Release of mineral-bound water prior to subduction tied to shallow seismogenic slip off Sumatra

• DOI: 10.1126/science.aal3429
• Publication Date: 2017-05-25T21:40:11Z
• Authors: Andre Hüpers; Marta E. Torres; Satoko Owari; Lisa C. McNeill; Brandon Dugan; Timothy J. Henstock; Kitty L. Milliken; Katerina E. Petro...; Jan Backman; Sylvain Bourlange; Farid Chemale; Wenhuang Chen; Tobias A. Colson; Marina C. G. Fred...; Gilles Guèrin; Mari Hamahashi; Brian M. House; Tamara N. Jeppson; Sarah Kachovich; Abby R. Kenigsberg; Mebae Kuranaga; Steffen Kutterolf; Freya L. Mitchison; Hideki Mukoyoshi; Nisha Nair; Kevin T. Pickering; Hugo F. A. Pouderoux; Yehua Shan; Insun Song; Paola Vannucchi; Peter J. Vrolijk; Tao Yang; Xixi Zhao
• Keywords: Multidisciplinary; Science & Technology; STRESS; 550; PRISM; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; ZONE; 01 natural sciences; Multidisciplinary Sciences; MODEL; MEGATHRUST; RUPTURE; 13. Climate action; 1000 General; [SDU.STU] Sciences of the Universe [physics]/Earth Sciences; Science & Technology - Other Topics; ANDAMAN EARTHQUAKE; Multidisciplinary, seismogenesis, tsunami, Sumatra; 14. Life underwater; PORE PRESSURE; SEDIMENTS; 0105 earth and related environmental sciences

Plate-boundary fault rupture during the 2004 Sumatra-Andaman subduction earthquake extended closer to trench than expected, increasing and tsunami size. International Ocean Discovery Program Expedition 362 sampled incoming sediments offshore northern Sumatra, revealing recent release of fresh water within deep sediments. Thermal modeling links this freshening amorphous silica dehydration driven by rapid burial-induced temperature increases in past 9 million years. Complete silicates is expected before plate subduction, contrasting with prevailing models for seismogenesis calling fluid production subduction. Shallow slip Sumatra appears diagenetic strengthening deeply buried fault-forming sediments, weakening proposed shallow Tohoku-Oki 2011 rupture, but our results are applicable other thickly sedimented zones including those limited records.