caa a22 4500 467922640 CHVBK 20180406152921.0 cr unu---uuuuu 170328e20061101xx s 000 0 eng 10.1007/s00477-006-0041-x doi (NATIONALLICENCE)springer-10.1007/s00477-006-0041-x Statistical evaluation of compositional changes in volcanic gas chemistry: a case study [Elektronische Daten] [A. Buccianti, V. Pawlowsky-Glahn] The geochemical analysis of fumarolic gases collected at quiescent and active volcanic systems over time is one of the main tools to understand changes in the state of activity for surveillance and risk assessment. The continuous output of chemical species through fumarolic activity, which characterizes the inter-eruptive intervals, has also a major and general influence on the environment. The mobilization of chemical species due to weathering of volcanic rocks, or the input of gaseous components from fumarolic activity, results in some kind of modification of the environment affecting, in particular, water, soils, and the consequent growth of the plants present in these areas. In this paper, an investigation on the chemical composition of fumarolic gases collected at Vulcano island (Sicily, southern Italy) is performed, with the aim to discover how data changes during the monitored period of time, and to design a strategy for the environmental surveillance of volcanic systems taking into account the nature of the analyzed data. In order to summarize the contribution of all the components that can affect the chemical composition of volcanic gases, a multivariate statistical approach appears to be suitable. Since many of those methods assume independent observations, the possible presence of time-dependent structures should be carefully verified. In this framework, given the compositional nature of geochemical data, we have applied recent theoretical and practical developments in the field of compositional data analysis to work in the correct sample space and to isolate groups of parts responsible for significant changes in the gas chemistry. The proposed approach can be generalized to the investigation of complex environmental systems. Springer-Verlag, 2006 Compositional data analysis nationallicence Fluid geochemistry nationallicence Perturbation nationallicence Simplex nationallicence Hierarchical cluster analysis nationallicence Buccianti A. Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via G. La Pira 4, 50125, Firenze, Italy aut Pawlowsky-Glahn V. Dept. d'Informática i Matemàtica Aplicada, Universitat de Girona, Girona, Spain aut Stochastic Environmental Research and Risk Assessment Springer-Verlag 21/1(2006-11-01), 25-33 1436-3240 21:1<25 2006 21 477 https://doi.org/10.1007/s00477-006-0041-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00477-006-0041-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Buccianti A. Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via G. La Pira 4, 50125, Firenze, Italy aut NATIONALLICENCE 700 1- Pawlowsky-Glahn V. Dept. d'Informática i Matemàtica Aplicada, Universitat de Girona, Girona, Spain aut NATIONALLICENCE 773 0- Stochastic Environmental Research and Risk Assessment Springer-Verlag 21/1(2006-11-01), 25-33 1436-3240 21:1<25 2006 21 477 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer