Abstract On 17 June 1996, Ruapehu volcano, New Zealand, produced a sustained andesitic
sub-Plinian eruption, which generated a narrow tephra-fall deposit extending more than 200 …

An improved empirical method for the plotting of field data and the calculation of tephra fall
volumes is presented. The widely used “area” plots of ln (thickness) against ln (isopach …

Many tephra fall deposits exhibit simple exponential decay of thickness and grainsize
(Tborarinsson, 1954). This observation has been proposed as the basis for determining the …

The calculation of volumes of fallout tephra layers is difficult because of the nonlinear
dependence of thickness on area and because of the extrapolations required at the vent and …

Well-preserved tephra fall deposits display thickness variations which are more complex
than simple exponential thinning. On plots of log thickness against square root of area …

The uncertainties associated with tephra thickness measurements are calculated and
implications for volume estimates are presented. Statistical methods are used to analyse the …

A model for sedimentation from turbulent suspensions predicts that tephra concentration
decreases exponentially with time in an ascending volcanic column and in the overlying …

Volume determination of tephra deposits is necessary for the assessment of the dynamics
and hazards of explosive volcanoes. Several methods have been proposed during the past …

A simple method is presented to calculate the minimum volume of an exponentially-thinning
fall deposit for which only one isopach is available. This method exploits the fact that the …

The Weibull distribution between volume and square root of isopach area has been recently
introduced for determining volume of tephra deposits, which is crucial to the assessment of …