General awareness of tsunami hazards was dramatically heightened by the global media attention given to the 2004 Indian Ocean disaster, and the subsequent deluge – what Sri Lankans have called a “golden wave” – of international tsunami relief and reconstruction aid that ensued (Telford, Cosgrave, and Houghton 2006; Gamburd, this volume). Before that unforgettable event, authors seem to have found the threat posed by tsunamis awkward to classify under the major categories of the natural hazards literature. A widely read textbook on the social causes and impacts of natural hazard vulnerability published just prior to the event (At Risk: Natural Hazards, People’s Vulnerability and Disasters, 2nd ed., by Wisner, Blaikie, Cannon, and Davis 2004) includes only four brief references to tsunami episodes scattered across three different chapters of the book. The problem is that tsunamis display “hybrid” characteristics. A tsunami is a wall of water, but unlike a conventional flood, it does not inundate lowland areas for a lengthy period of time. A tsunami has a sudden destructive impact, but unlike an earthquake it does not devastate large contiguous regions. A tsunami’s closest parallels are with volcanic eruptions, flash floods, and coastal storm surges, all of which permit a small degree of advanced warning and tend to affect narrowly-delineated geographical areas or ecological zones. But unlike tropical cyclones, tsunamis are not seasonal, and the extremely long intervals between tsunami disasters makes it difficult to sustain a collective concern about vulnerability (Wisner, et al. 2004: 107, 205, 246, 267-68, 275, 277).