The quickest response--Analysis of Japan Earthquake Early Warning System

Earthquake alarm systems are also called real-time earthquake disaster prevention systems. After an earthquake occurs, earthquake source elements and seismic distribution information are obtained, and this information is transmitted to various users (disaster officials, electricity, gas, water, telephone, traffic, media, and individuals) to prepare them for disaster prevention. . When an earthquake occurs, an alarm is issued to try to minimize the damage to the safety management system. The earthquake warning system in Japan is broadly divided into two categories. The two operating modes are listed below.

Early Warning System (Early Earthquake Early Warning System, Instant Message): Send an alarm before the earthquake to prevent the loss of the Urdesnas of the Shinkansen: pre-detection and control equipment. Currently, with the evolution of UrEDAS, it has been applied to rail transportation such as the Shinkansen.

SAS, Sistema de Alerta Sísmica: A warning order was issued at the start of the earthquake.

The Meteorological Agency’s emergency earthquake quick report is undertaken by private companies for distribution services, such as ANET, a group company of the Railroad Institute of Integrated Technology.

Early Earthquake Alarm System: The use of the Emergency Earthquake Express has been adopted by all railway operators except the Kyushu Shinkansen.

FREQL (Fast Response Equipment for Quake Load quick response to equipment load): It has UrEDAS and CompactUrEDAS functions. For P-wave detection within 1 second, the shortest to send an alarm signal in 0.2 seconds, is the world's fastest.

Post-earthquake information (post-earthquake, post-earthquake information): Forecasts of losses, etc. Launch appropriate disaster prevention measures Tokyo oil and gas signals, Supreme Court: Loss control, equipment control.

Yokohama High Density Strong Earthquake Measurement Network: Understand the disaster situation after the earthquake.

Kawasaki City Earthquake Disaster Countermeasure Support System: Understand the disaster situation after the earthquake.

Cabinet Government Early Earthquake Loss Assessment System (EES): Understand the disaster after an earthquake.

Southern California CUBE: post-earthquake information release.

Seismic wave seismic alarm system is a system that was developed based on the observation of micro-motion in the early stage of earthquakes and timely response measures to minimize the loss in the early stage.

When the earthquake occurred, there were mainly two seismic waves spreading to the surrounding area. The S wave in the seismic wave is greatly shaken. It is a seismic wave that causes loss and spreads relatively slowly. P-wave is not a seismic wave that causes loss because it generates micro-motion at the beginning of the earthquake. P-waves spread at twice the speed of S-waves, so observation of P-waves and rapid transmission of information can effectively prevent losses.

This principle is very simple. Similar ideas existed in early 1900. However, due to lack of knowledge, technology, and funding, such as communication, observation, and processing (judging the existence of earthquakes), experiments and use began only after 1990.

At the Institute of Railway Integrated Technology, early earthquake alarms developed using new methods have been used on the Shinkansen. The new system is to predict the source of the earthquake and the magnitude of the earthquake from the initial shaking of the P wave, and issue an alarm before the big shock starts. This is the same as the previous UrEDAS, but the method of estimation is different. The new system is to first determine the distance from the beginning of the seismic P wave to the steep peak as a significant feature to the source. And based on the estimation of the maximum size of the part from the P wave amplitude. This new method improves the accuracy of the source distance and magnitude estimation.