Natural Hazards and Earth System Science www.nat-hazards-earth-syst-sci.net 1561-8633 1684-9981 10 4 2010 10.5194/nhess-10-641-2010 http://www.nat-hazards-earth-syst-sci.net/10/641/2010/ http://www.nat-hazards-earth-syst-sci.net/10/641/2010/nhess-10-641-2010.html http://www.nat-hazards-earth-syst-sci.net/10/641/2010/nhess-10-641-2010.pdf 641 646 2010-04-06 The challenge of installing a tsunami early warning system in the vicinity of the Sunda Arc, Indonesia J. Lauterjung lau@gfz-potsdam.de U. Münch A. Rudloff Deutsches GeoForschungsZentrum GFZ, Telegrafenberg, 14473 Potsdam, Germany Indonesia is located along the most prominent active continental margin in the Indian Ocean, the so-called Sunda Arc and, therefore, is one of the most threatened regions of the world in terms of natural hazards such as earthquakes, volcanoes, and tsunamis. On 26 December 2004 the third largest earthquake ever instrumentally recorded (magnitude 9.3, Stein and Okal, 2005) occurred off-shore northern Sumatra and triggered a mega-tsunami affecting the whole Indian Ocean. Almost a quarter of a million people were killed, as the region was not prepared either in terms of early-warning or in terms of disaster response. <br><br> In order to be able to provide, in future, a fast and reliable warning procedure for the population, Germany, immediately after the catastrophe, offered during the UN World Conference on Disaster Reduction in Kobe, Hyogo/Japan in January 2005 technical support for the development and installation of a tsunami early warning system for the Indian Ocean in addition to assistance in capacity building in particular for local communities. This offer was accepted by Indonesia but also by other countries like Sri Lanka, the Maldives and some East-African countries. Anyhow the main focus of our activities has been carried out in Indonesia as the main source of tsunami threat for the entire Indian Ocean. Challenging for the technical concept of this warning system are the extremely short warning times for Indonesia, due to its vicinity to the Sunda Arc. For this reason the German Indonesian Tsunami Early Warning System (GITEWS) integrates different modern and new scientific monitoring technologies and analysis methods. Behrens, J., Androsov, A., Babeyko, A. Y., Harig, S., Klaschka, F., and Mentrup, L.: A new multi-sensor approach to simulation assisted tsunami early warning, Nat. Hazards Earth Syst. Sci., in review, 2010. Borrero, J. C., Synolakis, C. E., and Fritz, H.: Northern Sumatra Field Survey after the December 2004 Great Sumatra Earthquake and Indian Ocean Tsunami, Earthq. Spectra, 22,S3, S93–S104, 2006. 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