Natasha Hendrick, geophysicist

Geophysicist

Natasha HendrickNatasha Hendrick received a Bachelor of Applied Science (Hons) in geophysics from the University of Queensland. After this she worked in the geophysics research group at Oxford University for 12 months and was involved with the investigation of fault mapping using seismic wave-guides in the North Sea. She returned to Australia to broaden her practical knowledge of geophysics and to develop a better understanding of how her research could best be used in oil, gas and coal exploration.

In 1994-97 she worked for a seismic processing company, Veritas DGC (then called Digicon Geophysical) in Pinjarra Hills, Queensland. She returned to study at the University of Queensland in 1997, where her PhD research topic was multi-component seismic wavefield separation.

She began working as a senior geophysicist with MIM Exploration in 2001 and is searching for new ways to enhance and exploit the shallow, high-resolution seismic data acquired from the coalfields of central Queensland.

Teachers' notes to accompany this transcript.
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Interviewed by Ms Marian Heard in 2001.

Contents


Learning to ask questions and follow dreams

Natasha, where and when were you born?

I was born in Brisbane in 1972, the year after my parents immigrated from England.

Were there any influences in your early life that led you into a career in science?

I guess so, because I have a brother and sister in science, too. My brother, Carl, is a civil engineer and my sister, Sarah, is an agronomist.

I grew up on property in the Redlands Shire, a relatively rural area south of Brisbane where I was always surrounded by animals and the outdoors. My father was an electrical engineer (he decided only 15 years ago to become a farmer) and he encouraged me to question the science behind my surroundings. So even without knowing it, I was developing the right attitudes for a scientist. I was also really strongly encouraged to read, and as a child I always loved books and reading.

My mother was a hairdresser in England, but since arriving in Australia she has worked towards achieving her Bachelor of Arts and her Masters in Sociology. From her I have learnt how important it is to work towards something you want and know you will enjoy, regardless of how much change that involves or how difficult it sometimes seems to reach your goal. She has inspired me to follow my dreams.

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Becoming sold on the adventure of science

You were a good student at primary school, but you enjoyed your high school years more, I think.

Yes. I went to a relatively small school, Moreton Bay College, just south of Brisbane, and I had wonderful teachers. In particular, the science teachers knew how to ‘sell’ the adventure of science. I became hooked on science, and by my senior year I was studying physics, chemistry, maths I and maths II. (I never did really like the study of biology, though, which meant that although I loved animals I could not follow my career choice as a vet scientist.) I actually ended up studying ancient history as my other speciality field – an odd combination of subjects, but very enjoyable to study.

Physics and maths II became my favourite subjects. With only seven students in each of those classes, the teachers could adapt the subjects to what the students found interesting and challenging. We had some great field trips. We measured the acceleration of the roller-coaster at Dreamworld; we used to go to the park and try to measure the velocity of the clouds drifting across; and we would go to the beach and look at waves. It was really interesting – and it taught me that science could be fun.

Would you say your high school teachers were important mentors to you?

I would. They were the people who really got me to look at science and maths as a career. In particular, my maths and physics teachers, Elaine Rae and Richard Walding, encouraged me to think about where my scientific talents could lead me.

Did you have many interests outside your maths and science studies?

I had a lot. I enjoyed playing ballgames and volleyball for school teams, and during high school I discovered that I loved singing – I joined the school choirs and even performed in amateur musical productions. I was also heavily involved with Girl Guides (I was training as a junior leader during my time at school) and did some more singing when I joined the Brisbane Gang Show and other Scout and Guide musical shows. I was always very busy and had a lot of fun.

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Moving into seismic exploration

Next, you enrolled at the University of Queensland. What degree did you choose?

Well, when I finished high school I knew I enjoyed maths and science, but I wasn’t certain about where I was headed professionally. I enrolled in an engineering degree, probably because my father had been an engineer, but it only took me a couple of weeks to realise it just wasn’t the course for me. There were hundreds and hundreds of students enrolled in engineering, and I really wanted to do something a little bit different.

