The Inscriptions of Saint Sophia Cathedral Digitally Secured
The Saint Sophia Cathedral in Kyiv faces the risk of destruction due to Russia's war against Ukraine. Since January 2024, a research team from the University of Gothenburg has been working to document the cathedral's inscriptions for posterity.
The thousand-year-old inscriptions in Saint Sophia Cathedral, a UNESCO World Heritage Site, are an invaluable source for research on medieval languages, culture, and societal life. There are 8,000 inscriptions in a wide range of languages: Latin, Church Slavonic, Greek, Arabic, Hebrew, as well as Russian and Ukrainian.
They cover topics ranging from prayers to travelogues and agreements concerning land properties. This invaluable cultural heritage is threatened by Russia's war against Ukraine.
Now, a research project at the University of Gothenburg has created a digital research resource that makes the inscriptions accessible in both Ukrainian and English.
– Researchers in epigraphy, the branch of archaeology that interprets preserved inscriptions, previously needed special software and a powerful computer to handle this type of data. Now, it's possible to research the material via a regular web browser, says Jonathan Westin, Associate Professor in Conservation and Deputy Director of the Gothenburg Research Infrastructure for Digital Humanities (GRIDH).
– We have combined various open technologies into a single interface. It hasn't been possible to see the whole picture before, but now all the themes addressed in the inscriptions are revealed, and they become searchable for the first time.
The research resource will be presented at the Museum of World Culture in Gothenburg on 9 December, with representatives from Ukraine participating digitally.
– We believe it can open up new interdisciplinary research collaborations. Knowing who carved the inscriptions, in which language, and where in the room can provide clues about the church's social, symbolic, and practical uses, says Gunnar Almevik, Professor in Conservation and project leader.
Appeal for help
The project began when the National Museum in Ukraine reached out to the Swedish National Heritage Board with an appeal for help to preserve the threatened cultural heritage. The request was forwarded to Jonathan Westin and Gunnar Almevik at the University of Gothenburg. They had previously worked on collecting data, documenting, and building 3D models of the remnants of Otto Nordenskjöld's expedition in Antarctica.
They didn't hesitate, even though it meant being on-site in war-torn Ukraine to collect data and train local experts.
– During the first trip to Ukraine, we tested many different techniques. Quality was, of course, an important aspect, but so was the time required. Since such large areas need to be documented with extremely high resolution—to capture the trace of a needlepoint—time is a crucial factor, says Gunnar Almevik.
– The group in Ukraine that works continuously consists of an archaeologist, a conservator, and two architects. Together, we have improved workflows and supplemented equipment to produce both better quality and faster.
Three different techniques
The work of collecting and documenting the inscriptions has been ongoing since January 2024, using three different techniques:
- Laser scanning, to capture the entire monument and provide a sense of the space through 3D models. However, this method isn't sufficient to capture the inscriptions.
- Photogrammetry, measurements of three-dimensional positions, can show entire wall sections and how the various inscriptions relate to each other.
- To allow users to zoom in on the inscriptions, Reflectance Transformation Imaging (RTI) was used to create a kind of digital shadow model, using raking light and very high-resolution images.
– The problem with traditional documentation of inscriptions is that they aren't clearly visible with regular photographs. It requires raking light and very high resolution. We have taken thousands of high-resolution images per square meter, and it's a total of 3,000 square meters of wall surface with inscriptions, says Jonathan Westin.
Building expertise on-site
Working despite the ongoing full-scale war in Ukraine has meant that several methods they initially planned to use had to be discarded.
– When working with technology in a war-torn country, it needs to be cheap enough to leave behind or lose. We also weren't prepared for how tired we would be. Air raid alarms sounded both day and night, making it difficult to get proper sleep. But it feels very good to be able to contribute in a non-military way and help save a threatened cultural heritage. For the democratization of technology, it has also been important to build expertise on-site and develop software, says Jonathan Westin.
So far, about 25 percent of the surfaces with inscriptions have been documented. But gradually, the material will be supplemented – as long as the cathedral avoids direct attacks—thanks to a working group from Saint Sophia Cathedral being trained to continue the documentation work.
– Saint Sophia Cathedral is a cultural heritage for both Russia and Ukraine, but with very different interpretations of history. One might think that Russia would want to protect a shared cultural heritage, but so far, they have destroyed an incredible amount. UNESCO maintains a list that currently indicates 468 destroyed cultural sites, including the Cathedral in Odessa, which, like Saint Sophia Cathedral, is a World Heritage Site, says Gunnar Almevik.
Large amount of data
The collected data will be stored on servers in both Ukraine and Sweden to ensure accessibility. However, storing all the data presents a significant challenge for the researchers. Based on the data collected so far, the project could result in up to 3 petabytes (PB) – equivalent to 3,000,000,000,000,000 bytes of digital information.
This requires substantial server space, and merely storing the data for future research would, given the university's fees, cost over 7 million SEK per year.
– Currently, we're filling hard drive after hard drive, but I don't intend to discard any data until we're absolutely certain that the cathedral remains intact, says Jonathan Westin.
Preserving the inscriptions in Saint Sophia Cathedral offers valuable lessons and serves as a wake-up call for all future documentation of other threatened cultural heritage sites.
– There's an EU recommendation that all endangered cultural environments should be 3D-digitised by 2030. In Sweden alone, this means that thousands of cultural environments need to be documented. With this project, we're demonstrating how that work can be carried out. These are challenging issues we face when everything then needs to be stored digitally, says Jonathan Westin.
– There's a risk that the digitisation of cultural heritage becomes an end in itself and ultimately a digital junkyard. We must be able to assess the relevance of what's being documented and the quality required for different purposes, notes Gunnar Almevik.
Text: Johanna Hillgren
The project to collect data from Saint Sophia Cathedral, document it digitally, and train local expertise has received emergency funding from Formas, the Royal Swedish Academy of Letters, History and Antiquities, and the Swedish National Heritage Board.
In a new two-year project, researchers from the University of Gothenburg will continue to train staff in Ukraine and teach them how to create similar portals as the one for Saint Sophia Cathedral. The aim is to establish a "Center of Excellence."
