Attempt to estimate the center of activity and scale of Quaternary volcanoes through topographic analysis

It is important to accumulate research examples on the spatial distribution of volcanic conduits and dikes under volcanic edifices that served as magma migration pathways, and eruptive volume of past activity, for risk assessment in volcanic disaster prevention. Particularly for volcanoes where the distribution of volcanic conduits and the eruptive volume of activity have not been clearly elucidated in detail, assessing their risk is difficult. Therefore, developing a quantitative and uniform assessing method applicable to each volcano is desirable. However, determining the distribution of volcanic conduits and dikes under volcanic edifices is challenging. Furthermore, estimating the eruptive volume of volcanic activity, requires detailed geological surveys, leading to insufficient estimates for some volcanoes.

The topography of a volcanic edifice is generally thought to reflect the location of magma intrusion associated with volcanic activity and its history (e.g., Nakamura, 1977). Therefore, we are developing a method to determine the predominant orientation of radial dikes under volcanic edifices and evaluate the long-term stability of central conduit locations using topographic analysis with GIS and 10m DEM (Nishiyama et al., 2023). Furthermore, we are attempting to develop a method to estimate the location of a center of activity and the eruptive volume of its activity using topographic data. The development of these topographic data-based evaluation methods is expected to provide useful objective baseline data for conducting detailed investigations on volcanoes that have not yet been studied in depth. This presentation introduces the content of our attempts using topographic analysis.

This study was funded by the Ministry of Economy, Trade and Industry (METI), Japan as part of its R&D supporting program for the geological disposal of high-level radioactive waste (JPJ007597).

[References] Nakamura, 1977, JVGR., 2, 1-16. Nishiyama et al., 2023, JSEG, 64(3), 98-111.