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1401.5 mbsf (Hole C0002A; Expedition 314 Scientists, 2009a) and 0 to 980 mbsf (Hole C0002G; Expedition 332 Scientists, 2011). Coring at Site C0002 previously sampled 0-203.5 mbsf (Holes C0002C and C0002D) and 475-1057 mbsf (Hole C0002B) (Expedition 315 Scientists, 2009b). During riser operations, we expanded the data sets at Site C0002. Gas from drilling mud was analyzed in near real time in a mud-gas monitoring laboratory and was sampled for postcruise research. Continuous LWD/MWD data were collected in real time for quality control and for initial assessment of borehole environment and formation properties. Recorded-mode LWD data provided higher spatial sampling of downhole parameters and conditions. Cuttings were sampled for standard shipboard analyses and shore-based research. Riserless Methods 1

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The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is a multidisciplinary scientific project designed to investigate fault mechanics and seismogenesis along subduction megathrusts through reflection and refraction seismic imaging, direct sampling, in situ measurements, and long-term monitoring in conjunction with laboratory and numerical modeling studies. The fundamental scientific objectives of NanTroSEIZE include characterizing the nature of fault slip and strain accumulation, fault and wall rock composition, fault architecture, and state variables throughout an active plate boundary system. As part of the NanTroSEIZE program, operations during Integrated Ocean Drilling Program (IODP) Expedition 338 were planned to extend and case riser Hole C0002F, begun during IODP Expedition 326 in 2010, from 856 to 3600 meters below seafloor (mbsf). Riser operations extended the hole to 2005.5 mbsf, collecting a full suite of logging-while-drilling (LWD) and measurement-while-drilling, mud gas, and cuttings data. However, because of damage to the riser during unfavorable wind and strong current conditions, riser operations were cancelled. Hole C0002F was suspended at 2005.5 mbsf and left for reentry during future riser drilling operations, which will deepen the hole to penetrate the megasplay fault at 5000 mbsf.Contingency riserless operations included coring at Site C0002 (200-505, 902-940, and 1100.5-1120 mbsf), LWD at IODP Sites C0012 (0-710 mbsf) and C0018 (0-350 mbsf), and LWD and coring at IODP Sites C0021 (0-294 mbsf) and C0022 (0-420 mbsf). These sites and drilling intervals represent key targets not sampled during previous NanTroSEIZE expeditions but relevant to comprehensively characterize the alteration stage of the oceanic basement input to the subduction zone, the early stage of Kumano Basin evolution, gas hydrates in the forearc basin, recent activity of the shallow megasplay fault zone system, and submarine landslides.