Surface ruptures asso ciated with the 2000 Tottori-ken Seibu earthquake

Yuichiro Fusejima, Toshikazu Yoshioka, Kiyohide Mizuno, Shishikura Masanobu,
Ryusuke Imura, Taku Komatsubara and Toshinori Sasaki

We carried out detailed field surveys in the aftershock zone of the 2000 Tottori-ken Seibu earthquake to ascertain whether surface fault ruptures appeared in association with this earthquake (Fig. 1). As a result, we found fractures of the ground surface and destructions of artificial structures not attributable to landslides or liquefactions at many places in the epicentral area. These surface fractures and destructions were found along five NW-SE-trending lines in the area 6 km long and about 1 km wide (Fig. 2). The surface fractures strike N40±25°W and have left-lateral strike displacements of 10 cm or more (Fig. 3 , Fig. 4). Several to 40 cm left-lateral displacements toward N40±25°W were estimated from analysis of the destructions and deformations of artificial structures (Fig. 5 , Fig. 6). The direction and sense of the estimated displacement are consistent with the focal mechanism of this earthquake determined from seismological data (e.g., Iwata et al., 2001). From these facts, we have concluded that surface fault ruptures with a total length of about 6 km appeared in association with the 2000 Tottori-ken Seibu earthquake.