Detector

Radon gas

Nuclear physics

Passive seismic

Seismology

Geology

Physics

Optics

Sampling (signal processing)

Environmental science

Radon

Earth Systems and Environment

This paper reports a review on the relationship between seismic activity and the emissions of CO 2 and radon. Direct, indirect and sampling methods are mainly employed to measure CO 2 flux and concentration in seismic areas. The accumulation chamber technique is the mostly used in the literature. Radon gas emission in seismic areas can be considered as a short-term pre-seismic precursor. The study and the measurement of radon gas activity prior to earthquakes can be performed through active techniques, with the use of high-precision active monitors and through passive techniques with the use of passive detectors. Several investigators report models to explain the anomalous behavior of in-earth fluid gasses prior to earthquakes. Models are described and discussed.

CO2 and Radon Emissions as Precursors of Seismic Activity