 The NEC ridge is lying on Damar Basin, a sea basin of which has 1–2 km Pliocene–Quaternary sediment thickness and is topologically flat.Damar Basin is located in Banda Sea, which is bounded by East Sunda and Banda volcanic arcs within the area of three major plates, namely Eurasian, Pacific and Indo-Australian plates; all of the three plates have been actively converging since Mesozoic times.The two submarine volcanoes (the Emperor of China and Nieuwerkerk) are located at both ends of the NEC ridge, and they were active.