Flicking through the university handbook, I found the interesting field of geophysics, the study of the physical properties of the Earth: things like how electrical current is conducted through rocks, how dense a rock is, and whether or not a rock is magnetic. The geophysics degree appealed to me as a combination of maths, physics, geology, computer science and a little bit of instrument engineering – a few subjects that I had studied before and some others that I hadn’t studied but seemed quite interesting. And so I switched to an applied science degree in geophysics.

My speciality within geophysics is seismic exploration, which involves recording artificially generated soundwaves, for example from a dynamite blast. These soundwaves travel down through the Earth and get reflected off different geological layers; as they bounce back towards the surface, we record them to map the subsurface of the Earth. Seismic exploration is typically used to search for oil and gas, and map the continuity of coal seams.

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An Honours project in seismic trace inversion

What work did you do for the Honours component of your degree?

It involved seismic trace inversion. Because the amplitude of the soundwave that we record at the surface of the Earth during a seismic exploration survey is actually related to the type of rock that the soundwave gets bounced back from, the seismic data can help us to determine what rock types are below the surface of the Earth.

My Honours thesis used a variety of mathematical techniques – I looked at different ways we could invert seismic data to get a geological section of the Earth from the data – and I compared and contrasted the techniques and offered some recommendations for improving the technology.

My Honours supervisor, Steve Hearn, was (and still is) a great mentor to me. He has encouraged me all the way through to where I am now in my career, and I have really appreciated his support along the way.

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Researching seismic wave guides and appreciating the facilities at home

What direction did you take after finishing your degree?

I found that I really enjoyed doing the research involved in my Honours thesis, and it was very exciting to be able to draw on all the knowledge I had been collecting through my undergraduate years so that I finally had the solutions to practical geophysical problems. I wanted to continue in research, so towards the end of my Honours year I applied for a Rhodes Scholarship. I was unsuccessful in obtaining the Queensland scholarship, but I made it to the second round and was awarded an Australia-at-Large Rhodes Scholarship. On completion of my Honours degree, I jumped on a plane and headed off for adventures in Oxford.

I became a member of University College, Oxford, and met some amazing young people from around the world. And I did a lot of travel around the UK and Europe. But I also did some research, working in the Department of Engineering Sciences on seismic wave guides. They are like low-velocity layers that trap the seismic energy beneath the surface of the Earth for a short time before the waves can come back up to the surface, where we record them.

The way that the seismic waves travel through a low-velocity layer gives us some information about that layer – about discontinuities, whether it’s fractured, whether it’s faulted. This is important because in the North Sea, off the coast of England, a lot of the oil and gas reservoirs sit within a low-velocity layer. If we can find the fractures and faulting within this layer, we can help the engineers design the best places to put the drill holes to extract the oil and gas most efficiently.

What are your lasting impressions of Oxford?

Oxford is full of tradition, including university life. Everybody belongs to a college. As an undergraduate you would actually study within your college and only attend lectures occasionally as part of a whole university. As postgraduates we tended to work more in our laboratories.

I guess the thing I noticed most was that Oxford is very, very old – the house I lived in was built in 1770, and the walls and floors were all crooked. And I suddenly realised how little I had appreciated the technical facilities that were available to me at my Australian university. Because of the age of the buildings and the great expense involved in keeping the university running, there never seemed to be enough computers or other modern-day technology to help the students study. But my year in Oxford was a great time.

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Weighing up the options

What did you do on your return to Australia?

I came back hoping for work in the geophysical industry, to gain some more practical experience. But at first I was offered some temporary work as a research assistant in my old department, the Department of Earth Sciences, at the University of Queensland. The research involved shallow high-resolution seismic reflection surveying on the southern extremities of the Great Barrier Reef, to help the geological interpretation of how the Reef was formed. So I had some wonderful trips to Heron Island – a lot of fun. We were trying to image the subsurface of the ocean floor, but it was relatively shallow: we were only looking 10 to 20 metres down.

At the end of that year, 1994, I found a full-time position with Digicon Geophysical (now called Veritas), a seismic processing company. I worked as a special project geophysicist, which is probably the closest you can get to being a research scientist in a production/processing company. I did get to try out new seismic technologies and test new theories for the oil and gas clients that we worked for, but after two years in a production environment I really felt I needed to get back to research.

