Volatiles and Fluids in Subduction Zones

SFB574 Retreat 2011

On September 7 and 8, 2011, the collaborative research program SFB 574 “Volatiles and fluids in subduction zones” held its 10th retreat at the Akademie Sankelmark near Flensburg. Founded in 2001, the SFB research focused on the Central American subduction zone, changing to the southern Chilean subduction system in 2007. The SFB will be concluded mid-2012. Therefore, the major task for the 42 participating scientists (including James B. Gill, USA, Lucia Villar, Chile, and Andrea Anasetti, Italy, as visiting guests) at this workshop was to discuss the integration of the research results obtained by the 12 projects with emphasis on comparing the Chilean and Central American subduction systems.
On the first day, each project presented their scientific developments, followed by a general assembly of SFB members to discuss organizational issues such as the SFB data base and preparation of concluding activities in 2012. A general discussion on the second day identified overarching research topics that provide the opportunity to combine results from different projects and that advance the understanding of how subduction zones operate. Subsequently separate groups gathered to discuss these topics in depth in preparation for scientific publications. These topics address the following questions: How do the various input and output fluxes of volatiles and fluids balance under different geometric and dynamic subduction conditions? What are the relationships between the intensity of hydration of the subducting plate as it bends into the subduction zone, and the rate of dehydration as the subducted slab progresses to greater depths, for the different geometries and thermal structures along the Chilean and Central American subduction zones? Which global implications can be derived from the different processes and rates of dewatering through the continental slope at Central America and Chile? While addressing basic scientific questions, all these topics also have practical aspects, because the answers will improve the understanding of how, and how frequently, natural hazards such as large earthquakes, submarine landslides, tsunamis and explosive volcanic eruptions occur.
Based on the discussions during this retreat, the answers to these questions will be elaborated during the coming months and will form the scientific contents of a compilation of SFB research to be published in 2012.