In Greek, the phrase “earth and water” symbolizes unconditional surrender, and derives from ancient times, when the Persian Empire demanded a symbolic offerings of soil and water from the cities they invaded¹. Indeed, the world offered “earth and water” to nature, when on Boxing Day 2004 the Sunda Trench ruptured, causing an earthquake of Magnitude 9.1, massive ground shaking in Indonesia, and triggered a tsunami that killed more than 225,000 people in 12 countries across the Indian Ocean. Just a few years later, Chile and Japan saw their coastlines severely damaged by the combined effects of earthquake ground shaking and tsunami inundation triggered by the 2010 M8.8 Maule Earthquake and 2011 M9.1 Tohoku earthquake, respectively. In these countries, stringent seismic building codes were not seen to necessarily be effective under the sequential hazards.

In this presentation, we will look at how our understanding of tsunami inundation and its interaction with buildings, has evolved in the 20 years since the Boxing Day Tsunami. We will explore our current ability to design/assess buildings for tsunami and their limitations. We will then look at how the seismic design of buildings can conflict with the provision of tsunami resistance. Finally, we will look at whether design for sequential earthquake and tsunami might look like. All this, in the hope that we will not need to fully surrender to nature, and offer “earth and water” in future earthquake-tsunami events.

Reference:

¹Rung, E. (2015). "The Language of the Achaemenid Imperial Diplomacy towards the Greeks: The Meaning of Earth and Water". Klio. 97 (2): 503–515. doi:10.1515/klio-2015-0035.