In 1961, the Vasa was raised in good condition from her brackish grave. After extensive treatment to stabilize and dry her timbers, in 1990 she was put on display at the Vasa Museum in Stockholm. Ten years later, museum conservators noticed that powdery salts were rapidly forming on her surfaces and that the wood in her holds was growing soft and acidic. In short, the Vasa was disintegrating.
The conservators called an emergency meeting with colleagues and chemists from Sweden, Denmark and Australia to seek solutions to a problem that threatens the Vasa and other famous finds including the Skuldelev Viking ships, the Bremen Cog, the Mary Rose and the Batavia.
Collaborators in Sweden and at Stanford have analyzed the chemistry of wood decay in the Vasa using a new technique - x-ray absorption spectroscopy. It employs high-energy synchrotron beams, produced when electrons accelerate around rings, to make chemical "fingerprints" that identify different oxidation states in a sample. Their findings, published in the Feb. 21 issue of Nature, may help conservators worldwide preserve wooden artifacts retrieved from the deep, many of which are displayed in museums.
The findings explain "the important role that scientists can have in keeping our historical treasures, which are indeed our connection to the old days," said researcher Farideh Jalilehvand of the Stanford Synchrotron Rad
Contact: Dawn Levy