Recent Findings

A chronostratigraphic assessment of the Moenave Formation, USA using C-isotope chemostratigraphy and detrital zircon geochronology: Implications for the terrestrial end Triassic extinction
Suarez, Celina;Knobbe, Todd K.;Crowley, James L.;Kirkland, James I.;Milner, Andrew R.C. Earth and Planetary Science Letters, (2017). DOI:10.1016/j.epsl.2017.07.028. Publication Metadata

A reliable and effective methodology to monitor CO 2 flux from soil: The case of Lipari Island (Sicily, Italy)
Lelli, Matteo ;Raco, Brunella Applied Geochemistry, (2017). DOI:10.1016/j.apgeochem.2017.08.004. Publication Metadata

Abundant carbon in the mantle beneath Hawai‘i
Anderson, Kyle;Poland, Michael P Nature Geoscience, (2017). DOI:10.1038/ngeo3007. Publication Metadata

Dated eclogitic diamond growth zones reveal variable recycling of crustal carbon through time
Timmerman, Suzette;Koornneef, Janne;Chinn, Ingrid;Davies, Gareth Earth and Planetary Science Letters, (2017). DOI:10.1016/j.epsl.2017.02.001. Publication Metadata

Deep mantle: Enriched carbon source detected
Barry, Peter Nature Geoscience, (2017). DOI:10.1038/ngeo3001. Publication Metadata

Geochemical constraints on volatile sources and subsurface conditions at Mount Martin, Mount Mageik, and Trident Volcanoes, Katmai Volcanic Cluster, Alaska
Lopez, Taryn;Tassi, Franco ;Aiuppa, Alessandro;Galle, Bo;Rizzo, Andrea Luca;Fiebig, Jens ;Capecchiacci, Francesco;Giudice, Gaetano ;Caliro, Stefano ;Tamburello, Giancarlo Journal of Volcanology and Geothermal Research, (2017). DOI:10.1016/j.jvolgeores.2017.09.001. Publication Metadata

Heterogeneity in mantle carbon content from CO2-undersaturated basalts
Le Voyer, Marion;Kelley, Katherine;Cottrell, Elizabeth;Hauri, Erik Nature Communications, (2017). DOI:10.1038/ncomms14062. Publication Metadata

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Projects

Carbon Footprint of Hawaiian Hotspot Volcanoes - Mauna Kea volcano, Hawaii

Project Investigators: Hauri, Erik

Start Date: 2012-02-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions from the five active Hawaiian volcanoes (Loihi seamount, Kilauea, Mauna Loa, Mauna Kea and Hualalai) to determine the sources and fluxes of volatiles through the volcanic construction above the Hawaiian hotspot.

Details...

Carbon Footprint of Hawaiian Hotspot Volcanoes - Mauna Loa volcano, Hawaii

Project Investigators: Hauri, Erik; Trusdell, Frank ; Marske, Jared

Start Date: 2012-02-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions from the five active Hawaiian volcanoes (Loihi seamount, Kilauea, Mauna Loa, Mauna Kea and Hualalai) to determine the sources and fluxes of volatiles through the volcanic construction above the Hawaiian hotspot.

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Carbon Inventory of Oceanic Basalts

Project Investigators: Kelley, Katherine; Hauri, Erik; Cottrell, Elizabeth; Le Voyer, Marion

Start Date: 2012-02-01

End Date: 2020-01-01

Summary: DCO Fellow Marion Le Voyer (DTM/Smithsonian) and GSO graduate student Marion Lytle involved in this project began their work in early 2012.  Le Voyer has obtained data on CO2, H2O and other volatiles in a global collection of over 400 mid-ocean ridge volcanic glasses that have been already well-characterized for trace elements by another group (Jenner & O'Neill, 2012), and a suite of previously unreported volatile-rich popping rocks from the equatorial Mid-Atlantic Ridge.  Lytle has obtained similar data on a suite of 60 back-arc basin ridge glasses from the Lau Basin that complement the data set on ~100 glasses analyzed from other back-arc ridges by PI Kelley.  Together these sample suites comprise the first-ever global data set for CO2 emerging from ocean ridge volcanism.  Because the thickness of the crust, and the spreading rate, is already known along the global ocean ridge system, these measurements, combined with trace element data, translate directly into a flux for the most voluminous magmatic system on Earth.  Several publications have already appeared in the literature, one more is in revision, and another is in preparation.  Ultimately, this data will be used to visualize the variability of the magmatic CO2 flux along the entire 44,000 km length of the global ocean ridge system.

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Carbon Storage and Partitioning in Upper Mantle Silicate Minerals

Project Investigators: Hirschmann, Marc; Hauri, Erik; Rosenthal, Anja; Novella, Davide

Start Date: 2011-04-01

Summary:

Carbon is present in the upper mantle, but its distribution in silicate minerals and behavior during melting are not well known. We are undertaking high-pressure experiments (piston cylinder) on 13C-doped silicate melts in order to constrain quantitatively the behavior of carbon during silicate melting.

Experimental work at the University of Minnesota focused on the solubility of carbon in mafic silicate melts, and the growth of mantle minerals in 13C-doped silicate melt, using graphite inner capsules sealed within Pt outer capsules.  Experiments have yielded crystals large enough for NanoSIMS measurements of C content with detection limits for 13C ~0.007 ppm.  Analysis of the data on minerals and melts indicates very low C contents within all silicate minerals, but is suggestive of systematic differences in C content between Ca-rich and Ca-poor pyroxenes, as well as increases in C storage capacity in nominally carbon-free silicate minerals with increasing pressure.

