Mechanism of Tsunami Fires after the Great East Japan Earthquake 2011 and Evacuation from the Tsunami Fires

The tsunami after the Great East Japan Earthquake on 11 March 2011produced a huge impact under which various oil tanks at ports and industrial complex and gas cylinders at homes, automobiles, etc. were damaged and caused hazardous materials such as gas and gasoline in those oil tanks, gas cylinders and fuel tanks to leak. In these situations, sparks from metals which collided each other by tsunami and through other scenarios may have ignited leaked combustible gases and gasoline to become fires. These fires spread to combustible materials in and from broken houses, automobiles etc. near around. Ignited broken houses, automobiles, fishing boats and other combustible materials floating with tsunami waves spread fires to accumulated combustible materials swept away by tsunami from broken houses and landed floating housesat stagnated points near banks and hillsides. There were also some cases that leaked gases from gas-cylinders and leaked gasoline from fuel tanks of automobiles under the accumulated materials have caused fires according to witnesses of residents. Leaked oil from tanks may have contributed to the combustion in these circumstances. In these ways, fires broke out at various places throughout the tsunami affected region and some escalated to large-scale urban fires especially in wooden urban areas. Many of the people that had been evacuated from the tsunami-affected zone to tsunami refuge buildings had once again to be evacuated to avoid the spreading, escalating fires. The fire spread area was wide, and it is commonly recognized among researchers of universities and research institutes that cooperation is necessary to share information of earthquake fires and tsunami fires. This paper is mainly based on an interim report of this kind of cooperation organized by the Japan Association for Fire Science and Engineering (2011).