Variations of soil radon and thoron concentrations in a fault zone and prospective earthquakes in SW Taiwan

• Published in: Radiation measurements Vol. 40; no. 2; pp. 496 - 502
• Main Authors: Yang, T.F., Walia, V., Chyi, L.L., Fu, C.C., Chen, C.-H., Liu, T.K., Song, S.R., Lee, C.Y., Lee, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2005; Elsevier
• Subjects: 3He/ 4He ratio; Earth sciences; Earth, ocean, space; Earthquake monitoring; Earthquakes, seismology; Engineering and environment geology. Geothermics; Exact sciences and technology; Geochronology; Internal geophysics; Isotope geochemistry. Geochronology; Natural hazards: prediction, damages, etc; Radon; Soil gas; Taiwan; Thoron; Far East; Taiwan; 3He/ 4He ratio; Thoron; Earthquake monitoring; Soil gas; Radon; Taiwan; radon; concentration; helium; He-4/He-3; monitoring; earthquakes; Rn-220; Rn-222; Asia; active faults; isotopes; radioactive decay; fault zones; magnitude; 3He/4He ratio; soil gases
• ISSN: 1350-4487; 1879-0925
• DOI: 10.1016/j.radmeas.2005.05.017

An automatic station for soil gas monitoring was set up on an active fault zone of SW Taiwan. After more than one year of continuous measurements, some spike-like anomalous high radon and thoron concentrations could be observed. A similar soil radon spectrum was also obtained from an independent monitoring station, which was only 100 m away. These anomalous peaks usually occurred a few days or weeks before the earthquakes ( M L ⩾ 4.5 ) . This indicates that variations of both soil radon and thoron can serve as useful tools for earthquake surveillance, esp. at fault zones.