Obituaries Australia

Geoffry Norman Mercer, one of Australia’s leading applied mathematicians, died suddenly on 12 April 2014, at the age of 51. He was passionate about the sport of rogaining, and suffered a heart attack while competing in the ACT Rogaining Championships with his partner Alex Tyson. He is deeply missed by the mathematics and scientific community, both in Australia and abroad.

Geoff Mercer’s contributions to applied mathematics and epidemiology were cut short at the peak of his career. If Geoff was to categorise his research area he would probably say that he was a ‘real applied mathematician’ not just an ‘applied mathematician’. The distinction was important to him as he liked to work in areas that were intimately linked to applications. This led him to publish papers covering a wide range of interests, resulting in over 100 journal articles, and the award of $2.5 million in external grant funding, including ARC and NHMRC grants.

Geoff Mercer was born on 1 June 1962 in Adelaide to Nancy and Norman Mercer. Both his parents ended their formal education in primary school to go to work due to financial needs. However, they greatly valued education and Geoff went to the local state primary and high schools. Marion High was not renowned for academic achievement, but he was lucky as his cohort had a small group of similar students with a desire to learn and sights set on university. Family life was simple—a paper round, gymnastics, roaming around the foothills with mates on their bikes (a passion that never waned), beach and caravan holidays and endless card games where he learnt how to bet and the fundamentals of probability. When convalescing after having had his appendix removed, he completed the two weeks of maths work in a few days and just went on and completed the book. The teacher wisely provided another one and Geoff says he knew then that maths was what he wanted to do.

Geoff completed his BSc (Hons) in Mathematics (first-class) in 1984 from Adelaide University and later his PhD (also from Adelaide University) under Tony Roberts working on shallow water waves and center manifold theory (thesis title: ‘On standing waves and models of shear dispersion’). Geoff’s PhD thesis was a substantial piece of work, with one examiner noting: ‘This thesis deals with two distinct topics in mathematical fluid dynamics, each of which could constitute a slim but successful PhD. Together they comprise an impressive and substantial contribution.’ Neither of the referees required any changes to the thesis.

During the period 1985–93, Geoff worked as a tutor, firstly in the School of Mathematics and Computer Studies (South Australian Institute of Technology) and later in the Applied Mathematics Department (Adelaide University). The latter was mostly during his PhD. He was immediately singled-out by students to be the ‘tutor of choice’ since he would take time to explain difficult concepts and would never ‘put students down’. He always had time for the students despite the fact that he oversaw the computing classes, which had over 1,000 students.

On 11 January 1993, Geoff arrived at the University of New South Wales at the Australian Defence Force Academy in Canberra as an ARC-funded postdoctoral Research Associate working in the area of bushfire modelling. He immediately showed that he was a flexible person who could join a team and be relied upon to make a contribution. In a very short period of time, he established himself as a successful, productive researcher. Geoff remained at UNSW Canberra for 16 years in the following positions: Research Associate (1993–95), Senior Research Associate (1995–2000), Lecturer (2000–02), Senior Lecturer (2002–08) and then Associate Professor (2008). It was during this period that his research interests diverged from bushfire modelling into mathematical combustion modelling and heat transfer, flow through porous media, dispersion and hydrodynamics, mathematical biology, dynamical systems and movement in a threat environment. He published papers in such diverse areas as modelling breast-feeding through to agricultural spraying, wool scouring and optimal routes through minefields. It is also noteworthy that he published a paper with his partner Alex in the area of sexual health. Some of these problems came through his active participation at Mathematics in Industry Study (MISG) groups, where he was project coordinator on five occasions, a member of various MISG organising committees and a participant in many more problems. The MISG projects upon which he worked have been very successful, leading to ongoing interactions with industry and to successful ARC linkage grants. A high-profile MISG project Geoff moderated in Wollongong was on the shelf life of wine, for a South Australian wine company. This project led to an article and photo in the local newspaper, the Illawarra Mercury, and fitted nicely with Geoff’s love of a nice glass of red.

In February 2009, Geoff was appointed as a Fellow in Infectious Disease Modelling at the National Centre of Epidemiology and Population Health (NCEPH) at The Australian National University. He embraced an entirely new research area and, freed from teaching, he was able to quickly make significant contributions to this field, resulting in his rapid promotion from Research Fellow to Professor, leader of the Infectious Disease Epidemiology and Modelling group, and finally acting Director of NCEPH. As always, his interests were wide and he worked on projects studying dengue, pandemic H1N1, salmonella and campylobacter in the poultry food chain and Tuberculosis.

Geoff’s considerable success in a range of research areas was due to his ability to understand the fundamental mechanisms in an application (physics, biology or epidemiology) and how to translate this into meaningful mathematics, derive elegant solutions and write computer programs to perform the numerical analysis. He also had the rare ability to combine high-end theory with practical attention to data. In addition, he was equally adept at communicating his work through well-written publications and conference presentations. He was overwhelmingly the students’ choice for the best non-student talk at ANZIAM 2007 (The Cherry Ripe Prize) and, in February 2014, Geoff gave an excellent invited talk at ANZIAM 2014, which gave the audience insights into the impact of disease modelling on policy decisions.

