1983 年三宅島噴火前後の写真測量から得られる地形変化と水準測量による上下変動

概要

論文の詳細を見る
The Geographical Survey Institute revised the 1 : 5, 000 scale volcanic base maps of Miyake-jima because remarkable geomorphological changes were associated with the 1983 eruption of the Miyake-jima volcano. Leveling along the route skirting the coast of the island was also carried out after the eruption. The geomorphological changes can be revealed by comparing the maps with the ones published in 1981. The outflow consisting mainly of lava in the west of eruption fissures is estimated to be (7.0±2.0)×10^<-3> km^3 in volume. There are many elevation spots distributed on the side of the mountain. There is no recognizable change in their elevation exceeding the measurement error. However, appreciable ground subsidence is found around a new crater near the Shinmyo pond located in the southern part of the island. A comparison of pre- and post-eruption surveys shows that relative uplift took place in the northeastern and southwestern parts of the coast and subsidence in the northwestern and southeastern parts. The peak to peak displacement is about 24 cm. An almost opposite trend of deformation with much smaller amount is recognized for the period of several years befor the eruption.
特定非営利活動法人日本火山学会の論文
1984-12-28