A Stress Condition in Aquifer Rock for Detecting Anomalous Radon Decline Precursory to an Earthquake
- 183 Downloads
Recurrent groundwater radon anomalous declines were observed from well measurements in the Antung hot spring area (eastern Taiwan) prior to five of six earthquakes that occurred between 2003 and 2011 (M w range 5.0–6.8). The relationship between the detectability of radon anomalies and the first motions of P-waves was investigated. Based on the first motions of P-waves recorded near the investigated well, a precursory decrease in groundwater radon can be detected only when the first motion is compression. No precursory change in groundwater radon concentration was observed for the downward first motion of P-waves.
KeywordsRadon-222 Groundwater Earthquakes P waves Stress
Supports by the Ministry of Science and Technology Taiwan (NSC, MOST), Central Geological Surveys, Industrial Technology Research Institute (L550001060, N550003318), Radiation Monitoring Center, and Institute Earth Sciences of Academia Sinica of Taiwan are appreciated. The authors are grateful to Mr. C. Lin of the Antung hot spring for his kind field assistance.
- Chen, W. S., & Wang, Y. (1996). Geology of the Coastal Range, eastern Taiwan. Geology of Taiwan 7. Central Geological Survey, Taiwan.Google Scholar
- Hashemi, S. M., Negarestani, A., Namvaran, M., & Musavi Nasab, S. M. (2013). An analytical algorithm for designing radon monitoring network to predict the location and magnitude of earthquakes. Journal of Radioanalytical and Nuclear Chemistry, 295, 2249–2262. doi: 10.1007/s10967-012-2310-0.CrossRefGoogle Scholar
- Hsu, T. L. (1962). Recent faulting in the Longitudinal Valley of eastern Taiwan. Geological Society of China, 1, 95–102.Google Scholar
- Nur, A. (1972). Dilatancy, pore fluids, and premonitory variations of ts/tp travel times. Bulletin of the Seismological Society of America, 62, 1217–1222.Google Scholar
- Tuccimei, P., Mollo, S., Soligo, M., Scarlato, P., & Castelluccio, M. (2015). Real-time setup to measure radon emission during rock deformation: implications for geochemical surveillance. Geoscientific Instrumentation, Methods and Data Systems, 4, 111–119. doi: 10.5194/gi-4-111-2015.CrossRefGoogle Scholar