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Titel |
Volcanic hazard assessment for the Canary Islands (Spain) using extreme value theory |
VerfasserIn |
R. Sobradelo, J. Martí, A. T. Mendoza-Rosas, G. Gómez |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 11, no. 10 ; Nr. 11, no. 10 (2011-10-12), S.2741-2753 |
Datensatznummer |
250009729
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Publikation (Nr.) |
copernicus.org/nhess-11-2741-2011.pdf |
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Zusammenfassung |
The Canary Islands are an active volcanic region densely populated and
visited by several millions of tourists every year. Nearly twenty eruptions
have been reported through written chronicles in the last 600 yr, suggesting
that the probability of a new eruption in the near future is far from zero.
This shows the importance of assessing and monitoring the volcanic hazard of
the region in order to reduce and manage its potential volcanic risk, and
ultimately contribute to the design of appropriate preparedness plans. Hence,
the probabilistic analysis of the volcanic eruption time series for the
Canary Islands is an essential step for the assessment of volcanic hazard and
risk in the area. Such a series describes complex processes involving
different types of eruptions over different time scales. Here we propose a
statistical method for calculating the probabilities of future eruptions
which is most appropriate given the nature of the documented historical
eruptive data. We first characterize the eruptions by their magnitudes, and
then carry out a preliminary
analysis of the data to establish the requirements for the statistical
method. Past studies in eruptive time series used conventional statistics and
treated the series as an homogeneous process. In this paper, we will use a
method that accounts for the time-dependence of the series and includes rare
or extreme events, in the form of few data of large eruptions, since these
data require special methods of analysis. Hence, we will use a statistical
method from extreme value theory. In particular, we will apply a
non-homogeneous Poisson process to the historical eruptive data of the Canary
Islands to estimate the probability of having at least one volcanic event of
a magnitude greater than one in the upcoming years. This is done in three
steps: First, we analyze the historical eruptive series to assess
independence and homogeneity of the process. Second, we perform a Weibull
analysis of the distribution of repose time between successive eruptions.
Third, we analyze the non-homogeneous Poisson process with a generalized
Pareto distribution as the intensity function. |
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