The American Geophysical Union (AGU) Fall Meeting took place 9-13 December 2013 at the vast Moscone Conference Center in San Francisco, CA, USA. Many of the more than 22,000 Earth and planetary scientists who were present share the Deep Carbon Observatory’s goals.
Deep Energy, Deep Life, and a Host of Press for DCO
The October issue of American Mineralogist featured a paper by Muriel Andreani, Isabelle Daniel, and Marion Pollet-Villard of University Claude Bernard Lyon 1, France, detailing how aluminum can act as an efficient catalyst of the serpentinization reaction. Arguably the most important fluid-rock reaction in our solar system, serpentinization results in the production of molecular hydrogen in conditions of high temperature and pressure, thus providing a source of energy for Earth’s deep biosphere. Media coverage of this story, along with others highlighted in this DCO news release, travelled around the world, with stories appearing in numerous international news outlets such as the BBC, New Scientist, and Le Figaro. DCO’s Isabelle Daniel attended the meeting, presenting this research as a poster on the afternoon of Wednesday, 11 December 2013.
Understanding the chemical and physical properties of water under high temperatures and pressures is crucial when considering reactions such as serpentinization. Until now, theoretical models have been limited to depths of around 15 km. However, work by Dimitri Sverjensky (The Johns Hopkins University, USA) and colleagues resulted in a new Deep Earth Water model that emulates the behavior of water up to 200 km, into Earth’s upper mantle. Sverjensky presented this exciting development on the first day of the meeting. The model is now available for download here.
Tuesday, 10 December 2013, was a big day for Deep Life scientists at AGU 2013, with a series of exciting talks and posters. Matt Schrenk (Michigan State University, USA) spoke to BBC Radio 4’s Inside Science program about the potential origins of life deep underground. Rick Colwell (Oregon State University, USA) took the podium to talk about the most recent data analysis in the Census of Deep Life: DNA taken from 149 sampling sites around the world having been subjected to 16S sequencing (using 454 pyrosequencing). The data so far point to the existence of a core group of 18 bacterial species (archaeal DNA was found at only 56 sites) that have been found at all sites sampled so far, suggesting that global deep biosphere diversity is supported by a ubiquitous community of organisms.
Other DCO Deep Life-focused talks included Barbara Sherwood Lollar (University of Toronto, Canada) emphasizing to the audience that while the marine deep biosphere is a rich and important area for research, Precambrian continental rock represents an enormous potential terrestrial habitat for life. Julie Huber (Marine Biological Laboratory, Woods Hole, USA) and William Brazelton (University of Utah, USA) talked about the effects of extreme pressure and pH, respectively, on life at deep ocean hydrothermal vents.
Other DCO Highlights
A major goal of DCO is promoting innovation in the field of Data Science. On Monday, DCO’s Executive Director Bob Hazen (Carnegie Institution of Washington, USA) discussed how best to approach big data to build new hypotheses. On the subject of “abduction”, the process of forming a logical inference from reliable data to generate a hypothesis, Hazen commented, “these methods represent a path to discovering what we don’t know we don’t know.” Peter Fox, Patrick West, Marshall Ma, and Yu Chen of the DCO Data Science team (based at Rensselaer Polytechnic Institute, USA) presented several talks and posters about information science over the course of the meeting, including three posters that dealt directly with work they are performing for DCO. The Data Science team also staffed a booth in the expansive Exhibitor Hall, with information about DCO Data Science, as well as other projects being conducted at RPI.
Craig Manning (University of California Los Angeles, USA) addressed the meeting on Monday, speaking about the importance of considering the movement of CO2 away from actively degassing volcanoes in fluids when calculating global CO2 flux. Taryn Lopez (University of Alaska Fairbanks, USA) also focused on volcanic degassing, giving a talk on Friday afternoon covering work on three actively degassing volcanoes in Alaska: Mt. Martin, Mt. Magik, and Trident Volcano (part of the Katmai Volcano cluster). Using direct and remote measurements to constrain flux, fluids, and volatiles, preliminary work at Mt. Magik and Trident suggests that an increase in SO2 degassing precedes local earthquakes.
