The VAPAH algorithm, developed here to facilitate this procedure calculates the probability of exceeding a given ash load for a site of interest and generates a hazard curve of annual probability of exceedance versus volcanic ash load (kg/m2).
For a given ash-to-cement ratio, the CFBC ash cement pastes has higher adsorption of the aliphatic SP than the PCC fly ash cement pastes.
Differences in the two weights were reportedly quite low for each comparison (a maximum of approximately 0.05 in the damage index for any given ash load), compared with the wide dispersion of the 'experts' responses (Maqsood et al., 2014, p101).
The areas enclosed in the 5%% probability contour for the tephra loading of 300 kg/m2 are 1004, 861, 965 and 1008 km2 for Spring, Summer, Autumn and Winter, respectively, suggesting that in Winter, and to some extent Spring, probabilities for exceeding the given ash thickness thresholds will be larger, and extend slightly towards the east in Summer.
For a given mass, voltage graphs show a steep decrease for accumulating fine ash, a moderate decrease for coarse ash and a gentle decrease for lapilli size tephra.
At longer time scales the footprint for a given threshold of ash loading might be expected to increase beyond the imposed 500 km limit (e.g. a Tambora 1815-style event; Sigurdsson and Carey 1989), and it is acknowledged that the distribution of ash at these longer timeframes (e.g. 10,000 years) in this PVAHA might be underestimated.
Through integrating the hazard module (presented here) with a damage module, the conditional probability of damage (or loss in dollars) for an exposed element could be calculated for a given threshold of volcanic ash load.
As a case study, we evaluate the potential impacts of ash for a given eruption scenario from Deception Island, one of the most active volcanoes in Antarctica.
In order to understand the impact from volcanic ash hazard for a given population, their location and their corresponding infrastructure must be taken into account.
For a given density, replacement of sand with fly ash resulted in higher strength.
For a given fibre content, compressive strength decreased with increasing pond ash content.
