Differences in Subjective Estimation of Risks and Assessment for the Modified Tsunami Warning System by the Japan Meteorological Agency Among University Students Located in Damaged and Non-Damaged Prefectures Around the Period of the 2011 off Pacific Coast of Tohoku Earthquake

2014 ◽  
Vol 9 (4) ◽  
pp. 571-578 ◽  
Author(s):  
Erina Gyoba ◽  

The Japan Meteorological Agency (JMA) released a new version of tsunami warning system using three qualitative expressions for tsunami height. Understanding disaster mitigation information requires adequate knowledge on disaster occurrence mechanisms and precise action in emergencies. We surveyed differences in understanding and assessing tsunami warning information among university students in two prefectures – one damaged by the 2011 off Pacific Coast of Tohoku Earthquake and the other outside of the damage zone. Results revealed that those outside of the damage zone tended to estimate tsunami heights as higher than those inside the damage zone when reading qualitative tsunami heights in the JMA’s new tsunami warning version. They also tended to need more concrete, precise information to understand appropriate evacuation procedures provided by public institutions, including the JMA.

2009 ◽  
Vol 4 (4) ◽  
pp. 595-599 ◽  
Author(s):  
Fumihiko Imamura ◽  
◽  
Ikuo Abe

History of development of Tsunami Warning System in Japan started in 1952 after the tsunami warning/forecast system formulated at Sanriku is introduced. The system estimated the earthquake epicenter and magnitude, and issued the forecast by referring to the tsunami forecast maps. In 1999, the Japan Meteorological Agency (JMA) has introduced the computer-aided simulation system for quantitative tsunami forecasting, in which tsunami arrival times and heights are simulated and stored in the database for forecasting tsunamis. The JMA has been further updating the system and now can issue the forecast 2 to 3 minutes after occurrence of an earthquake. By reviewing the response of the people for past tsunamis forecasting and information in an example case of the 2006 Kurile Earthquake tsunami, we discuss the issues such as accuracy, detail and canceling in order to improve the system.


2012 ◽  
Vol 7 (sp) ◽  
pp. 439-445 ◽  
Author(s):  
Tomoaki Ozaki ◽  

The Japan Meteorological Agency (JMA) issued a timely tsunami warning three minutes after the 2011 off the Pacific coast of Tohoku Earthquake (the Great Tohoku Earthquake) occurred at 14:49 (JST) on March 11, 2011. However, predicted tsunami heights at the early stage were greatly underestimated. Based on lessons learned from this earthquake, the JMA plans to improve its tsunami warning.


1987 ◽  
Vol 11 (2-3) ◽  
pp. 213-220 ◽  
Author(s):  
W. J. Rapatz ◽  
T. S. Murty

2015 ◽  
Vol 10 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Yohko Igarashi ◽  
◽  
Toshihiro Ueno ◽  
Kenji Nakata ◽  
Vilma C. Hernandez-Grennan ◽  
...  

To enhance the tsunami warning operation system in the Philippines caused by earthquakes in and around the country, staff members of the Japan Meteorological Agency (JMA) joined the SATREPS program in 2012 to help building a tsunami simulation database in the Philippine Institute of Volcanology and Seismology (PHIVOLCS), which storesmultiple results of tsunami simulations such as estimated tsunami arrival times and heights at coasts for multiple hypothetical earthquakes of various hypocenter locations and magnitudes. The procedure to construct a database consists of several steps starting from setting assumed fault parameters and others, proceeding to tsunami simulations and data creation to be stored in the database, and as the last step, creating a searching system which picks results from the database according to the location and magnitude of an earthquake. As of July 2014, the PHIVOLCS has stored the results of tsunami simulations conducted for more than 30,000 assumed faults for local tsunamis. The searching system is also prepared which enables to get a quick grasp of expected tsunami features quantitatively. With this database and the searching system, the PHIVOLCS is in near future to issue initial tsunami warnings based on the information of estimated tsunami arrival times and heights immediately after the hypocenter location and magnitude of an earthquake are determined. When the necessary coordination with related organizations as well as the public education for the system and warning messages are ready, the PHIVOLCS will start the enhanced local tsunami warning operation.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Yuchen Wang ◽  
Kenji Satake ◽  
Iyan E. Mulia

