Blog - Should we call ourselves digital archaeologists now? (Dan Hunt – CHERISH Project Investigator RCAHMW)

From Indiana Jones to Time Team, most people are familiar with the role of an archaeologist. We are often perceived as people that dig holes in order to find old things to stock museums, although I am sure there are one or two archaeologists out there that do run around tombs! While excavation does form a core part of the discipline there are many of us who rarely set foot anywhere near an excavation trench such as the aerial photographers, scientists, surveyors and finds experts. The multidisciplinary nature of archaeology epitomises the challenges we face when attempting to uncover and reconstruct the lives of past humans, a complex task that involves more than digging up pottery and gold. As with many sciences, archaeology is constantly evolving, embracing new technologies and techniques to not only improve our understanding of the past, but to bring it to life in present and preserve it for future generations. Moving with new technologies is also key to successfully managing our cultural heritage in the face of innumerable threats.

As a project looking at the threats of climate change on coastal heritage it was important that we adopted modern techniques in order to record, monitor and further our understanding of some of our most endangered sites around the coast. This is being achieved by using a whole host of different techniques, beautifully illustrated in our new ‘techniques’ graphic!

The CHERISH Techniques graphic showing the multidisciplinary nature of our work

The CHERISH Techniques graphic showing the multidisciplinary nature of our work

Much of this work involves the use of digital technologies such as drones, satellites and GPS, terrestrial laser scanning and aerial laser scanning to record archaeological sites as they currently appear. Using this technology, we can gather data and information for archaeological sites faster and in more detail than ever before. Recording in digital not only speeds up our work but makes it easier to carry out more complex analysis, reconstruct sites and publicise the results through forums such as social media. Working in this way is especially important during these strange times where the only way to access and explore archaeology for both us as archaeologists and the public is through our computer screens. But how is this possible, how can we ‘do’ archaeology from the comfort of our own homes using digital data and what has CHERISH been up to digitally since the project began? Being stuck inside has allowed some of us CHERISH folk to reflect on a few of the digital things that we have been up to over the last few years.

When I first arrived as a young archaeologist on CHERISH I was given the task of processing the LiDAR (lasers scanning carried out from a plane) data for six Welsh islands – a pretty daunting task for someone who had barely worked with 3D data before! This work involved the use of software to process the laser point data to get it prepared for interrogation for archaeological features. Different visualisations were produced to show 3D representations of the islands’ topography and archaeology using a clever piece of software known as the Real Visualisation Toolbox created by the Research Centre of the Slovenian Academy of Sciences and Arts. The different visualisations enabled us to see the islands as never before…

The different LiDAR visualisations that can be produced

The different LiDAR visualisations that can be produced

A few months working with the data and I was hooked. Searching for archaeology on the islands (which at this point I had never visited) became a new pastime. Countless archaeological features (some previously unknown) were mapped and recorded to produce new maps of all upstanding archaeology on each island, something that had not been done to such detail before. Bardsey Island (located at the tip of the Llyn Penisula) was by far the most impressive island mapped. An island coated in medieval and post-medieval field systems was revealed on the LiDAR, providing an insight into the farming past of the island. We were also able to take this further by looking at historical estate maps created for the Newborough estate in the 18th and 19th centuries for clues as to how the island was divided and farmed in the past. When overlaying the digitised maps on top of the LiDAR it became clear that some of the ploughed ridge and furrow visible on the LiDAR was in fact related to field systems visible on the historic mapping. However, much of the ploughing did not respect these field boundaries, enabling us to push their dates further back into the medieval and post-medieval period. The remarkable thing was that most of this work had been carried out from an office miles away from Bardsey – a true piece of digital archaeology.

