The Great East Japan Earthquake with a moment magnitude 9.0 occurred on March 11, 2011 and shook almost the entire Japan. There are many abandoned lignite mines in the close vicinity of the epicentral areas such as Miyagi and Iwate prefectures and many sinkholes occurred following the earthquake. There are also reports on the delayed occurrence of numerous sinkholes in the same areas. In addition, some collapses and subsidence occurred above abandoned underground quarries in Oya town of Utsunomiya City. The authors investigated damaged areas soon after the earthquake and they present their investigation results. They also discuss their implications in short and long-term performance of abandoned mines and quarries possible counter-measures against collapses in this article.
This paper presents damage of bridges during the 2011 Great East Japan earthquake. Since the bridges in the north Miyagi-ken and south Iwate-ken suffered extensive damage in the 1978 Miyagi-ken-oki earthquake, damage of bridges in the 2011 Great East Japan earthquake is evaluated in comparison with the damage in the 1978 Miyagi-ken-oki earthquake so that effect of the recent progress of seismic design can be evaluated. Tsunami-induced damage was extensive for bridges along the Pacific Coast. Typical feature of tsunami-induced damage is presented based on a field investigation and video movies.