1) RCL - the initiation, evolution, and eventual destruction of continent- ocean margins involve the coupled interaction of mechanical, fluid, chemical, and biological processes. These processes result in the accumulation of most of the Earth’s valuable resources and the focusing of the principal geologic hazards at margins; the locus of the greatest population density. The Rupturing of Continental Lithosphere (and birth of an ocean) experiment will proceed by focused investigations of the four-dimensional style, distribution, and depth partitioning of extension within continental lithosphere to determine the spatial and temporal variations in the rheology of the lithosphere, why rifts form where they do, and the forces required to sever continental lithosphere.
2) SubFac - Subduction of oceanic plates causes earthquakes, tsunamis, and explosive volcanism, and also gives rise to ore deposits, geothermal energy, and the continental crust we live on. The Subduction Factory Initiative focuses research on two contrasting subduction zones to address fundamental questions about forcing functions for magmatism and fluid flow, volatile cycles through convergent margins, and mass balance and growth of the continents.
3) SEIZE - Subduction zones also generate the world’s largest and most destructive earthquakes and tsunamis, and host much of the world’s population The Seismogenic Zone Experiment studies the shallow subduction plate interface that is locked and accumulates elastic strain, periodically released in large or great earthquakes. Questions focus on the controls on the distribution of seismic energy release, on the heterogeneities in the locking behavior of the interface, on the rate of propagation and slip rates of earthquakes, and on the nature of temporal changes in strain, fluid pressure and stress during the seismic cycle.
4) S2S - The Source-to-Sink initiative will provide a comprehensive study of linked, terrestrial and marine sediment dispersal systems over the range of time scales for which sedimentary processes operate. Observational, laboratory and theoretical studies will be integrated to allow the modeling of entire, linked sedimentary systems as opposed to only their components. Questions center around the role of changing tectonics, climate and sea level as forcing functions in the production, transport and storage of sediments and solutes; processes initiating erosion and sediment transfer, and their interactions; and the interplay of sedimentary processes and forcing functions in creating the stratigraphic record.
With the maturing of the science plans and implementation proceeding in all initiatives, the MARGINS program can focus more attention on data management and education and outreach. Data policies for the archiving and timely release of MARGINS funded data are now in place and dedicated focus site database design, schema, and template experiments are underway. The MARGINS Office now has a half-time FTE to pursue Education and Outreach activities. Reflecting the strengths of the MARGINS Steering Committee and Office, efforts will focus on undergraduate and informal education. Early activities include the creation of a MARGINS post-doctoral fellowship scheme, a MARGINS Images library for undergraduate instructors, and collaboration with the St. Louis Science Center with the ultimate goal of developing MARGINS related exhibits. All products will be made available to the MARGINS science community for adaptation and use nationwide. Collectively, the formal MARGINS publications, the products of the Education and Outreach efforts, and the databases of the MARGINS focus sites represent an important legacy and resource for future researchers-NSF’s “investment in the future.”