Map showing all visible archaeological features on Bardsey Island including all of the ridge and furrow Map showing all visible archaeological features on Bardsey Island including all of the ridge and furrow shown in teal

The use of drones also forms a huge part of our digital survey work which is being carried out extensively in both Wales and Ireland. This is also an area of archaeology that, before arriving on CHERISH, I knew little about, but over the last few years it has in a way become my bread and butter. Drones (or UAVs) are steadily becoming a standardised tool used in the recording of archaeology and this is certainly the case on CHERISH where they have been deployed at almost all our sites. In our case, many of our sites are too dangerous to survey by any means other than using drones. High and crumbly cliffs are dangerous and best avoided by us archaeologists! However, these circumstances are where drones come into their own with their ability to record sites and eroding cliffs quickly and safely.

Clearly, visiting the sites is required to collect the initial data which is done by taking 100s of overlapping aerial photographs, however, most of the work is actually done from the comfort of the office (or bedroom now!). The main aim at the post-processing stage is to take all the photographs of an individual site and ‘stitch’ them together to create 3D data that can then be turned into numerous different outputs. This is achieved using software such as Agisoft Metashape which uses a technique known as photogrammetry to build 3D point cloud data by matching common points between the overlapping 2D photographs. From this process we are left with thousands or sometimes millions of points that represent the true shape and size of the monument (think what the site would look like if millions of small bouncy balls were placed all over the monument).

A 3D point cloud of Dinas Dinlle, Gwynedd

 A 3D point cloud of Dinas Dinlle, Gwynedd

We can use this point data to compare against previously collected data to carry out monitoring work. This is done in software such as CloudCompare which takes two point clouds, matches them up and then runs analysis to identify parts of a site that have metrically changed. Quantifying loss and identifying the weaker areas of sites is and important part of CHERISH’s work which will help in the management of sites against the complex risks climate change poses. This work has been done to good effect in Ireland where sites such as Dunbeg, County Kerry have suffered huge amounts of loss due to coastal erosion caused by increasing storminess in the region.

Huge loss at Dunbeg promontory fort, County Kerry
Huge loss at Dunbeg promontory fort, County Kerry

Another key aim of the project is to raise awareness of the archaeology of sites and the climate change risks they face. Drones (unsurprisingly!) also feature heavily in this aspect of our work where we use the drone data to produce digital 3D models to share online and use as outreach tools. We create these models by ‘meshing’ the points into a solid digital object which can then be shared online. As this is beyond my skill set we usually send off the data to expert 3D modellers (such as our friends at ThinkSee3D) to take our data and turn them into beautiful models that we can then upload to SketchFab for the public to have a look at and explore. During this period, we have taken the opportunity to produce ‘digital tours’ using annotations on SketchFab that highlight the visible (and sometimes hidden) archaeology as well as the types of climate change risks that they face. Have a look yourselves!

A SketchFab model of Caerfai Camp, Pembrokeshire
A SketchFab model of Caerfai Camp, Pembrokeshire

3D printing is also becoming a popular way of bringing digital data back into the real world to use as effective outreach tools. Before the lockdown we were keen to get a few of our sites printed to help us in our public engagement work. Thankfully, we were able to get a lovely print of Dinas Dinlle in Gwynedd which has been used instrumentally in describing the site and highlighting how it is being affected by coastal erosion. It has also proved to be a hit with school children across Wales! In the future we hope to take this work forward and to begin to develop site reconstructions and digital animations showing how sites previously appeared and how climate change is dramatically changing their appearance today, so watch this space…

Engaging with schools using drones and 3D models
Engaging with schools using drones and 3D models

So, coming back to the question ‘Should we call ourselves digital archaeologists now?’ I’m still unsure, but what is clear is that the digital ways of ‘doing’ archaeology are steadily becoming mainstream practices, especially in the archaeological survey world. We can never substitute fieldwork purely with remote and digital methods (and it must be said that I am greatly missing the fieldwork!) but who knows, perhaps the current lockdown situation will force us to adapt our methods and drive the digitisation of all of those beautiful maps and interesting historical documents that are tucked away in the dark corners of archives across the country. Digital archaeologists? perhaps not. But archaeology could become a whole lot more accessible to people as efforts are stepped up by archaeologists to continue to engage with people during this difficult time.

Dan Hunt – CHERISH Project Investigator