Besides outstanding research, Geoff excelled in undergraduate and postgraduate teaching. He would have taught thousands of students and was known for his perfectly clear lecture notes and presentations. In his days at the University of Adelaide, at UNSW Canberra and at the ANU, he would have taught almost all applied and computational mathematics courses to both science and engineering students. He loved teaching, and even when his positions were classified as research only, Geoff would volunteer his time to teach courses in mathematical modelling.

Geoff made an outstanding service contribution to applied mathematics in Australia and New Zealand, especially to professional bodies such as ANZIAM and MISG. Most recently, he was Secretary of ANZIAM (2008–12), a key role involving the oversight and organisation of many society activities, as well as providing continuous support to the Chair and Treasurer. His advice, sound judgement and knowledge of ANZIAM history and procedure were invaluable to our professional body. In addition, he contributed to a wide range of other ANZIAM activities, such as being the founding Chair of the ANZIAM special interest group in mathematical biology, chair and member of the ANZIAM ACT branch, Secretary of the Engineering Mathematics Group, ACT representative on the Executive Committee of ANZIAM on numerous occasions, and member of various conference organising committees including ANZIAM 2002 and CTAC 2008. Furthermore. he was an editor for the Proceedings of the Engineering Mathematics and Application Conference 2007 and the Proceedings of the Computational Techniques and Application Conference 2008, both published as part of the ANZIAM Journal (E), and a subject editor for the journal Applied Mathematical Modelling. His contributions to MISG also included being an editor of the proceedings of the 2007, 2008 and 2009 MISG meetings.

Geoff played a pivotal and influential role in the support of applied and industrial mathematics in Australia and New Zealand. In addition, he used the multidisciplinary nature of his research to effectively promote the discipline of applied mathematics at a national and international level. He was also involved in the successful supervision of five PhD students and was the current supervisor of four PhD students. Geoff Mercer was a tireless champion and campaigner for the promotion of mathematics, particularly for research students. He was often heard muttering words such as ‘we must do more for the students’ and was always keen to seek travel funding for students to attend maths meetings.

Geoff’s outstanding achievements have been recognised by the joint award of the prestigious inaugural 2013 EO Tuck Medal ‘for outstanding research and distinguished service’. The medal, which is awarded by the Australia and New Zealand Industrial and Applied Mathematics division of the Australian Mathematical Society, recognised Geoff’s contributions to applied mathematics research, as well as his teaching and communication of research results, his supervision of PhD and master’s students and his community leadership. ‘Dr Mercer is a committed applied and industrial mathematician and has demonstrated through his enthusiasm, energy and sustained achievements that he well and truly meets the criteria for this mid-career award.’

Many would agree that Geoff was easy to get on with, which explains his wealth of collaborators from every state in Australia, across the Tasman, and overseas. Geoff has been described by many as a ‘quiet achiever’, but it was always clear that he had a lot to offer in all sorts of ways. Alex aptly described Geoff’s unassuming nature in her eulogy. When Geoff arrived home from ANZIAM 2013, she asked him how the conference was. He replied that it was pretty good and then, as an afterthought, he told her that he was given an award—the EO Tuck award. This was typical of Geoff!

Geoff’s skills and interests extended beyond academia. He was a keen traveller, bushwalker and skier, and was able to entertain others with stories of his adventures in Africa, South America, Nepal and around Australia. It was these interests that led him into the sport of rogaining, which is similar to orienteering except that it is completed over rugged natural terrain for up to 24 hours, with the added dimension of weighted controls and the need to ‘optimise a weighted travelling-salesman problem with time-constraints and spatially variable route impedance’. Geoff’s energy for rogaining led him to act as the ACT Rogaining Association president and secretary for many years, as well as the organiser and course setter for numerous rogaines, including the 2002 Australian Championships. His contribution to rogaining in the ACT cannot be measured. As stated on the ACT Rogaining Association’s website, Geoff ‘established many of the ways we [ACTRA] do things’ and he was always ‘a great source of wise counsel and thoughtful guidance for many people both competing and organizing events’. This is a clear example of Geoff’s skill in mentoring that he applied to all areas of his life.

Geoff was always able to establish a healthy balance between family and work life. From 1998 to 2011, Geoff was employed on a part-time (0.8) basis, so that he could spend more time with his family, particularly when his daughters Adele and Isobel were very young. This aspect was very nicely captured by Peter Taylor in his eulogy at Geoff’s funeral:

The fact that Geoff was able to make this choice, and still achieve as much as he did in his academic career, is both a testament to his enormous ability and a demonstrator to other academic staff that, far from being career-limiting, a healthy work-life balance can be career-enhancing.

The Australian Mathematics Society has decided to posthumously accredit Geoff as a Fellow of the Australian Mathematical Society (FAustMS). Furthermore, the Research School of Population Health (RSPH) has decided to honour Geoff’s contributions and to continue his legacy of mentoring and supporting students by establishing the Geoff Mercer Endowment. This will fund an annual award for postgraduate RSPH students to undertake an activity in pursuit of their academic goals, including travelling to a national or international conference.

Geoff is survived by his partner, Alex, his two daughters, Adele and Isobel, and by numerous past students and colleagues who have been positively affected by his life and work.