Title: Model based functional clustering of varved lake sediments
Authors: Per Arnqvist - Umea University (Sweden) [presenting]
Sara Sjostedt de Luna - Umea University (Sweden)
Abstract: Climate and environmental changes are today widely discussed, and in particular the impact of human activity. To understand variations in past climate over longer time periods, historical documents, year rings from trees, ice cores from glaciers as well as lake and sea sediments are being used. We introduce a model based functional cluster analysis, giving us possibility to use both the functional form and covariates in our analysis. It also allows us to model the dependency of the chosen basis coefficients and the covariates. We allow for different covariance structure within each cluster and give suggestions on how to determine how many clusters to use. In particular we analyze varved sediment from lake Kassjon (N Sweden) which cover more than 6400 years.