Blast from the Past VI: Mapping an Underground Roman City

Before finishing the series of my past adventures on the field, I will share one more experience, which followed the other aforementioned excavations of the 2017 field season. Before limiting the rest of the autumn for shorter excavations, I still had time for one more field trip and I spent it no further than in Italy. It was my first time in the country and the first time to research classical civilizations. However, this time there were no trowels and shovels, as our main instrument was a ground-penetrating radar.

Carlos working while I'm resting under the only tree on the field.

Ground-penetrating radar (GPR) is one of the main geophysical methods used in archaeology to discover buried structures. The device emits electromagnetic energy into the ground and tracks signals reflected from buried objects and boundaries between materials of different permittivities. While the data can be already monitored on the field, it can also be further processed afterwards and turned into very informative maps of what lays directly underground.

In Italy, I took part in a field school organized by the Apolline Project in a Roman town called Aeclanum. While the site had already been excavated and turned into an archaeological park, there was still much hidden beneath the surface and each year groups of students came from all over the world to do their part in excavations and field schools of various topics. The task of our small GPR team was not only to learn the basics of the GPR, but also to pinpoint sites for future excavations.

Starting from the very first day, I knew I had arrived to the right place and was excited not only to work on the field, but also to process the data afterwards. The work on the field was fairly simple - basically we placed a grid on the field and walked systematically back and forth with the machine. The only tedious factor was the weather, as the field school was organized during the infamous "Lucifer" heat wave, due to which the temperature rose over 40 C each day. However, we tried our best to adjust our working hours to the conditions and managed to keep up the pace.

Some initial results from Aeclanum.

While gathering data on the field was fairly entertaining even with the constant heat, the most interesting part was to actually see the results of our hard work. With each line we walked, more information was availed and eventually we could see the whole area before our eyes - walls, streets and even a whole forum with podiums of some sort. Without touching a shovel, we knew what was beneath us and this all was important information for those who were planning excavations for the next years.

These two weeks gave me a lasting impact and a strong interest in geophysical methods. After I returned to Finland, I decided to write my BA on the topic and ended up borrowing the GPR of our faculty for my own research at a dugout in Hanko. I even traveled to the UK to take part in a seminar of archaeological geophysics. While my original enthusiasm never faded, the realities of the lack of teaching and the difficulties in finding instruments for research have stopped me from further advancing my own learning.

But who knows, maybe one day I get to return to the world of geophysics! Meanwhile I have my hands busy with other assignments, of which I will write in the next posts!