Feb 04 2021 Read 18066 Times Author: Dr Claudia Mondelli on behalf of Institut Laue-Langevin Free to read Unlock When wooden objects sink to the bottom of the sea, they are generally served an extended lifespan. On land, wooden artefacts such as shipwrecks may be destroyed through rotting, animals, or human action, but marine environments can prevent the biological, chemical, and mechanical changes that would cause an object to decay – preserving a rare time capsule to our past. However, when an ancient shipwreck is pulled from the water, the process of acidification can start and they can begin to crumble. In addition to structural changes from the drying of the wood – causing shrinking and cracking – iron present in features such as nails, combined with sulphur from bacteria, creates the compound ‘iron sulphide’. This material, dormant under water, can develop into destructive sulphuric acid when met with oxygen above ground. This acidification ‘infection’ of the wood can spread and make the entire structure crumble within days, risking the loss of thousands of years of human history. One of the world’s most famous shipwrecks, the 400-year old Vasa ship in Stockholm, was partially eaten by sulphuric acid in the early 2000s due to the ferociousness of the process.