Volcanic disasters due to lava flow and the direction of countermeasures: based on risk management of lava flow during the 2018 Kilauea Volcano eruption
Takashi KOI and Yutaka GONDA
Lava flows from the 2018 Kilauea eruption caused a volcanic disaster on the island of Hawaii. This study summarizes lava flow characteristics, and reviews past volcanic disasters and countermeasures. Based on an interview survey on the 2018 Kilauea Volcano eruption, we discuss the direction of future countermeasures to be used against possible similar lava flows in Japan. Considering the high viscosity and low flow velocity, no significant damage to humans occurred or is expected, except for special cases. However, economic damage to buildings and other structures was significant. A large amount of basaltic lava erupted during the 2018 Kilauea event, causing damage to homes, infrastructure, and farmland. The main eruptive activity began with the fissure eruption on the Lower East Rift Zone, followed by the summit explosion and collapse of the Halema`uma`u crater in the Kilauea Caldera. Although no structural measures against lava flows such as flow direction control or cooling to reduce the flow velocity were taken, warning information was issued two days before the eruption and a lava‐flow hazard map was updated almost every day. To provide effective lava‐flow hazard maps, it is important to obtain updated data continuously, including the information on the volcano effusion rate and the latest topographical data during the eruption. These can be utilized in developing and maintaining a lava flow simulation model. The 2018 Kilauea eruption was the largest in the Hawaiian Islands in the last 200 years. Similarly, in Japan the possibility for volcanic eruptions with lava flow exists, even though no event has occurred in hundreds of years. Due to the steep and narrow topography in Japan, it would be difficult to implement structural measures effectively. Furthermore, an eruption involving a large amount of lava may isolate areas, cutting them off by slope failure associated with strong volcanic earthquakes. Therefore, risk management for volcanic lava flow events also necessitates formulating an evacuation plan that considers the occurrence of multiple hazard chains.
lava flow, volcanic disaster, countermeasure, disaster mitigation, the 2018 Kilauea Volcano eruption