Site U1437

International Discovery Program (IODP) Site U1437 (proposed Site IBM-3C) is in the Izu-Bonin-Mariana (IBM) arc, which formed in response to subduction of the Pacific plate over the past 52 My. The IBM arc is divided into two major segments, the Mariana arc and the Izu-Bonin arc (Figure F1). The Izu-Bonin arc is further divided into the Izu and Bonin segments (in the north and south, respectively), separated by a fault zone referred to as the Sofugan Tectonic Line (Figure F2, F3); because these segments have somewhat different histories, we refer to them separately as the Izu arc and the Bonin arc. Site U1437 is located in the Izu rear arc, behind the main chain of active volcanoes (referred to as the arc front, Figure F4), about 90 km west of the arc-front Myojinsho Volcano (Figure F5) and 330 km west of the axis of the Izu-Bonin Trench (Figures F1B, F2, F3) at 2117 meters below sea level (mbsl). Site U1437 is about 160 km west-southwest of IODP Site U1436, which was drilled as a 150 m geotechnical hole in preparation for Site IBM-4. Site U1437 is the main objective for IODP Expedition 350.