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[HCG24-01] Examination of modeling of Quaternary volcanic dike distribution and evaluation of central conduit stability by contour shape analysis
Keywords:Quaternary volcano, Central conduitCentral conduit, Dike, GIS: Geographic Information System, Contour polygons
The topography of the volcanic mountain body is thought to reflect the actual distribution range of the dike [1]. Based on this idea, we examined the modeling of the dike distribution and the evaluation of the central conduit stability focused on the shape of the contour lines.
In this study, we drew the line with the maximum distance (long axis) in the contour distribution of each elevation and aggregated the orientation data, in addition to the data obtained from the analysis of Nishiyama et al. (2021) [2]. Moreover, we calculated the topographic parameter of each volcano, using the area data of the area enclosed by the contour lines (contour polygons).
As a result, we found that the orientation of the long axis of the contour polygons of volcanic bodies shows the orientation trend in each volcano. The orientation of the line connecting the centroid of many volcanoes is consistent with that of the line connecting the centroid, which is roughly consistent with the direction of σ1 around the volcanoes. In general, dikes are characterized by extension in the direction of the maximum compression axis [3], and our topographic analysis results are consistent with this. As for the topographic parameters of each volcano using the area of contour polygons, the result suggests that it is possible to distinguish between volcanoes classified as central conduit stable and unstable by Takahashi (1994) [4]. Therefore, the topographic analysis is expected to be used to evaluate the stability of central conduit even for volcanoes whose activity history is not yet known.
In the future, we will develop an evaluation method based on the above topographic features, and establish a method for evaluating the central conduit stability and modeling the distribution of dikes by topographic analysis.
This study was funded by the Ministry of Economy, Trade and Industry (METI), Japan as part of its R&D supporting program titled “Establishment of Advanced Technology for Evaluating the Long-term Geosphere Stability on Geological Disposal Project of Radioactive Waste (JPJ007597) (Fiscal Years 2020-2021)”.
[1] Nakamura (1977). Journal of Volcanology and Geothermal Research, 2, 1-16.
[2] Nishiyama et al. (2021). Japan Society of Engineering Geology (Abstract), 88, 169-170.
[3] Nakamura (1969). Volcanological Society of Japan, 14, 8-20.
[4] Takahashi (1994). Volcanological Society of Japan, 39, 191-206.
In this study, we drew the line with the maximum distance (long axis) in the contour distribution of each elevation and aggregated the orientation data, in addition to the data obtained from the analysis of Nishiyama et al. (2021) [2]. Moreover, we calculated the topographic parameter of each volcano, using the area data of the area enclosed by the contour lines (contour polygons).
As a result, we found that the orientation of the long axis of the contour polygons of volcanic bodies shows the orientation trend in each volcano. The orientation of the line connecting the centroid of many volcanoes is consistent with that of the line connecting the centroid, which is roughly consistent with the direction of σ1 around the volcanoes. In general, dikes are characterized by extension in the direction of the maximum compression axis [3], and our topographic analysis results are consistent with this. As for the topographic parameters of each volcano using the area of contour polygons, the result suggests that it is possible to distinguish between volcanoes classified as central conduit stable and unstable by Takahashi (1994) [4]. Therefore, the topographic analysis is expected to be used to evaluate the stability of central conduit even for volcanoes whose activity history is not yet known.
In the future, we will develop an evaluation method based on the above topographic features, and establish a method for evaluating the central conduit stability and modeling the distribution of dikes by topographic analysis.
This study was funded by the Ministry of Economy, Trade and Industry (METI), Japan as part of its R&D supporting program titled “Establishment of Advanced Technology for Evaluating the Long-term Geosphere Stability on Geological Disposal Project of Radioactive Waste (JPJ007597) (Fiscal Years 2020-2021)”.
[1] Nakamura (1977). Journal of Volcanology and Geothermal Research, 2, 1-16.
[2] Nishiyama et al. (2021). Japan Society of Engineering Geology (Abstract), 88, 169-170.
[3] Nakamura (1969). Volcanological Society of Japan, 14, 8-20.
[4] Takahashi (1994). Volcanological Society of Japan, 39, 191-206.