The SZ4D Initiative Understanding the Processes that Underlie Subduction Zone Hazards in 4D A Vision Document Submitted to the National Science Foundation The SZ4D Initiative Understanding the Processes that Underlie Subduction Zone Hazards in 4D A Vision Document Submitted to the National Science Foundation Writing Committee Co-chair: Jeff McGuire Woods Hole Oceanographic Institution Co-chair: Terry Plank Lamont-Doherty Earth Observatory of Columbia University Sergio Barrientos Centro Sismologico, Universidad de Chile Thorsten Becker Institute for Geophysics, University of Texas at Austin Emily Brodsky University of California, Santa Cruz Elizabeth Cottrell National Museum of Natural History, Smithsonian Institution Melodie French Rice University Patrick Fulton Texas A&M University Joan Gomberg United States Geological Survey Sean Gulick Institute for Geophysics, University of Texas at Austin Matt Haney United States Geological Survey, Alaska Volcano Observatory Diego Melgar University of California, Berkeley Sarah Penniston-Dorland University of Maryland Diana Roman Carnegie Institution of Washington Phil Skemer Washington University in St. Louis Harold Tobin University of Wisconsin-Madison Ikuko Wada University of Minnesota Doug Wiens Washington University in St. Louis With Input from Kate Allstadt United States Geological Survey, Denver Fidel Costa Earth Observatory of Singapore Emma Hill Earth Observatory of Singapore Ray Wells United States Geological Survey Jane Willenbring Scripps Institution of Oceanography Acknowledgments The Subduction Zone Observatories workshop was made possible by funding from the National Science Foundation, including the EAR and OCE divisions as well as the International Programs Office. The USGS and NASA provided support for their scientists to attend. Funding to support international participants was also provided by the Earth Observatory of Singapore. The workshop was organized through a grant to the Incorporated Research Institutions for Seismology (IRIS, co-PIs A. Meltzer and R. Detrick). The organizing committee wishes to thank Andy Frassetto, Krystin Poitra, and the rest of the IRIS staff who contributed to organizing both the workshop itself, the meeting website, and the report. The report authors thank Donna Blackman, Donna Shillington, Greg Beroza, Mark Brandon, Peter van Keken, Kaj Hoernle, Louise Kellogg, and Shuichi Kodaira for thorough and helpful reviews of this document. The report was published with the help of Geo Prose Inc. Preferred Citation McGuire, J.J., T. Plank, et al. 2017. The SZ4D Initiative: Understanding the Processes that Underlie Subduction Zone Hazards in 4D. Vision Document Submitted to the National Science Foundation. The IRIS Consortium, 63 pp. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Table of Contents EXECUTIVE SUMMARY ..........................................................................................................................................................................................................................................................1 1. INTRODUCTION ..........................................................................................................................................................................................................................................................................2 2. BIG SCIENCE QUESTIONS MOTIVATING A SUBDUCTION ZONE INITIATIVE ..................................................................8 2.1 When and Where Do Large Earthquakes Happen? .................................................................................................................................................................8 2.2 How is Mantle Magma Production Connected Through the Crust to Volcanoes? .................................................................12 2.3 How Do Spatial Variations in Subduction Inputs Affect Seismicity and Magmatism? .....................................................15 2.4 How Do Surface Processes Link to Subduction? .....................................................................................................................................................................17 3. THE 4D APPROACH ...........................................................................................................................................................................................................................................................20 4. FRONTIERS ......................................................................................................................................................................................................................................................................................24 5. THE LINK BETWEEN HAZARDS AND FUNDAMENTAL SCIENCE ........................................................................................................31 6. INTERNATIONAL OPPORTUNITIES ......................................................................................................................................................................................................35 7. COMMUNITY INFRASTRUCTURE AND IMPLEMENTATION STRATEGIES ..........................................................................40 7.1 Overarching Infrastructure Strategies ....................................................................................................................................................................................................40 7.2 Physical Infrastructure ...................................................................................................................................................................................................................................................40 7.3 Examples of Implementation ..............................................................................................................................................................................................................................41 7.4 Intellectual Infrastructure .........................................................................................................................................................................................................................................46 8. FRAMEWORK FOR EDUCATION AND OUTREACH AND CAPACITY BUILDING ........................................................51 8.1 Outreach (General Public) ........................................................................................................................................................................................................................................51 8.2 Up-reach (Sponsors, Policymakers, Engineers) .........................................................................................................................................................................52 8.3 In-reach (Within the Academic Community) ................................................................................................................................................................................53 8.4 International Capacity Building .......................................................................................................................................................................................................................54 9. BUILDING THE SZ4D INITIATIVE ...............................................................................................................................................................................................................55 9.1 Building Partnerships with Existing Organizations .............................................................................................................................................................55 9.2 What We Can Do Right Away ...............................................................................................................................................................................................................................55 9.3 The 10-Year Vision ................................................................................................................................................................................................................................................................57 REFERENCES ........................................................................................................................................................................................................................................................................................59 APPENDIX 1. SZO Workshop White Papers .............................................................................................................................................................................................62 BOXES Box 2.1. Investigations of the Tōhoku 2011 Earthquake ....................................................................................................9 Box 2.2. Sampling the Complete Slip Spectrum ................................................................................................................11 Box 2.3. The Timing of Magma Recharge Prior to Eruption............................................................................................13 Box 2.4. Extent of Hydration