Probable dynamic triggering of phreatic eruption in the Tatun volcano group of Taiwan

Abstract

On 16 March 2014 (UTC), a small phreatic eruption occurred in the Tatun volcano group (TVG) of Taiwan, although it was not reported until analysis of both seismic and acoustic data revealed that the source was in the vicinity of the Hsiaoyukeng fumarole. A replay of the acoustic data accelerated ∼60-fold reveals that the gradual decrease in frequency that was recorded produces a volcanic whistle, similar to the jet of steam released from a heating kettle. The phreatic eruption may have been dynamically triggered by a M6.7 earthquake in Chile. A similar phenomenon occurred on 5 January 2015, when a phreatic eruption was recorded in the TVG immediately after the generation of dynamic seismic waves by an M5.0 earthquake in Japan. This is the first scientific report of a phreatic eruption detected in the TVG, indicating that these volcanoes are still active. As a result, it is important to monitor their volcanic activity and identify volcanic reservoirs beneath the TVG to mitigate future possible volcanic impact.