Liz Cottrell (Smithsonian Institution, USA), in her presentation on Wednesday, followed up on her publication from this summer on redox heterogeneity in Earth’s mantle. In an effort to correlate basalt chemistry and seismological measurements, Cottrell and her colleagues sampled across the Australian-Antarctic Discordance and found that variations in the redox state of iron in the mantle correlated with seismic signatures in the same region (more oxidized mantle corresponds to a reduction in shear wave density). These preliminary data are promising, and could help constrain the oxidation state of Earth’s entire upper mantle.
In one of the last DCO talks of the week, Wendy Mao (Stanford University, USA) presented her work imaging high-pressure samples using synchrotron X-ray imaging. Mao and her team are pursuing 2D radiography, 3D tomography, and spectroscopic imaging on the nanoscale at the extreme temperatures and pressures of deep Earth, a technically very challenging experimental goal. Currently, they have in situ data at high pressure but not also at high temperature. One of the questions these experiments will help answer is: How did Earth’s layers form? Preliminary data suggest percolation could be a plausible mechanism for the formation of the core.
DECADE Initiative Town Hall
On Tuesday, Tobias Fischer (University of New Mexico, USA) led a Town Hall meeting to discuss both current and future efforts taking place as part of the Reservoirs and Fluxes DECADE (Deep Carbon Degassing) initiative. DECADE seeks to improve global estimates of volcanic CO2 degassing, with researchers installing new monitoring stations on 25 of the world’s 150 most actively degassing volcanoes.
Fischer began the Town Hall by providing the more than 50 people in attendance with some background on the initiative, and a reminder that the abstract deadline for the 12th CCVG-IAVCEI Field Workshop on Volcanic Gases (Northern Chile, 17-25 November 2014) is April 2014. He also emphasized that while DECADE will implement new monitoring stations around the world, capitalizing on existing monitoring capabilities already in place is very important.
Brendan McCormick (Smithsonian Institution, USA) described to the group the database he and colleagues have been developing to efficiently handle all of the data produced through the DECADE initiative. The design structure has now been defined, and will be hosted by EarthChem/IEDA, in collaboration with Kerstin Lehnert (Lamont-Doherty Earth Observatory, USA), to ensure data are integrated and accessible to the global volcanic degassing community.
A lively discussion followed in the question and answer period, centering around potential field sites for future instrumentation deployment as well as initiating collaborations with atmospheric and space scientists to make use of satellites such as GOSAT to verify terrestrial volcanic degassing measurements.
Extreme Physics and Chemistry Pre-AGU Workshop
[Report contributed by Dimitri Sverjensky]
The Extreme Physics and Chemistry (EPC) Workshop took place on 7 December 2014 at Stanford University, CA, USA. The 42 participants were treated to twenty-one talks each of fifteen minutes, four scheduled discussion periods throughout the day, and eight posters. All of this proceeded in a very open atmosphere involving many questions and interactions.
“Everyone…agreed that it was a remarkably interesting meeting that greatly helped an increased understanding of what the EPC community was doing as it enters a new two year funding period,” said EPC Steering Committee Member and Engagement Liaison Dimitri Sverjensky (The Johns Hopkins University, USA).
A major theme of the workshop turned out to be the discovery of unexpected species and unexpected types of bonds involving carbon and other elements. Highlights included the experimental demonstration by Sergei Lobanov and co-workers from the Carnegie Institution of Washington of a rich variety of complex polymerized hydrocarbon compounds at pressures greater than about 25 GPa and temperatures greater than 1,500 K. Sverjensky and colleagues at JHU found an unexpected range of oxidation states of aqueous carbon-species at the lower pressure conditions of the upper mantle. Ziming Yang and co-workers from Arizona State University, USA, described new insights into the reaction mechanisms of aromatic hydrocarbons under crustal hydrothermal conditions, and found an extraordinary correspondence with the results of photochemical experiments under ambient conditions.
