A Precarious Task
The road to recovery has been paved with many difficulties. The first issue the team faced was the damaged stonework of the cathedral. They realized that getting to the top of the vault could cause it to come tumbling down. However, observing it only from underneath would mean risking their lives due to the detritus.
Analyzing Stonework
This is why they have been partially unable to figure out how unstable the ruins of the cathedral actually are. What has helped is realizing that analyzing the color of the stonework could provide useful information. They shared that by observing the varying shades of the limestone blocks, the researchers could determine which temperature the blocks have been exposed to.