Skip to main content
Progress in Earth and Planetary Science
Fig. 8 | Progress in Earth and Planetary Science

Fig. 8

From: Fault geometry of M6-class normal-faulting earthquakes in the outer trench slope of Japan Trench from ocean bottom seismograph observations

Fig. 8

Mainshock and aftershock activity of the November 12, 2017 earthquake. a Map showing the epicenter distribution of the November 12, 2017 earthquake and its aftershocks. The mainshock and its aftershocks that occurred through November 14 within the dashed rectangles are indicated by circles color-coded with time after the mainshock as indicated in panel (b). The mainshock is marked with a green star. The focal mechanism of the mainshock from the GCMT catalog is indicated. b Magnitude-time diagram of the earthquakes within the dashed rectangles on panel (a). c Cross section of the hypocenters along profile A–A’ on panel (a). The gray rectangle indicates the area of the earthquakes that occurred within 1 h from the mainshock. d Cross section of the hypocenters along profile B–B’ on panel (a). The thick arrow indicates the aftershock distribution corresponding to the northwestward-dipping plane of the GCMT solution. Thin arrows indicate the M \(\sim\)4 aftershocks located below the northwestward-dipping plane. e, f Cross sections of the hypocenters along the profile C–C’ on panel (a). Focal mechanisms from the OBS first-motion polarities are also indicated on panel (f). The focal mechanisms are color-coded by the faulting types according to the triangle diagram of Frohlich (1992), as shown in Fig. 2. Thick arrows indicate the aftershock distribution corresponding to the westward-dipping plane of the focal mechanisms from the OBS first-motion polarities

Back to article page