AbstractWestern Mediterranean Basin (WMB) is among tsunamigenic zones with numerous historical records of tsunami damage and deaths. Most recently, a moderate tsunami on 21 May 2003 offshore Algeria, North Africa, was a fresh call for strengthening tsunami warning capabilities in this enclosed water basin. Here, we propose to deploy offshore bottom pressure gauges (OBPGs) and to adopt the framework of a tsunami data assimilation (TDA) approach for providing timely tsunami forecasts. We demonstrate the potential enhancement of the tsunami warning system through the case study of the 2003 Algeria tsunami. Four scenarios of OBPG arrangements involving 10, 5, 3 and 2 gauges are considered. The offshore gauges are located at distances of 120–300 km from the North African coast. The warning lead times are 20, 30, 48 and 55 min for four points of interest considered in this study: Ibiza, Palma, Sant Antoni and Barcelona, respectively. The forecast accuracies are in the range of 69–85% for the four OBPG scenarios revealing acceptable accuracies for tsunami warnings. We conclude that installation of OBPGs in the WMB can be helpful for providing successful and timely tsunami forecasts. We note that the OBPG scenarios proposed in this study are applicable only for the case of the 2003 Algeria tsunami. Further studies including sensitivity analyses (e.g., number of OBPG stations; earthquake magnitude, strike, epicenter) are required in order to determine OBPG arrangements that could be useful for various earthquake scenarios in the WMB.


Author(s):  
J. Selva ◽  
A. Amato ◽  
A. Armigliato ◽  
R. Basili ◽  
F. Bernardi ◽  
...  

AbstractDestructive tsunamis are most often generated by large earthquakes occurring at subduction interfaces, but also other “atypical” sources—defined as crustal earthquakes and non-seismic sources altogether—may cause significant tsunami threats. Tsunamis may indeed be generated by different sources, such as earthquakes, submarine or coastal landslides, volcano-related phenomena, and atmospheric perturbations. The consideration of atypical sources is important worldwide, but it is especially prominent in complex tectonic settings such as the Mediterranean, the Caribbean, or the Indonesian archipelago. The recent disasters in Indonesia in 2018, caused by the Palu-Sulawesi magnitude Mw 7.5 crustal earthquake and by the collapse of the Anak-Krakatau volcano, recall the importance of such sources. Dealing with atypical sources represents a scientific, technical, and computational challenge, which depends on the capability of quantifying and managing uncertainty efficiently and of reducing it with accurate physical modelling. Here, we first introduce the general framework in which tsunami threats are treated, and then we review the current status and the expected future development of tsunami hazard quantifications and of the tsunami warning systems in Italy, with a specific focus on the treatment of atypical sources. In Italy, where the memory of historical atypical events like the 1908 Messina earthquake or the relatively recent 2002 Stromboli tsunami is still vivid, specific attention has been indeed dedicated to the progressive development of innovative strategies to deal with such atypical sources. More specifically, we review the (national) hazard analyses and their application for coastal planning, as well as the two operating tsunami warning systems: the national warning system for seismically generated tsunamis (SiAM), whose upstream component—the CAT-INGV—is also a Tsunami Service Provider of the North-eastern Atlantic, the Mediterranean and connected seas Tsunami Warning System (NEAMTWS) coordinated by the Intergovernmental Coordination Group established by the Intergovernmental Oceanographic Commission (IOC) of UNESCO, and the local warning system for tsunamis generated by volcanic slides along the Sciara del Fuoco of Stromboli volcano. Finally, we review the state of knowledge about other potential tsunami sources that may generate significant tsunamis for the Italian coasts, but that are not presently considered in existing tsunami warning systems. This may be considered the first step towards their inclusion in the national tsunami hazard and warning programs.


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