist. We explore Sarah’s unique curiosity for brown coal mine settlement and rehabilitation, tailings dams and numerical modelling.
You have a specific career interest in coal mines and mine rehabilitation, tell us how that happened?
I moved to Melbourne from Iran in 2011 after applying for a research project on brown coal mine settlement in Latrobe Valley, sponsored by the Australian government. I studied batter (slope) failures in the Latrobe Valley open cuts in 2007 and 2011, which caused the closure of Princes highway for a few months, as the geotechnical risks were deemed to be too high.
I completed my PhD on ‘Investigating the consolidation behaviour of brown coal’ at Monash University, during which I was part of a Geotechnical and Hydrogeological Engineering Research Group (GHERG) team. Within the Research program, three broad themes were being driven forward. These are concerned with slope stability, rehabilitation and groundwater issues.
Later on, through my career, I had this chance to apply my knowledge on brown coal mine settlement into a major project, the Latrobe Valley Regional Rehabilitation project. My research work and thesis was used as one of the main references.
What projects have you worked on since?
I was a geotechnical engineer at Jacobs and then a senior geotechnical engineer at Golder. I enjoyed working on notable projects such as the North East Project Alliance (NEPA), West Gate Tunnel Project and Latrobe Valley Regional Rehabilitation project.
Do you have other career interests?
Yes, I am also a university lecturer. In Iran, I lectured at Shiraz Azad University after completing a master’s in engineering geology. As well as completing my PhD., I have also enjoyed sessional teaching at Monash University and Federation University.
What did you first think of life in Melbourne?
I remember that driving on the other side of the road was very strange at first, but it took longer to adapt to the Melbourne weather. In Iran, we have four distinct seasons, not four seasons in a day! Now that I am used to it, I enjoy the variations.
How are you applying your skills at ATC Williams?
I am conducting Probabilistic Seismic Hazard Analysis (PHSAs) for two mine projects at Mt Arthur and Costerfield. High and Extreme Consequence Category dams (according to ANCOLD Guidelines) often require reviews to existing PSHA reports using the latest information (i.e. earthquake catalogues, seismotectonic models). Information from traditional national seismic hazard maps (irrespective of their publication date) do not account for local seismic sources and are general information that should be used as a guide and not a set value for detailed design or revisions to previous designs.
In Iran, I worked for a consultancy that specialised in dam construction and seismology. Iran is located within an active zone from a geological point of view, so seismology is often necessary for all infrastructural projects. I’m enjoying using that background, updating my knowledge and applying it to tailings dam design. Moreover, I was working on a dam’s grout curtain design and applied a new method of analysing data named Secondary Permeability Index. These results are published as a journal paper “Evaluation of Damsites Groutability Using Secondary Permeability Index, Rock Classification (Case Studies)”.
Luckily, I had a month in the office before lockdown, so I was able to meet everyone and get a good start on these projects. ATC Williams was recommended as having a great team culture which is what I was looking for at this stage in my career, and I’m very happy to be here.