Does that have anything to do with the trip you made to the United States?

That’s right. During my time working for Digicon I went to the US and worked on a Girl Scout summer camp for three months. That was an amazing experience – not much of a holiday, but a chance to get out and build up my self-confidence. It gave me time and space to decide where I wanted to head. And what I decided was to go back to university.

After my trip to Oxford I knew that I had good facilities in Australia and there was no reason to head overseas to do a PhD, so I stayed at the University of Queensland and worked with Steve Hearn – who had supervised my Honours project – as my supervisor. I really enjoy working with him, and we publish papers well together.

My employers were very supportive. I was still working for them while I helped design the research project, and because they were so keen for this type of research to be undertaken they actually contributed financially to it. I got additional funding from the Australian Petroleum Production and Exploration Association, a peak industry body, and the fact that both Digicon and APPEA were putting in money indicated that the project was of real interest to the industry. So I started full-time study in ’97.

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A hot topic for a PhD: multicomponent seismic exploration

What work did you do for your PhD?

It was all about multicomponent seismic – still a hot topic in the industry, generating a lot of interest. It differs from traditional seismic in how the soundwaves are recorded. Traditional seismic records them on a single microphone, called either a geophone when we are recording on land, or a hydrophone when we are recording in water. Multicomponent seismic records them on three microphones, orientated perpendicular to each other. It means that as well as recording the amplitude of the soundwave that comes to the surface of the Earth, we can also record its particle motion.

Particle motion is important because several different types of waves travel through the Earth. Two really important types are compressional (P) waves and shear (S) waves, and because each of these waves has a different particle motion orientation, by recording the direction of particle motion at the surface we can try to distinguish the compressional waves from the shear waves. When we are looking for natural gas or oil, our target is often a gas or a liquid. And because the two wave types respond differently to travelling through gas, liquid or solid, in seismic exploration we want to use the two wave types in partnership to help us determine whether we are actually looking at an oil or gas reservoir.

Did you have many field trips during your PhD?

There were not a lot of field trips for my research in particular, because most of it is computational programming. However, I have always been involved in the field trips for undergraduate students. I enjoy getting out and helping the undergrads realise the practical applications of what they’re learning in the field of geophysics, the reasons for learning these things. So that was my release.

Also, Steve Hearn has been really great in putting me in contact with people around the world. True, I’ve worked and studied at the University of Queensland, but in my research I network with people all over the world. I talk with young researchers in Europe, and I have contacts in America who provide data for my experiments and offer me technical assistance whenever I need it.

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Tracking a different seam: seismic exploration for coal

You recently returned to full-time work, while still finishing off your PhD. Where are you working now?

I started full-time work in April of this year, working in coal seismic as a senior geophysicist for MIM Exploration. Seismic exploration for coal is a relatively new application. It has a slightly different emphasis from oil and gas applications, primarily because coal is only a few hundred metres below the surface of the Earth, whereas oil and gas is typically a few thousand metres below the surface.

The other difference is that whereas we tend to have to go and find oil and gas, in general we already know where the coal is, and what we’re doing with seismic in the coal environment is trying to map the coal seam. Mapping any discontinuities in the seam is going to make for more efficient mining, with better mine plans before the miners get underground. It’s also going to improve the safety of the mining environment, helping to avoid roof collapses and
so forth.

I suppose some of the machinery used in coalmining will rely heavily upon these sorts of techniques, as well.

Yes, certainly. One of the techniques that MIM Exploration, in particular, uses in mining coal is longwall mining, in which an automated shearing machine mines a panel about 250 metres across. It is set up to follow the coal seam, and because coal is a much softer rock than the sandstone and shales sitting around it, the machine needs to stay on line and track along the seam. If the coal seam suddenly disappears or jumps up or down, and the shearing tool is suddenly cutting harder rock, you can damage a lot of equipment. It is also unsafe when that happens.

