An objective method for smoothing palaeomagnetic data

This paper describes a new method of smoothing noisy data, such as palaeomagnetic directions, in which the optimum degree of smoothing is determined objectively from the internal evidence of the data alone. As well as providing a best-fitting smooth curve, the method indicates, by means of confidence limits, which oscillations or fluctuations in the fitted curve are real. The procedure, which is illustrated by an analysis of palaeomagnetic declination directions from Lake Windermere, has potential applications throughout the Earth Sciences. It may be used in any investigation requiring the estimation of a smooth function from noisy data, provided certain basic assumptions are reasonably satisfied.