International Ocean Discovery Program; Expedition 362 preliminary report; Sumatra seismogenic zone; the role of input materials in shallow seismogenic slip and forearc plateau development; 6 August-6 October 2016

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doi: 10.14379/
Author(s): Dugan, Brandon; McNeill, Lisa C.; Petronotis, Katerina E.; Backman, Jan; Bourlange, Sylvain; Chemale, Farid, Jr.; Chen Wenhuang; Colson, Tobias A.; Frederik, Marina C. G.; Guérin, Gilles; Hamahashi, Mari; Henstock, Timothy; House, Brian M.; Hüpers, Andre; Jeppson, Tamara N.; Kachovich, Sarah; Kenigsberg, Abby R.; Kuranga, Mebae; Kutterolf, Steffen; Milliken, Kitty L.; Mitchison, Freya L.; Mukoyoshi, Hideki; Nair, Nisha; Owari, Satoko; Pickering, Kevin T.; Pouderoux, Hugo F. A.; Shan Yehua; Song, Insun; Torres, Marta E.; Vannucchi, Paola; Vrolijk, Peter J.; Yang Tao; Zhao, Xixi
International Ocean Discovery Program, Expedition 362 Scientists, College Station, TX
Author Affiliation(s): Primary:
Colorado School of Mines, Department of Geophysics, Golden, CO, United States
National Oceanography Centre-Southampton, United Kingdom
Texas A&M University, United States
Stockholm University, Sweden
Ecole Nationalle Supérieure de Géologie, France
Universidade do Vale do Rio dos Sinos, Brazil
Chinese Academy of Sciences, Guangzhou Institute of Geochemistry, China
University of Western Australia, Australia
Agency for the Assessment and Application of Technology, Indonesia
Lamont-Doherty Earth Observatory, Japan
National Institute of Advanced Industrial Science and Technology, Japan
Scripps Institution of Oceanogrpahy, United States
University of Bremen, Germany
University of Wisconsin at Madison, United States
University of Queensland, Australia
Pennsylvania State University, United States
Yamaguchi University, Japan
GEOMAR-Helmholtz Center for Ocean Research Kiel, Germany
University of Texas at Austin, United States
Cardiff University, United Kingdom
Shimane University, Japan
National Centre for Antarctic and Ocean Research, India
Chiba University, Japan
University College London, United Kingdom
University of Rennes I, France
Chinese Academy of Sciences, Key Laboratory of Marginal Sea Geology, China
Korea Institute of Geoscience and Mineral Resources, South Korea
Oregon State University, United States
Royal Holloway-University of London, United Kingdom
New Mexico Institute of Mining and Technology, United States
China Earthquake Administration, China
University of California at Santa Cruz, United States
Source: Preliminary Report - International Ocean Discovery Program, Vol.362, 31p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2372-9562
Note: In English. 66 refs.
Summary: Drilling the input materials of the north Sumatran subduction zone, part of the 5000 km long Sunda subduction zone system and the origin of the Mw ∼9.2 earthquake and tsunami that devastated coastal communities around the Indian Ocean in 2004, was designed to groundtruth the material properties causing unexpectedly shallow seismogenic slip and a distinctive forearc prism structure. The intriguing seismogenic behavior and forearc structure are not well explained by existing models or by relationships observed at margins where seismogenic slip typically occurs farther landward. The input materials of the north Sumatran subduction zone are a distinctively thick (as thick as 4-5 km) succession of primarily Bengal-Nicobar Fan-related sediments. The correspondence between the 2004 rupture location and the overlying prism plateau, as well as evidence for a strengthened input section, suggest the input materials are key to driving the distinctive slip behavior and long-term forearc structure. During Expedition 362, two sites on the Indian oceanic plate ∼250 km southwest of the subduction zone, Sites U1480 and U1481, were drilled, cored, and logged to a maximum depth of 1500 meters below seafloor. The succession of sediment/rocks that will develop into the plate boundary detachment and will drive growth of the forearc were sampled, and their progressive mechanical, frictional, and hydrogeological property evolution will be analyzed through postcruise experimental and modeling studies. Large penetration depths with good core recovery and successful wireline logging in the challenging submarine fan materials will enable evaluation of the role of thick sedimentary subduction zone input sections in driving shallow slip and amplifying earthquake and tsunami magnitudes, at the Sunda subduction zone and globally at other subduction zones where submarine fan-influenced sections are being subducted.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 13 Areal Geology, General; Algae; Areal geology; Asia; Basement; Bengal Fan; Biostratigraphy; Boreholes; Cenozoic; Chemostratigraphy; Cores; Cretaceous; Deformation; Diagenesis; Diatoms; Dinoflagellata; Downhole methods; Earthquakes; East Indian Ocean; Expedition 362; Far East; Foraminifera; Genesis; Geophysical methods; Geophysical profiles; Geophysical surveys; IODP Site U1480; IODP Site U1481; Indian Ocean; Indian Plate; Indonesia; International Ocean Discovery Program; Invertebrata; Lithostratigraphy; Magnetostratigraphy; Marine sediments; Mesozoic; Microfossils; Nannofossils; Nicobar Fan; Paleomagnetism; Palynomorphs; Physical properties; Plantae; Plate tectonics; Pore water; Protista; Quaternary; Radiolaria; Sedimentary rocks; Sediments; Seismic methods; Seismic profiles; Seismic stratigraphy; Subduction; Subduction zones; Sumatra; Sunda Arc; Surveys; Tertiary; Tsunamis; Upper Cretaceous; Well logs
Coordinates: N030202 N030202 E0913621 E0913621
N024517 N024517 E0914535 E0914535
Record ID: 2017050436
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