Hummer and co-workers at UCLA, USA, described a novel set of experiments in which they analyzed synchrotron X-ray scattering data and found complex polymerization behavior of silicon in melts involving mixtures of carbonate and silicate at three to six GPa. Complementary theoretical studies by Razvan Caracas and colleagues at the CNRS, Lyon, France showed a complex dependence of the development of –CO4 groups in magnesium-carbonate-silicate mixtures at pressures of 130 GPa. Matthew Armentrout and colleagues from UC Davis reported direct silicon-carbon bonds associated with the substitution of carbon for oxygen in magnesium silicate compounds. Lucio Merlini et al. of the University of Milan, Italy, reported new carbonate structures at extreme pressures of 130 GPa.
DCO Tectonic Fluxes Workshop
[Report contributed by Olivier Beyssac and Jay Ague]
Just before the AGU fall meeting 2013, the DCO sponsored a workshop on “Tectonic Fluxes of Carbon” held on Sunday December 8th 2013 at the San Francisco Marriott Marquis. The workshop was co-organized by Jay Ague (Yale, USA) and Olivier Beyssac (CNRS IMPMC Paris, France), and was attended by nearly 50 researchers representing 8 countries. This full day of discussion was organized around three scientific sessions entitled “Carbon Cycle and C-bearing fluids and minerals,” “Deep carbon in orogens,” and “Low-temperature carbon cycling.” Each session was moderated by a discussion leader, and included three keynotes by leading scientists in the domain (program below). During lunch, a poster session allowed the participants to present their own research.
Session I Carbon Cycle and C-bearing fluids and mineralsKeynote 1: Joshua West (USC) Carbon cycling and modelingKeynote 2: Nadia Malaspina (Milano Bicocca) COH fluids and redox; field and experimental perspectivesKeynote 3: Matthieu Galvez (Carnegie Institution of Washington): Carbon mobility in the lithosphereDiscussion led by Doug Rumble (Carnegie Institution of Washington)Session II Deep carbon in orogensKeynote 4: Peter Kelemen (Columbia) Carbon cycling in subduction zones: Perspectives from field observations in Oman, Santa Catalina, and SambagawaKeynote 5: Yuji Sano (Hiroshima University) Carbon in faulted-seismogenic areasKeynote 6: Giovanni Chiodini (INGV Naples): Measurement of CO2 fluxes at the orogen scaleDiscussion led by Olivier Beyssac (IMPMC Paris) and Jay Ague (Yale)Session III Low-temperature carbon cyclingKeynote 7: Christian France-Lanord (CRPG) Carbon fluxes during erosion/alterationKeynote 8: Brian Horsfield (GFZ – Potsdam) Carbon in basins, diagenesisKeynote 9: Kate Maher (Stanford): Carbon cycling in the shallow crustDiscussion led by Page Chamberlain (Stanford): Research directions, including field areas, collaborative proposals, and possible field trips to study orogenic carbon cycling.
The workshop covered potentially all non-volcanic carbon fluxes affecting Earth’s lithosphere. The lithosphere occupies a key position in the carbon cycle; at the interface between the exosphere (atmosphere, oceans, biosphere) and Earth’s deep interior. Part of the discussion was dedicated to specific carbon fluxes during major geological processes, such as erosion, subduction, and non-volcanic degassing in orogens or faulted areas. Global quantification of these fluxes remains in its infancy, and we have a poor knowledge of the geochemical processes beyond these fluxes affecting both organic and inorganic carbon. Clearly, more dedicated field studies and measurement campaigns are needed, and various field targets were identified including the Himalayas and the Apennines/Western Alps/Corsica systems. Modeling aspects were also discussed, from global modeling of the carbon cycle to thermodynamic modeling of graphite formation during fluid-rock interactions, through modeling of carbon mobility at Earth’s surface during erosion or in sedimentary basins. Altogether, it appears that research into the “Tectonic Fluxes of Carbon” absolutely requires integrated multidisciplinary studies with different spatial and temporal scales of observation.
Looking Ahead to AGU 14
No report can do justice to one of the largest scientific conferences in the world. Several other organizations have summarized the meeting from their perspective, including Earth Magazine and The Guardian.
And if you attended the meeting but missed out on a session or two, there is an archive of recorded talks on the AGU website: virtual options.
It is a testament to the diversity of DCO that our community was represented in such an incredible variety of sessions (a full record of talks, posters, and town halls from this year’s meeting can be found here).
All photos taken by Katie Pratt (Univeristy of Rhode Island, USA) unless otherwise indicated.