An automated continuous system for seismo-geochemical research in an active fault zone in SW Taiwan

Tuesday, 16 December 2014: 9:45 AM
Tsanyao F Yang1, David R Hilton2, Ching-Chou Fu3, Chun-Wei Lai1, Tsung-Kwei Liu1, Vivek Walia4 and Tzu-Hua Lai5, (1)Natl Taiwan Univ, Dept. Geosciences, Taipei, Taiwan, (2)Univ California San Diego, La Jolla, CA, United States, (3)Institute of Earth Sciences Academia Sinica, Taipei, Taiwan, (4)NCREE National Center for Research on Earthquake Engineering of Taiwan, Taipei, Taiwan, (5)Central Geological Survey, Taipei, Taiwan
Previous studies have revealed that gas compositions of fluid samples collected from southwestern Taiwan where many hot springs and mud volcanoes are distributed along tectonic sutures show significant variation prior to and after some disaster seismic events [1]. Such variations, including radon activity, CH4/CO2, CO2/3He and 3He/4He ratios of gas compositions, are considered to be precursors of earthquakes in this area. To validate the relationship between fluid compositions and local earthquakes, a continuous monitoring station has been established at Yun-Shuei, which is an artesian well located at an active fault zone in SW Taiwan. It is equipped with a radon detector and a quadrupole mass spectrometer (QMS) for in-situ measurement of the dissolved gas composition. Data is telemetered to Taipei so we are able to monitor variations of gas composition in real time. Furthermore, we also installed a syringe pump apparatus for the retrieval and temporal analysis of helium (SPARTAH) at this station [2]. From the SPARTAH samples, we can obtain detailed time series records of He and anion concentration of the water samples at this station. After continuous measurement for a few months, this automated system has been demonstrated to be feasible for long-term continuous seismo-geochemical research in this area. [1] Yang et al. (2006) PAGEOPH, 163(4), 693-709. [2] Barry et al. (2009) G3, 10(5), DOI: 10.1029/2009GC002422.