Abstract
Great Buddha of Kamakura is the second largest bronze Buddha in Japan built in around 1250AD. Kamakura locates at the high earthquake activity area in Japan. Although Great Buddha of Kamakura has repeatedly been attacked by several disasters as earthquake, rain storm or flood, the statue itself has still remained its original shape without serious damage until today. It is quite important for the Great Buddha of Kamakura to understand the vibration characteristics of the head because it relates to integrity of the connection between the body and the head. As a result of microtremor measurement at some points in the head, the vibration less than 10 Hz predominates at the head. Also it is cleared that the vibration over 20 Hz predominates at the body and the predominant frequency of the vibration related to the connection between the body and the head is lower frequency less than 10 Hz. The weight of the head has been estimated about 20 tons and it is remarkable that the vibration characteristics is significantly affected by change of the load about 155 kg at his jaw with removal of the inner small Buddha and other deposits. It suggests that the welding connection moves with a certain level of degrees of freedom but the head vibrates as a unit. Therefore, it pointed out the necessity to consider carefully the connecting situation at each portion in the head.
