When an earthquake occurs, various seismic motions occur such as wiggle shaking and slow shaking. The time associated with a single shake is called a “period,” a sharp shake with a short cycle is referred to as a "short-period seismic motion," and a slow and large fluctuation with a long period is referred to as a “long-period ground motion.” High-rise buildings commonly resonate with long-period ground motion; especially high-rise floors experience significant sway motion*. In Japan, espe...

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The “Symposium on Risk, Resilience, and Disaster Management,” hosted by the Global Risk Forum (GRF), was held in Davos, Switzerland, on November 23, 2018. A total of 20 people participated, including representatives from UNESCO, the Joint Research Centre of the European Commission, as well as disaster management experts from various countries, and members of the media. Prof. Fumihiko Imamura, the Director of IRIDeS, was also invited to the symposium, along with other IRIDeS faculty members. H...

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Discovery of an exception to rare movements of active faults Active faults are faults that have experienced repeated ruptures in the past and are likely to cause earthquakes in the future. The cause of intraplate earthquakes shallow in the Earth’s crust is an abrupt rupture of such active faults. The number of active faults identified on the islands of Japan is approximately 2,000. Naturally, large intraplate earthquakes occur once per a few years somewhere in Japan. The frequency of earthqu...

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On October 21, 2018, Assistant Professor Kazuya Sugiyasu of IRIDeS and his research group jointly conducted a disaster drill for potential earthquakes and tsunamis in Tairausuiso District (hereinafter Usuiso District) of the city of Iwaki, Fukushima Prefecture. I, a PR staff from IRIDeS, also attended this drill. The below is an account of my experience at the drill exercises. Usuiso District Usuiso District faces the sea. During the 2011 Great East Japan Earthquake and Tsunami, a 8.51 m ta...

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A M7.5 earthquake occurred on September 28, 2018, at 6:02 pm (7:02 pm Japan time) on the Indonesian island of Sulawesi. A significant amount of damage was caused by the earthquake, subsequent tsunami, liquefaction, and landslides. On October 4–6, Prof. Fumihiko Imamura (Tsunami Engineering) of IRIDeS conducted the first field survey to investigate the damage caused by the tsunami in and around the major city of Palu in collaboration with other researchers and government officials in Indonesia...

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