Cluster Analysis of vents in monogenetic volcanic fields, Lunar Crater Volcanic Field (Nevada)
Abstract
Monogenetic volcanic fields pose a serious risk to human activities and settlements due to their high occurrence around the world and because of the type of eruptive activity that they exhibit. The need of adequate tools to better undertake volcanic hazard assessment for volcanic fields, especially from a spatial point of view, is of key importance at the time of mitigate such hazard. Among these tools, a better understanding of the spatial distribution of cones and vents and any structural/tectonical relationship are essential to understand the plumbing system of the field and thus help to predict the likelihood location of future eruptions. In this study we have developed a spatial methodology, which is the combination of various methodologies developed for volcanic textures and other clustering goals [1,2], to study the clustering of volcanic vents and their relation with structural features from satellite images. The methodology first involves the statistical identification and removal of spatial outliers using a predictive elliptical area [2] and the generation of randomly distributed points in the same predictive area. A comparison of the Near Neighbor Distance (NND) between the generated data and the data measured in a volcanic field is used to determine whether the vents are clustered or not. If the vents are clustered, a combination of hierarchical clustering and K-means [3] is then used to identify the clusters and their related vents. Results are then further constrained with the study of lineaments and other structural features that can be affected and related with the clusters. The methodology was tested in the Lunar Crater Volcanic Field, Nevada (USA) and successfully has helped to identify tectonically controlled lineaments from those that are resultant of geomorphological processes such the drainage control imposed by the cone clusters. Theoretical approaches has been developed before to constrain the plumbing of a volcanic field [4], however these are very sensitive to temporal and magma flux variation. An empirical approach such as the one proposed here seems to be a more robust technique. [1] Jerram et al., (1996) Contrib. to Min. and Petrol. 125: 60-74. [2] Chiasera and Cortés (2011) Journal of Volc. And Geotherm. Res. 207(3-4): 83-92. [3] Everitt et al., (2001) Cluster Analysis, Oxford University Press. [4] Baloga et al., (2007) Journal of Geophys. Res. 112, E03002, doi:10.1029/2005JE002652
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.V53C2849T
- Keywords:
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- 8178 TECTONOPHYSICS / Tectonics and magmatism;
- 8400 VOLCANOLOGY