Seismic Sensor Network for High Density Deployments: Concept, Design, Deployment and Results

Abstract

The devastating impact that seismic events can cause to societies demands that the underlying physical processes that cause them are better under- stood. Seismic networks have been increasingly deployed over the years allow- ing to measure ground motion with great accuracy and, in a few cases, reaching high-density deployments for high-resolution measurements. In this chapter it is described the work conducted to build a high-density seismic network comprised of low-cost network-enabled accelerometer sensors to monitor the Alentejo region. The design resulted in a modular platform that can operate with different sensors. Following a noise performance evaluation, the Analog ADXL355 accelerome- ter was selected for the deployment phase. Herein, sensor system measurements were compared with a professional seismometer, using two actual seismic events recorded in Portugal. These events allowed to demonstrate the sensors capabilities in detecting weak (2.5 ML) to moderate (3.4 ML) seismic events at short (8 km) and medium (140 km) distances respectively. Comparing obtained measurements with a professional seismometer, however, the sensor prototypes exhibited, as expected, a higher presence of sensor noise. Overall it is concluded that the sensor system has a potential application in seismology.