Correlation between Variations in Chemical Compositions of Volcanic Gas and the Earthquake in Shihlin, Taipei City in 2014

Correlation between Variations in Chemical Compositions of Volcanic Gas and the Earthquake in Shihlin, Taipei City in 2014

The Tatun Volcano Group (TVG) is an active volcano located only approximately 15 km north of metropolitan Taipei. Two nuclear power plants are also located a few kilometers northeast of the TVG. Thus, carefully monitoring the volcanic activity is essential for residents in northern Taiwan. In the past decade, fumarolic gas samples have been regularly collected in order to record the variations in chemical compositions and helium isotope ratios. The results indicate that the volcanic activity of the TVG is stable. On February 12, 2014, an earthquake of Richter magnitude 4.2 occurred in the study area. After the earthquake, HCl concentration increased dramatically in the gas of a few fumaroles. This unique feature is useful for establishing a detailed model to depict the hydrothermal systems of the TVG. We believe that our data will fill a gap in current knowledge of the TVG and can provide crucial information for investigating the tectonic settings of northern Taiwan.