Jahrringe, Lawinen und eine zerstörte Alphütte | Tree rings, avalanches and a destroyed cottage

In winter 1999, several buildings and cottages have been destroyed by a large snow avalanche in and around the village of Evolene (Valais, Switzerland). The age of the cottages destroyed by the event was supposed to be considerable, but the individual buildings were not dated. It was therefore the goal of this study to assess the age of one of the cottages with dendrochronological methods. The investigation was based on a local reference chronology composed of 19 reference larch trees (Larix decidua Mill.) from the Evolene region. The reference chronology was built through optical and statistical analyses of the samples as well as crossdating methods. The chronology extends back to 1642, with a minimum sample depth of three trees from 1654 and five trees from 1725. Through the comparison of the reference chronology with a piece of wood from the destroyed cottage, it was possible to date the outermost ring of the construction wood to AD 1693. The age of the dated construction wood suggests that the flow path of the 1999 avalanche was unusual and that it affected a sector that has, most probably, not suffered from similar events since at least 300 years.