Abstract
We propose a tectonic model associated with formation of the Akashi strait. The epicentral distribution of aftershocks and geodetic data show that the earthquake rupturing occurred not only along the Nojima Earthquake Fault and the Rokko Fault Zone striking NE-SW, but also occurred along the faults striking NW-SE in the Akashi strait. The earthquake surface ruptures striking NW-SE and NE-SW were also found in the northwestern end area of Awaji Island. The vertical displacements along these surface ruptures and the GPS data measured on the piers of Akashi strait bridge indicate that the central part of the Akashi strait subsided a few tens of cm among the 1995 Southern Hyogo Prefecture Earthquake. Based on these data, we show that the Akashi strait is a pulling-apart area between the right-lateral strike-slip faults of the Rokko Fault Zone and the Nojima Earthquake Fault, and that the Rokko-Awaji mountains are the areas showing the character of pressure ridge formed by pushing-up.