My work with MIM involves the type of research I really enjoy – not purely theoretical but very much applied. I get to take the theory of things that have worked before in the oil and gas industry, and manipulate them and modify techniques to make them work for the coal industry. This is research to help design practical solutions, using theory that probably already exists but manipulating it to make a new application.

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Attitudes and skills that underpin a rewarding science career

What skills do you think are needed in science today?

Certainly scientists need a strong background in their scientific field, but it’s also very important that they are enthusiastic about their topics, show initiative when they’re researching, and can persist when things don’t appear to go right the first time.

Scientists need computer skills, organisational and time management skills, and communication skills. Of these, I think communication is critical. It’s so important to be able to communicate what you’re doing. Your funding relies on it, and employment could rely on you being able to communicate accurately to other people what it is you actually do. It’s also really important to be able to communicate with scientists from other disciplines, because research projects these days are done, more often than not, by teams of people from different subdisciplines within science. You need to be able to work with each other to get the results you’re looking for.

What do you find are the most rewarding or exciting aspects of a career in science?

It’s exciting to be constantly trying to understand the environment around you. It is wonderful when the light switches on and you suddenly understand how something works. It is even better when you can use that additional knowledge to make life easier, cheaper or safer – or more enjoyable – for other people.

For me the most rewarding experience is being able to take something that is so theoretical, like how soundwaves propagate through the Earth, and turn it into something that’s so practical, such that a geologist can determine that there’s oil and gas 3000 metres below the surface of the Earth. That is really amazing, and I’m constantly excited by the prospect of how I can help people who are out in the field.

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A satisfying range of interests

Your research is clearly a very important part of your life. Have you been able to continue your wide range of other interests as well?

Yes, I have. Through Guiding and Scouting I have continued with my singing, and have been a long-time cast member of the Brisbane Gang Show. I’ve actually had a couple of very interesting years on the production team, also.

One of my favourite pastimes is canoeing, and I’m a canoe instructor with the Australian Canoe Federation. I took up canoeing through Guiding – I teach Guides and their leaders how to canoe, and take them on expeditions and so forth. That’s a lot of fun. I do a lot of other outdoor activities, too, like low ropes, for which I’m an instructor, and camping. I like doing outdoor education and experiential-type learning activities with kids.

I love working and interacting with young people. That probably started (and continues now) because I am so heavily involved in Guiding. For three years I represented Guides Australia on the Australian Youth Policy and Action Coalition, in Canberra, and that sparked my interest in youth issues. I’ve been involved in setting up a support network for young people in Guiding, aged 18 to 30 years, around the country. That was really exciting. I’ve also been involved in organising camps and activities at a statewide level for young people.

On the professional side of things, I really enjoy tutoring undergraduate students and helping them find what it is that they’re looking for in a professional career. I enjoy getting out to high schools and talking to students about careers in science, helping them to sit down and think about where they want to go – and to realise that choosing a career is not scary but a great adventure. They can do anything they want to achieve.

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Focusing on an exciting future

When you have submitted your PhD thesis, which is due in just a few weeks, will that make a difference to your career direction?

It will give me more time to focus on work, for one! I’m really looking forward to taking a break from the research topic to publish two or three papers from my thesis. Also I would like to focus more on industry applied research for a little while.

Where do you see yourself in 10 years’ time?

That’s a long time in a science career. In my industry, particularly, the trend in recent years has been for people to work on only two‑ or three-year contracts. But I have plans for what I’d like to do.

After a few years of working with MIM I would like to get back into some more research with my multicomponent seismic techniques, because the industry is just so interested in what is going on with multicomponent technology. The whole geophysical world is watching and monitoring what is going on, so it’s an exciting time to be involved in the research.

If that works, and the industry really starts taking off on multicomponent seismology, I guess I’ll be kept pretty busy working with those techniques. If it does not take off – and there is a chance of that, because of limitations in our current technology – I have the option to move into other fields of research within seismic exploration.

It is quite difficult, though, to get a research position in the industry, because funding for that has diminished over the last 10 years or so and you’re pretty lucky these days to be able to get a research position. I can probably get more of these applied research positions – half production, half research, applying different techniques to different situations. I’d like to work in that area, and chances are that within 10 years I may even have my own consultancy.

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