Interviews with Australian scientists

Teachers notes – Dr Leanne Armand
Marine micropalaeontologist

Introduction
Summary of career
Extract from interview and focus questions
Activities
Keywords

Introduction

Dr Leanne Armand was interviewed in 2001 for the Interviews with Australian scientists series. By viewing the interviews in this series, or reading the transcripts and extracts, your students can begin to appreciate Australia's contribution to the growth of scientific knowledge.

The following summary of Armand's career sets the context for the extract chosen for these teachers notes. The extract covers some of her fossil work and how she uses micropalaeontology to study sea temperatures and climate models. Use the focus questions that accompany the extract to promote discussion among your students.

Transcript of interview.

You can order the DVD from us for $15 (including GST and postage).

This interview was funded by the
Australian Research Council.

Summary of career

Leanne Armand was born in 1968 in North Adelaide. In 1990 she received a BSc from Flinders University. She became interested in palaeontology as an undergraduate and took part in fossil digs at Narracoorte Caves in South Australia, and at Alcoota Station in the Northern Territory. She received a BSc (Hons) from the Australian National University (ANU) in 1993, where her studies involved describing the stratigraphy and palaeontology of the Teapot Creek catchment area in New South Wales. In 1998 she was awarded a PhD in geology from the ANU. Her thesis work focused on the use of algae remains as an indicator of sea surface temperature changes and sea ice estimation. The algae remains were found in sediment cores taken from the southeast Indian Ocean.

Armand joined the Institute of Antarctic and Southern Ocean Studies (IASOS), University of Tasmania, in 1998 as an ARC Postdoctoral Fellow. Working with the Palaeo Environments Program at the Antarctic Cooperative Research Centre (Antarctic CRC) she further investigated the role of sea ice cover and sea surface temperature in past global climate change, especially in the area of estimating sea ice over the last 190,000 years.

In 2001 Armand became a postdoctoral researcher at the Antarctic CRC, working in the Biogeochemical Cycles Program. She continues investigating sea ice and in addition is researching biogeochemical cycles at certain sites between Australia and Antarctica, using algae collected in sediment traps. Her work is important to gaining an understanding of how sea ice and sea temperatures vary naturally over time and how this natural variation influences climate.

Extract from interview

Teapot Creek fossils: drawing on mentor influences and expanded skills

Your interest in fossils and palaeontology stayed with you throughout your degree. But although you decided that you preferred research to teaching and so enrolled in Honours at Flinders University, after six months you pulled out. Why was that?

I started Honours in Alice Springs, hoping to work on some fossils from Alcoota station, but I needed the facilities of the university at hand. The long distance between Alice Springs and Adelaide hindered the project considerably. So I decided to pull out at that time, and instead I went on to help organise a conference for vertebrate palaeontologists in Australia.

Needing a job and wanting to continue studying, I was able to then move to the Australian National University and start a part-time position as a fossil preparator for Professor David Ride – working with material from many different areas of New South Wales – and also to restart my Honours studies.

Did your part-time work contribute to the skills you needed in your Honours project?

Most definitely. It provided a sort of background training, helping me develop skills in research as well as fossil preparation.

I did my Honours work in the ANU Geology Department, as half thesis and half course work. My project was in the Southern Monaro, the Alps region, and this was one of the sites that I was given to work up from a geological and palaeontological perspective. The thesis work was specifically to go to Teapot Creek, where we knew there were fossils, to identify all the fossil sites in that catchment and also work out the geological formations in which the fossils were occurring. I did a lot of work in that area.

Did you have any important mentors at this time?

I certainly did. Besides Professor David Ride, Mike Archer (one of David Ride’s first students) had a great deal of influence in my palaeontological career. And from the geological perspective, Ken Campbell had a lot of input in my development.

Linking fossil algae, sea temperatures and climate models

After Honours you chose to stay at ANU for a PhD in micropalaeontology.

Yes. My PhD focused on a collaborative effort between the University of Bordeaux, in France, and the Australian National University Geology Department. My supervisors were Jean-Jacques Pichon at the University of Bordeaux and Patrick De Deckker at ANU.

I had a choice of about five research grant possibilities for my PhD. Four of those were with vertebrate palaeontology, with the large mammals of Australia, but there were not so many jobs in vertebrate palaeontology. There was certainly a niche in the micropalaeontological world that I could move into without so much competition, and I decided to take the opportunity to move into that area.

Just what is micropalaeontology?

Well, basically what you need for micropalaeontology is a microscope to look at these tiny fossils, and to observe and characterise them. I started my new research on fossil algae, and I have researched them for the last six or seven years. Algae can be thought of as the green slime that you find on your fishtank, and their skeletal remains are made essentially of glass, silica.

When algae die, they fall to the sediments or the bottom of your ocean or stream or whatever. I focused on looking at past sea surface temperature changes and sea ice estimation, based on the algae remains found in sediment cores taken from the ocean between Australia and Antarctica. I started off with two cores specifically, looking at which diatoms, or algae, indicated warm water or cold water environments. I used the diatoms to help provide indications of climatic change – whether sea surface temperature got warmer or colder, and whether sea ice advanced or retreated from Antarctica.

Why was this work important?

At first we weren’t sure how far we could develop the sea ice model, but it has become increasingly important as time goes by. Climate modelling is now a very important focus for all society: Where are we heading? What is the natural variability of the world in terms of its climate? Is it going to get warmer and warmer, or are we going to go into cold glacial periods like those of the past? My PhD study and also my current study, which has continued to some degree in this field, have been trying to give answers to modellers that will help them define the natural limits of climate variability. Sea ice, and also the sea surface temperature near Australia, are important in predicting future weather patterns or climate affecting Australia.

An edited transcript of the full interview can be found at
http://www.science.org.au/scientists/la.htm.

Focus questions

How can fossils give researchers a clue to past climatic conditions?
Why is it important for modellers to know the extent of the natural variability of the world's climate?

Activities

Select activities that are most appropriate for your lesson plan or add your own. You can also encourage students to identify key issues in the preceding extract and devise their own questions or topics for discussion.

Students use library and internet resources to investigate global climate change and how scientists study it. They then write a brief report on their findings.
Diatoms, ever wonder? (Earthguide, USA)
This is an online tutorial that teaches students about diatom biology, including aspects of diatom morphology, habitat and ecology. It includes a quiz at the end that students can take to check their understanding.
Australian diatom homepage (Monash University, Australia)
This site contains links to an interactive key and to species descriptions, as well as protocols for field sampling and laboratory preparation of diatom specimens. It focuses on the most common Australian freshwater diatom species. Ask students to collect and identify diatoms from nearby freshwater sources using the suggested procedures.
Tracking global climate change: microfossil record of the planetary heat pump (University of California at Berkeley, USA)
Exercises and experiments that integrate basic principles from physics, biology and geography to see how a large-scale planetary process operates over time. Using different foraminifera as indicator species, this site contains a good explanation of how and why microfossils are useful tools for scientists studying past climates.
Deep freeze (Australian Antarctic Division)
This is a Classroom Antarctica unit containing a number of activities that help students discover the influence and importance of Antarctica and the Southern Ocean in global processes.
How do we use cores for research? (Lamont-Doherty Earth Observatory, USA)
This is a clear explanation of how deep-sea sediment cores are used to help scientists research climate. Ask students to work through the presentation and then write a brief report on what they have learned.
Core (Columbia Education Center, USA)
In this activity students take their own ‘core’ and correlate the layers of the Earth found in the sample.

Keywords

Antarctica
climate modelling
diatoms
fossil
micropalaeontology sea ice
sediment cores