[S21-P] Poster

[S21-P-16] Tectonic Tremor in northern Central Range, Taiwan

^○Wei-Fang Sun¹, Cheng-Horng Lin^{2, 3}, Yi-Heng Li⁴, Wen-Yen Chang^1,3 (1.National Dong Hwa University, Hualien, Taiwan, 2.Academia Sinica, Taipei, Taiwan, 3.National Center for Research on Earthquake Engineering, Taipei, Taiwan, 4.Industrial Technology Research Institute, Hsinchu, Taiwan)

Triggered and ambient tectonic tremor has been observed in the Island of Taiwan, an active and oblique collision between the Eurasian and the Philippine Sea plates.  A few triggered tremor sources have been found in norther Central Range but no further details have been reported. Different from regular earthquakes, deep tremor is difficult to detect and locate across a sparse seismic network due to its non-impulsive, low-amplitude property. In this study, we combine four seismic networks operated by different institutes, containing seismic data from tens of broadband and short period stations for average station spacing less than 10 km. We manually detect tectonic tremor through continuous data from 2013 to 2015. For triggered tremor, we examine waveform within 1,200 s after distant earthquakes, epicentral distance more than 1,000 km and magnitude more than 7.5, and 120 s after local earthquakes, epicentral distance less than 100 km and magnitude more than 5.0. We assume tremor only has clear S-wave, use waveform envelope to identify S-wave arrivals, and locate triggered tremor by hypo71. For ambient tremor, we manually check continuous data for extracting tremor events lasting longer than 3 minutes, and apply the same procedure to locate them. Combining the spatiotemporal distributions of the two types of tectonic tremor and local earthquakes, we further discuss the possible mechanism for interactions between earthquakes and tectonic tremor.