Tsunamis are natural hazards that have caused massive destruction and loss of life in coastal areas worldwide for centuries. Major programs promoting tsunami safety, however, date from the early 20th century and have received far greater emphasis following two major events in the opening decade of the 21st century: the Indian Ocean Tsunami of December 26, 2004, and the Great East Japan Earthquake and Tsunami of March 11, 2011. In the aftermath of these catastrophic disasters, warning systems and the technologies associated with them have expanded from a concentration in the Pacific Ocean to other regions with significant tsunami vulnerability. Preparedness and hazard mitigation programs, once the province of wealthier nations, are now being shared with developing countries. While warning systems and tsunami mapping and modeling are basic tools in promoting tsunami safety, there are a number of strategies that are essential in protecting lives and property in major tsunami events. Preparedness strategies consist of tsunami awareness and education and actions that promote response readiness. These strategies should provide an understanding of how tsunamis occur, where they occur, how to respond to warnings or natural signs that a tsunami may occur, and what locations are safe for evacuation. Hazard mitigation strategies are designed to reduce the likelihood that coastal populations will be impacted by a tsunami, typically through engineered structures or removing communities from known tsunami inundation zones. They include natural or constructed high ground for evacuation, structures for vertical evacuation (either single purpose structures specifically for tsunami evacuation or existing buildings that are resistant to tsunami forces), seawalls, breakwaters, forest barriers, and tsunami river gates. Coastal jurisdictions may also use land-use planning ordinances or coastal zoning to restrict development in areas of significant risk of tsunami inundation. The relative efficacy of these strategies and locations where they have been implemented will be addressed, as will the issues and challenges regarding their implementation.
James Goltz and Katsuya Yamori
Fatalism about natural disasters hinders action to prepare for those disasters, and overcoming this fatalism is one key element to preparing people for these disasters. Research by Bostrom and colleagues shows that failure to act often reflects gaps and misconceptions in citizen’s mental models of disasters. Research by McClure and colleagues shows that fatalistic attitudes reflect people’s attributing damage to uncontrollable natural causes rather than controllable human actions, such as preparation. Research shows which precise features of risk communications lead people to see damage as preventable and to attribute damage to controllable human actions. Messages that enhance the accuracy of mental models of disasters by including human factors recognized by experts lead to increased preparedness. Effective messages also communicate that major damage in disasters is often distinctive and reflects controllable causes. These messages underpin causal judgments that reduce fatalism and enhance preparation. Many of these messages are not only beneficial but also newsworthy. Messages that are logically equivalent but are differently framed have varying effects on risk judgments and preparedness. The causes of harm in disasters are often contested, because they often imply human responsibility for the outcomes and entail significant cost.