Washington: A new study has revealed that offshore islands actually amplify the power of tsunamis, increasing flooding on the mainland by up to 70 percent.
Costas Synolakis of the USC Viterbi School of Engineering, a member of the multinational team that conducted the research, said that offshore islands is where many fishing villages are located, in the belief that they will be protected from wind waves. Even Southern California residents believe that the Channel Islands and Catalina will protect them.
The research, which was inspired by a field survey of the impact of the 2010 tsunami on the Mentawai Islands off of Sumatra, showed that villages located in the shadow of small offshore islets suffered some of the strongest tsunami impacts, worse than villages located along open coasts.
The team designed a computer model that took into consideration various island slopes, beach slopes, water depths, distance between the island and the beach, and wavelength of the incoming tsunami and found that the offshore islands had actually contributed to-not diminished-the tsunami's impact.
The study was published in Proceedings of the Royal Society A.