Fig. 1

Map of northern Taiwan showing the locations of two extremely shallow earthquakes (blue circles), seismic stations of the Formosa Array (black triangles), the Tatun Volcano Group (red dashed-circle zone), the Shanchiao Fault (green dashed line), the magma reservoir (elliptical red area), and Taipei City (yellow square). The study area is marked by a square in the inset map of Southeast Asia.