Earthquake and War-Damaged Trees in Urban History: Non-Destructive Tree Diagnosis Using Sonic Tomography

Abstract

It has been a century since the Great Kanto earthquake and 78 years since WWII, both of which were catastrophic events in Japan’s history. Preserving memories of urban disasters is essential for preventing future tragedies, and while survivors’ testimonies hold great power, their numbers dwindle over time. However, trees which bear the scars of disaster can also serve as valuable storytellers. This study investigates earthquake and war-damaged trees, including 11 Gingo trees, 1 Chinquapin, and 1 Japanese nutmeg tree, located at the Yushima Seido Temple in Tokyo, and highlights their importance in preserving memories. The trees were measured using a sonic tomography tree internal diagnosis device, resulting in a total of 41 cross-sections that captured their conditions in images. The results indicated an ideal measurement method for trees located on slopes, as well as identifying a new type of classification shape for measurement cross-sections. The results of this research should primarily be of benefit to tree owners, but it is hoped that the benefits can also extend to a wider audience by increasing awareness about the significance of trees with unique urban historical narratives, aiding the preservation of urban green space, aiding in disaster preparedness, and promoting the role of such tress in peace education.