10-10-2012, 05:25 PM
EFFORTS OF EARTHQUAKE DISASTER MITIGATION USING EARTHQUAKE EARLY WARNING IN JAPAN
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ABSTRACT
In Japan MEXT, NIED, JMA and NGOs (JWA and REIC) cooperated to develop an earthquake early warning
(EEW) system of the general use, for mitigating earthquake disasters during 2003-2007. Data are from the
network of JMA and the network (Hi-net) of NIED. Those data are collected in real-time with small
transmission delay and analyzed by the system developed by NIED and JMA. Present information officially
issued from JMA has seismic focal parameters and estimated strength of seismic motions at chosen place of
sites. REIC and JWA have taken charge of R/D of application system and social response, respectively.
Once earthquakes occur, the focal parameters are calculated as quickly as enough number of observation sites
sense seismic waves. EEW are transmitted generally in several seconds after detecting seismic signal at the
nearest sites. The disseminated parameters can be used by any people and organizations. REIC and its members
developed special application systems to help various countermeasures including automated and/or
semi-automated responses. These systems estimate specific information for particular users at particular site for
triggering the systems. Now we have developed 14 kinds of application systems. From October 1, 2007 EEW
has been in the practical utilization: the general use by broadcasting companies (TV, radio, and mobile phone)
and contracted use by private companies and REIC using special application instruments. The systems have
been gradually adopted for earthquake disaster mitigation.
KEYWORDS:
Earthquake, Disaster Mitigation, Early Warning, Real-time, Counter-measure Equipment,
INTRODUCTION
Previous real-time earthquake information for public use in the 1990s has focused on time ranging from several
tens of minutes up to 24 hours after earthquake hits. It aims to provide information for emergency management
products which help local governments and enterprises to carry out disaster prevention activities. Those
available systems work primarily for the loss estimation using data obtained by dense strong-motion
seismometer network of local government after large earthquakes occur.
This paper presents efforts to develop EEW (e.g., Cooper, 1868, Hakuno and Takahashi, 1972; Nakamura,
1988; Kanamori, 2005) in Japan. The National Research Institute for Earth Science and Disaster Prevention
(NIED) and the Japan Meteorological Agency (JMA) established nationwide extensive seismic networks after
the 1995 Kobe earthquake. In these networks the high-sensitivity seismograph network (Hi-net) of NIED and
the Tsunami and Earthquake Observation and Monitoring of JMA transmit data in real-time. The two
organizations independently developed EEW systems. The former uses network data for a practical application
of the resource (Fujinawa et al, 2003; Horiuchi et al, 2005). And the latter uses data for development of the
“Nowcast” Information (Tsukada et al, 2004; Kamigaichi, 2004). Although there may typically be a mere 1 to
10 seconds before the earthquake ground motion, this brief lead time can be useful not only for safety of lives,
but also for protection of property and information in numerous fields of application.
After the efforts by two organizations, a new R/D was started aiming at practical applications during 2003-2007.
The project was conducted through the collaboration of industries, academic community, governmental
organizations of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), NIED and JMA,
and NGOs (REIC, Japan Weather Association (JWA)) (MEXT and NIED, 2003; 2004; 2005: 2006). In Japan we
assumed the users to be the whole people and organization. Here, we will present outline of this project, and
describe how the EEW technology was developed into effective utilization. Especially we focus on the research
and development of the application system for various fields to assist each disaster mitigation efforts.
METHOD
In the general use, it is necessary to take a different approach in R/D: a scheme of cooperation among central
and local governments, and NGOs as shown in Figure 1. The data is essentially from the seismic network by
government or national institute. But user’s seismometers could be subsidiary used in the near future. Data
collection and analyses for EEW are conducted by the governmental organization as JMA in Japan. Another
important difference is in the substantial participation of private companies and individuals in the “business”.
Application systems should be developed, sold and maintained in the market. EEW information is delivered to
any of contracted users. Instruments, service and data should also be developed in the market. There are many
units in the society involved in EEW business. REIC was established as a liaison organization to promote the
project in 2003.
RESULTS
Main results are briefly shown as follows. The detail can be seen in MEXT and NIED (2003, 2004, 2005, 2006).
3.1 Introduction of Application Systems
It was recommended by the prime ministry to use EEW as a practical means of earthquake disaster mitigation in
central government, local government offices and many public fields. The application system has started to
prevail gradually in the whole country now, especially after the major earthquakes during the first half year.