Conceptual model of the Merapi summit. A. A NNW–SSE directed fracture zone responsible for the alignment of Merapi and adjacent volcanoes (the Merapi–Merbabu trend) is
causing fractures at the Merapi summit dome. B. During the Nov 18, 2013 explosion, the dome splitted in two halves, the fracture trend is NW–SE. C. Left lateral motion along the
Merapi–Merbabu trend may explain the structures seen on Merapi and the counterclockwise rotation of the 18 No 2013 lava dome fracture. C. Modified fromMathieu et al. (2011).
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