Tectonic Early Warning System Through Real-Time Radon (Rn) Monitoring: Preliminary Results of a Geophysical Method for Forecasting Earthquakes

Abstract

Earthquakes are a major natural hazard in numerous parts of the world, and research into precursor signals of seismic activity has mobilised the scientific community for many years. Since earthquakes are a physical phenomenon, attempts for predicting these events in terms of date, magnitude and epicenter have traditionally called upon geophysical methods (seismology, deformation of the ground, electrical methods, etc.). In order to understand more the underlying processes involved, it is necessary to undertake extended periods of monitoring of individual gases at one or more locations, and statistically analyze the compositional data in relation to the observed seismic activity and the effects of extraneous variables. These geophysical anomalies indicate that the faults are zones of weakness acting as channels for deep degassing processes. Numerous successes in forecasting were subsequently recorded through the study of radon emanation in the soils and ground waters of seismic zones. Research into earthquake precursor signals requires continuous instrument surveillance of the selected geophysical parameters.

The final objective of this research work is to be able to estimate and prognoses a seismic event. Throughout a one-year period of our research work, we have collected sufficient soil-gas data over long periods at one or more recognized seismically active localities in Greece, Russia, Armenia, and Albania as a preliminary work to establishing a capability for earthquake prediction based on variations in soil gas composition. With the already studied results we are able to demonstrate the viability of the technique, followed by establishment of permanent monitoring stations. The information obtained from these surveys will be compared to data from on-going parallel studies in Greece where all data will be collected via satellite in real-time. Emphasis will be placed on the development of methodology and software suitable for the extended monitoring of gas composition on-site, supported by laboratory determinations to validate the field data where necessary. A number of data loggers (i.e. transducers/detectors) have already been installed at specific selected locations (base stations). Each base station includes a data-logger with which a number of geological parameters are detected. The data are transmitted to a modem, which is directly attached to the INMARSAT global satellite communication system. With the above mentioned multi-disciplinary approach we intend to establish a permanent central data acquisition-broadcasting system with a continuous monitoring of radon, water table level, groundwater temperature, atmospheric temperature and pressure, carbon dioxide, helium, nitrogen, etc.