Development of the very long range muographic imaging technique to explore the internal structure of an erupting volcano, Shinmoe-dake, Japan

Abstract

Abstract. Muography offers us a tool to observe hazardous erupting volcanoes remotely. However, practical muographic observations of volcanoes from a distance are difficult; therefore, various observations have been performed in the vicinity (< 1.5 km) of volcano peaks to suppress background noise and enhance images. In this study, we created a muographic image directly beneath the caldera floor of the erupting Shinmoe-dake volcano in Japan by locating our muography telescope 5 km from the peak. Shinmoe-dake volcano began to erupt on 19 January 2011, and in less than one month, the ejected lava almost completely filled the caldera and completely changed the topography of the caldera floor. The resultant image shows a low-density region underneath the western part of the newly created caldera floor, which indicates the existence of a void there. After the volcano became less active in February 2011, infrequent eruptions might have left a void beneath the caldera floor, which may trigger a collapse in the future. We anticipate that our novel muography will be a practical tool for monitoring and predicting eruption sequences in the near future.

Radiography with cosmic-ray and compact accelerator muons; Exploring inner-structure of large-scale objects and landforms

“…Asama 13,18) and Mt. Shinmoe-dake, 22) a change in an internal structure of the top region of the volcano was detected before and after eruption (in 2004 for Mt. Asama and in 2011 for Mt.…”

“…Following the initial proposals, 12,13) IA type of CRM radiography has been applied to various volcanos in Japan 15–22) and in the world. 23) So far the following achievements have been obtained, mainly by the group of the Earthquake Research Institute, the University of Tokyo led by H.K.M.…”

“…The back ground removal possibilities have been discussed in the Shinmoe-dake studies, 22) while an air contribution problem for the Mt. Fuji are now under investigation in the Yamanashi U. research group.…”