Climate and soil experts investigated whether drought is contributing to damage at medieval churches in Oostum and Den Ham, northwest of the city of Groningen. The study was commissioned by the province of Groningen and Stichting Oude Groninger Kerken after cracks at the church in Oostum continued to worsen despite there being no major earthquakes since earlier repairs in 2016.

The researchers found that the subsurface is sensitive to shrinking and swelling: peat can oxidize and compact as groundwater falls, while clay shrinks during drought and expands when wet. They said drought may be contributing to the church’s movement and cracking alongside other factors, including earthquakes, traffic and environmental changes. The study is exploratory and requires longer-term research before firm conclusions can be drawn. Possible measures include improving water management and digging pits around churches to allow water to infiltrate the soil gradually.