1. Introduction

Early warning systems are used to alert users a few seconds before a strong earthquake hits the protected area. The system is able to detect the primary p-waves of an earthquake and produce am alarm prior s-waves arrival. The system can be used to switch off critical facilities or machines and alert people for upcoming earthquakes.

2. Principles of Operation

Typically, acceleration sensors are installed in the surrounding area of the protected infrastructure. Several sensors are required for making sure that the system will be not noise sensitive. The sensor is transmitting data in real time to a server which runs special acquisition & analysis software. The software using quick earthquake detection mechanisms, mainly based on the quick detect of the p-wave arrival of an earthquake, is able to generate an alarm and activate a switch relay in case of an earthquake.

3. Installation

Low-cost hardware is used for this application, like the GEOBIT GEOwarning low cost accelerograph. The accelerographs operate in trigger mode so they are able to generate a trigger in case of earthquake. The trigger information is transmitted to the GEOedge software, that decided if the triggers are related with an earthquake or not. If yes, the GEOegde informs the user via email-sms an instantly generates a switch relay (or more if required) which is connected to the acquisition computer.