Reservoirs and Fluxes (RF), the first of the four Communities to form, has received another two years of DCO funding beginning April 2013. The award from the Sloan Foundation is intended to promote deep carbon science through seeding scientific networks, improving instrumentation and infrastructure, and engagement of both the scientific community at large and the general public. The proposal, headed by RF chair Erik Hauri (Carnegie Institution of Washington) and co-chair Bernard Marty (CRPG, Nancy), outlines how the community will advance substantially and measurably the qualitative and quantitative understanding of reservoirs and fluxes of Earth’s deep carbon and thus contribute to meeting the decadal goals of the Deep Carbon Observatory (DCO).
The community will focus on five key areas: (1) degassing deep carbon through volcanic processes; (2) degassing deep carbon through tectonic and other diffuse processes; (3) origin, age, and depth of diamonds and mineral inclusions found within them; (4) fluid dynamics of carbon transport in volcanoes and global circulation of carbon from Earth’s surface to its core; and (5) chemical forms, mineral hosts, and reactions of carbon moving between reservoirs, both shallow and deep.
Over the next two years, this funding will allow for the development of both expert research networks and the products their members create. Collaborating with national volcano observatories, the international RF sub-group DECADE (Deep Earth Carbon Degassing) will begin to establish the first global network for direct measurement of volcanic CO2 flux and produce a new database on eruptions and volcanic gases. Another sub-group, DMGC (Diamonds & Mantle Geodynamics of Carbon), will begin assembling an international reference collection of diamonds for research and produce a geochemical database of diamonds and their inclusions. A significant, possibly major, fraction of carbon is degassed from the crust and from the mantle during tectonic processes such as mountain building, crustal extension, faulted areas, the extent of which being largely unknown. To understand these fluxes, the Reservoirs and Fluxes community aims to develop a new effort that will gather scientists from different fields, e.g. basin research, metamorphism, organic geochemistry, and tectonics, and plan to have a startup meeting within a year. The new international science teams researching tectonic fluxes of deep carbon and producing geodynamic models for carbon flux within volcanic systems and from crust to core will lay groundwork of measurements and models later to be used by all Communities of the DCO.
Progress in understanding reservoirs and fluxes of deep carbon should bring both societal and scientific benefit. The surface and deep-Earth carbon cycles meet in areas that encompass some of the most extreme natural hazards on the planet. Volcanic eruptions on continents, ocean islands, ocean ridges, and convergent margins deliver enormous amounts of carbon to Earth’s atmosphere, always passively, sometimes actively, and occasionally catastrophically. On geological time scales, discontinuities in the deep carbon cycle have caused mass species extinction. If volcanoes deliver the breath of deep Earth, then surely its pulse is read in the seismic activity of earthquakes. Great earthquakes signal the slow but steady destruction of tectonic plates at Earth’s convergent margins, a process that continues as deep as one-third of the depth to the core-mantle boundary, dragging carbonated oceanic crust into deep Earth. Yet the balance of delivery and return fluxes of carbon between Earth’s surface and interior is so poorly known that we don’t even know if the net flux of carbon is into or out of deep Earth.
Photo credit: Erupting volcano Yasur In the Vanuatu arc, SW Pacific ocean by Patrick Allard