Advances in earthquake and tsunami sciences and disaster risk reduction since the 2004 Indian ocean tsunami

Abstract

The December 2004 Indian Ocean tsunami was the worst tsunami disaster in the world's history with more than 200,000 casualties. This disaster was attributed to giant size (magnitude M~9, source length >1000 km) of the earthquake, lacks of expectation of such an earthquake, tsunami warning system, knowledge and preparedness for tsunamis in the Indian Ocean countries. In the last ten years, seismology and tsunami sciences as well as tsunami disaster risk reduction have significantly developed. Progress in seismology includes implementation of earthquake early warning, real-time estimation of earthquake source parameters and tsunami potential, paleoseismological studies on past earthquakes and tsunamis, studies of probable maximum size, recurrence variability, and long-term forecast of large earthquakes in subduction zones. Progress in tsunami science includes accurate modeling of tsunami source such as contribution of horizontal components or "tsunami earthquakes", development of new types of offshore and deep ocean tsunami observation systems such as GPS buoys or bottom pressure gauges, deployments of DART gauges in the Pacific and other oceans, improvements in tsunami propagation modeling, and real-time inversion or data assimilation for the tsunami warning. These developments have been utilized for tsunami disaster reduction in the forms of tsunami early warning systems, tsunami hazard maps, and probabilistic tsunami hazard assessments. Some of the above scientific developments helped to reveal the source characteristics of the 2011 Tohoku earthquake, which caused devastating tsunami damage in Japan and Fukushima Dai-ichi Nuclear Power Station accident. Toward tsunami disaster risk reduction, interdisciplinary and trans-disciplinary approaches are needed for scientists with other stakeholders.

Bodrum–Kos (Turkey–Greece) Mw 6.6 earthquake and tsunami of 20 July 2017: a test for the Mediterranean tsunami warning system

“…The near-field tsunami threats are a challenge for tsunami warning systems around the world because of the short tsunami travel times (e.g., 15-20 min) and incapability of the current technologies to accurately estimate earthquake magnitudes in such a short time (e.g., Ozaki 2011). It is believed that the earthquake ground shaking is the first warning message for the coastal communities in the area emphasizing the importance of tsunami awareness and education for coastal communities (e.g., Synolakis and Okal 2005;Satake 2014). The components of tsunami warning systems in the near-field conditions of the Mediterranean Basin have been discussed by a number of authors among which are Ozel et al (2011), Papadopoulos andFokaefs (2013), andNecmioglu (2016).…”

“…Although powerful tsunamis from M > 8 earthquakes occur almost annually in the Pacific Ocean (e.g., Synolakis et al 2002;Fritz et al 2012;Suppasri et al 2013;Satake 2014;Heidarzadeh et al 2016a;Shimozono and Sato 2016;Saito 2017;Ishibe et al 2017), such events are less frequent in the Mediterranean Sea. Therefore, analysis of this moderate tsunami contributes toward tsunami assessment and awareness in this enclosed basin and tests the functional performance of TSPs in the NEAMTWS region.…”

Unusual geologic evidence of coeval seismic shaking and tsunamis shows variability in earthquake size and recurrence in the area of the giant 1960 Chile earthquake

“…Tohoku earthquakes and tsunamis underscore the importance of using geological evidence 59 to help estimate the variability among earthquakes that a given subduction zone can 60 produce (Satake, 2014). Variable rupture mode, in which a long segment of a subduction 61 zone sometimes ruptures in a single great earthquake, but in other times ruptures in a series 62 of relatively smaller earthquakes (Kanamori and McNally, 1982), was inferred decades ago 63 from written records of earthquakes between AD 684 and 1946 in southwest Japan (Ando,64 …”

Accurate local magnitude prediction for small to moderate earthquakes using rapid calculations of P-wave dominant period

“…Such invaluable information is vital for preventing local community living in possibly impacted areas from potential damages of structures and possible losses of lives (Shieh et al, 2008;Satriano et al, 2011). Within the context of disaster risk reduction program, the rapid release of public information on the earthquake magnitude has to be accurate because accuracy is one of the two crucial elements required for the development of reliable disaster early warning (Satake, 2014).…”