Preservation from Rockfall of the Engraved Wall in the Fugoppe Cave, Hokkaido, Japan

The Fugoppe Cave, Hokkaido, Japan is known as a unique engraved walls designated as National Cultural Heritage formed in ca. 1 600 yr B.P. The Fugoppe Cave is composed of Neogene tuffaceous sandstones and has been weathered to easily fall and be spalled off along many cracks. Hence, according to the advices of the Committee for the Preservation of the Fugoppe Cave (Chairman: Masami Fukuda), we were making the photographic images of the three walls, one of which were divided into 116 grids of 50 cm long, and doing geological and geotechnical researching for each wall, such as evaluation of rockfall susceptibility of the walls.