title: Slow earthquakes coincident with episodic tremors and slow slip events.
abstract: We report on the very-low-frequency earthquakes occurring in the transition zone of the subducting plate interface along the Nankai subduction zone in southwest Japan. Seismic waves generated by very-low-frequency earthquakes with seismic moment magnitudes of 3.1 to 3.5 predominantly show a long period of about 20 seconds. The seismicity of very-low-frequency earthquakes accompanies and migrates with the activity of deep low-frequency tremors and slow slip events. The coincidence of these three phenomena improves the detection and characterization of slow earthquakes, which are thought to increase the stress on updip megathrust earthquake rupture zones.
authors.affiliation: National Research Institute for Earth Science and Disaster Prevention, 3-1 Tennodai, Tsukuba 305-0006, Japan. yito@bosai.go.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Kazushige
authors.initials: K
authors.lastname: Obara
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Shiomi
authors.forename: Shutaro
authors.initials: S
authors.lastname: Sekine
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hirose