Have a listen to an interview I did for the Naked Scientists, a BBC Radio Cambridgeshire podcast about our recent Nature Ecology and Evolution paper. This piece featured on BBC Radio and ABC Radio National Australia.
(Ignore the transcript below, I think it was generated automatically and didn’t like my accent!)
This time last year I embarked on a research expedition to the Arctic. I was working with Dr. Margaret McCaul in the National Centre for Sensor Research (NCSR) at Dublin City University (DCU) assisting her with the development of a cost-effective nutrient sensor for the marine environment. Thanks to all of Margaret’s hard work and the support of our supervisor Prof. Dermot Diamond, we were able to take the sensor to Ny-Ålesund, Svalbard for testing in extreme conditions.
Ny-Ålesund is the northernmost community in the world at 79°N and it was a very special opportunity to be allowed to work in this pristine environment. The area is a consortium of research stations from 9 different countries engaged in Arctic research. There are of course many visitors from countries without research stations, such as ourselves from Ireland. We were lucky to be invited to work at the Italian station through a collaboration with Consiglio Nazionale delle Ricerche (CNR). Here, we worked hard alongside some excellent researchers, and we had our fair share of fun too!
The sensor deployment was a big success and showed the system to be rigorous in the face of harsh conditions. This of course was all down to Margaret and her team back in the NCSR. I must also mention the excellent staff at King’s Bay AS, the support crew for Ny-Ålesund, who ensured everything went as smoothly as possible. The trip was one of the best experiences of my life so far, and hopefully it was the first of many trips to the Arctic for me.
I can certainly think of several important biogeochemical questions that I would like to answer in the future…
When I first began work on soil samples from the Italian Alps I didn’t realise the significance of the question that I was endeavouring to answer. Whilst determining the exact route taken by Hannibal of Carthage across the Alps to invade Italy in 218 BC won’t exactly change the way we live our lives, it is certainly of great interest to archaeologists, historians, and anyone with an interest in history. In fact, I believe people are always captivated by others who take great risks and embark on seemingly impossible journeys. Just how they manage to succeed in these extreme feats grasps the attention of everyone with an inquisitive mind.
Prof. Bill Mahaney of York University, Toronto certainly knew of the importance of this work as he had been fascinated by Hannibal’s great endeavour for many years. After thorough examination of the relevant literature from both ancient and modern historians, he was impressed by Sir Gavin De Beer’s inclusion of environmental factors in his suggestion of a particular passage through the Col De La Traversette. Prof. Mahaney had to see this for himself and so travelled the route and applied his expertise in geological techniques to investigate whether this really could be Hannibal’s chosen path. The results of this historical and geological analysis are presented in part 1 of our recent publication in Archaeometry.
Knowing that this evidence was not sufficient, Prof. Mahaney contacted his colleagues around the world to provide further analytical approaches using their own expertise. The project had now become a major multidisciplinary investigation involving researchers from Canada, Ireland, the USA, Estonia, Portugal, the UK, and France. My supervisor in Dublin City University, Dr. Brian Kelleher, was contacted to enquire about conducting chemical analysis of soils along the route. When an army of 30,000 troops, 15,000 horses, and 37 elephants travels through an area they are sure to leave some mark. In this case it was faecal biomarkers, chemical compounds in excrement that remain in the environment for 1000s of years.
Along the route there is a large body of water in the Guil Valley, an obvious place to rest for any traveller and perfect for a large army. Whilst sampling soil from an adjacent mire it was discovered that a layer of the soil was noticeably ‘churned-up’. The soil was disturbed in such a way as to suggest that there must have been significant activity at this point in history. Radiocarbon dating of this layer placed it spectacularly close to the date of Hannibal’s epic journey. Soil samples from this spot and other parts of the valley were analysed by myself and colleagues here in the OGRe lab in DCU, Dr. Shane O’Reilly and Dr. Brian Murphy. We detected significant levels of faecal sterols and bile acids, compounds produced during digestion, in this churned-up layer but not in any other location.
These chemical biomarkers are rarely present naturally in the environment and high concentrations such as those observed here are almost certainly due to faecal deposition. Microbiologists at Queen’s University, Belfast isolated gut bacteria from this soil as well, supporting the evidence of faecal deposition. These results are published in part 2 of our paper in the journal Archaeometry.
So far, along a route which matches well with historical accounts, we have identified a layer of disturbed soil with significantly increased levels of animal and/or human faeces which dates to the same time period of Hannibal’s crossing of the Alps. The media response to these findings has been brilliant, beginning with excellent articles written in The Guardian and The Irish Times. Since then the story has been covered by the BBC, CNN, The Huffington Post, Science Magazine and many others. In the past few days over 100 articles have emerged from publications across the globe, an overwhelming response. Whilst some media reports have claimed the age-old question has been answered, this is certainly not case closed. It is, however, very compelling evidence which requires further investigation to solve this mystery once and for all.
Hopefully some archaeological work in the near future will uncover items left by Hannibal’s army. Maybe there will be skeletal remains of soldiers, horses, or even elephants buried along the route. Until then, I am happy to have helped pave the way for this future research which may prove once and for all that this was the path chosen by Hannibal to conduct one of the most daring military journeys in history.
All going well, this day two weeks I will be on board the Marine Institute of Ireland‘s research vessel, the RV Celtic Explorer, on the hunt for the extent of the British-Irish Ice Sheet (BIIS).
The RV Celtic Explorer (© David Brannigan-Oceansport) and the Celtic Sea (© Google Earth)
In cooperation with NUI Maynooth under the 3U Partnership, the Organic Geochemistry Research (OGRe) team from Dublin City University will be joining Dr. Stephen McCarron taking sediment samples in the Celtic Sea south of the island of Ireland. Our aim will be to carry out sampling and preliminary analysis whilst on the cruise, and then to perform further detailed geochemical analysis of the samples back in our laboratory. We will be sub sampling sediment from vibrocores and obtaining grab samples from the sea bed. Pore water from these sediments will be taken onboard and some spectrophotometric nutrient analyses will be carried out in situ with remaining water samples frozen and transported back to DCU. We also be measuring temperature and salinity as well as sampling the water column using the Explorer’s Rosette sampler. Our final task will be to use plankton nets to determine the macrobiotic species present in the region at this time.
The team is also made up of researchers from the Geological Survey of Ireland (GSI), Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), British Geological Survey (BGS), University of Durham, and Queens University Belfast (QUB). Together we hope to uncover some exciting information about the BIIS and also the relatively understudied area of the Celtic Sea.
More information can be found on the expedition website.
Sean F Jordan 