Abstract
Crustal deformations in the Chubu-Kanto region at and after the 2000 seismo-volcanic activity around the northern Izu islands were investigated using GEONET coordinate data of the Geographical Survey Institute. We found that three kinds of crustal deformations of different spatial patterns occurred successively. The first and the most prominent deformation was the one produced by the seismo-volcanic activity between Miyake and Kozu islands. The second kind deformation, characterized by southward displacement of the crustal block in the Chubu district, occurred after the peak of the first one. The third one is the on-going eastward displacement that became noticeable in 2001 along the coastal region of Aichi and Shizuoka Prefectures. It is shown that the second kind deformation was diffusive. We think the tem poral change in the displacement field might have been a viscoelastic response of the crust mantle system triggered by the extensive elastic deformation in the Kanto-Tokai region at the time of the northern Izu islands event.