 

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DECADE - CO2 Gas Emissions from Merapi Volcano, Indonesia

Project Investigators: Bani, Philipson ; Allard, Patrick; Moussalam, Y. ; Subandriyo , J. ; Sumarti, Sri ; Di Napoli, Rossella

Start Date: 2014-08-21

End Date: 2014-09-16

Summary: First combined OP-FTIR, MultiGAS, SO2-cam and DOAS measurements of gas (including CO2) emissions from Merapi andesitic arc volcano during a post-paroxysmal reawakening phase following the 2010 eruption. Assessment of magma degassing budget normalized to melt inclusion data.

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DECADE - CO2 Soil Degassing at Piton de la Fournaise

Project Investigators: Allard, Patrick; Liuzzo, Marco ; Ferrazzini, Valerie ; Di Muro, A.

Start Date: 2013-01-01

End Date: 2014-12-20

Summary: First systematic prospection and mapping of diffuse CO2 soil degassing from Piton de la Fournaise volcanic edifice, coupled with soil CO2 flux measurements and carbon-helium isotopic determinations. Recent set up of 2 permanent CO2 flux monitoring stations.

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DECADE - Carbon Footprint of a Passively Degassing Volcano

Project Investigators: Fischer, Tobias; Blackmon, Keith ; McMurtry, Gary; Kelly, Peter ; Ramirez Umaña, Carlos José; Hilton, David; Doukas, Michael ; Werner, Cynthia; Clor, Laura; Kulongoski, Justin

Start Date: 2011-05-01

End Date: 2013-12-31

Summary:

The aim of the award was to determine the carbon footprint of one passively degassing volcano as a means to evaluate how mantle-derived carbon is partitioned between direct degassing through high-temperature vents and diffuse gas loss via groundwater systems. Lassen Volcano was selected because it is located on an active subduction zone and has both high-temperature vents as well as an extensive groundwater system accessible by wells. A combination of public supply wells and private (household or domestic) wells throughout the Lassen catchment were sampled for CO2, He-isotopes and gas chemistry. Groundwaters were collected from a total of 42 wells. The region of Lassen Peak also has numerous high-temperature degassing vents, and these localities were sampled for He, CO2, and gas chemistry. Using airborne (helicopter) techniques, we measured a cross section of the CO2 and H2S-rich gas plume emitted from the Bumpass Hell hydrothermal area.

 

Estimates of the magmatic CO2 flux for Lassen are ~3.5 x 107 kg/yr which has been increased to ~4.3 x 107 kg/yr if the Hat Creek-Rising River-Crystal Lake region is added. At face value, therefore, our helicopter-based measurements imply that Bumpass Hell represents ~3.4% of the total magmatic CO2 flux at Lassen. More significant, however, is the observation that if our estimate of the groundwater-borne magmatic CO2 load is correct, then ~26% of the total magmatic CO2 flux ( = 5.8 x 107 kg/yr) enters the groundwater system(s) and is carried away from the summit degassing regions. In this way, ~74% of the true magmatic CO2 flux at Lassen is obtained by using various techniques (e.g., remote sensing) that measure fluxes targeting direct-venting sites – located at or close to the volcano summit. The question now posed is the general applicability of these observations to other volcanoes worldwide used in deriving CO2 flux estimates from the solid Earth.

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DECADE - Degassing at Lascar and Lastarria Volcanoes

Project Investigators: Hansteen, Thor

Start Date: 2012-11-01

End Date: 2015-12-31

Summary: Lascar and Lastarria are at the present two of the most active persistently degassing volcanoes in North Chile. In cooperation with the Chilean volcano observatory (OVDAS), we measure semi-continuous time series of SO2 fluxes using permanent scanning Mini-DOAS stations at Lascar. Campaign work including scanning Mini-DOAS and MultiGas measurements were performed in 2012 and 2013. We combine and correlate degassing data with seismic and chemical data.

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DECADE - Degassing at Villarrica and Llaima Volcanoes

Project Investigators: Hansteen, Thor

Start Date: 2010-03-01

End Date: 2014-12-31

Summary: The neighboring volcanoes Villarrica and Llaima are at present two of the most active persistently degassing volcanoes in Chile, and have produced 60 and 50 historical eruptions, respectively. Villarrica volcano activity is characterized by recurrent, mildly strombolian activity and continuous degassing from a permanent lava lake within the summit crater, pressent since it last erupted in 1984/85. In contrast, Llaima volcano exhibits constant fumarolic activity since the most recent eruption, which ended in 2009. In cooperation with the Chilean volcano observatory (OVDAS), we measure semi-continuous time series of SO2 fluxes using permanent scanning Mini-DOAS stations. We combine and correlate degassing data with seismic and chemical data.

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DECADE - Evaluation of Extant and Emerging Satellite-Based Remote Sensing Technology for Quantifying Volcanic CO2 Emissions

Project Investigators: Andrews, Benjamin ; Schwandner, Florian M; Chance, Kelly ; Popp, Christoph; Cottrell, Elizabeth

Start Date: 2012-01-01

Summary:

Direct satellite measurements of volcanic CO2 released during the explosive eruption of Mount Kasatochi (USA) in August 2008 reveal CO2 in excess of background, and satellite-based CO2/SO2 ratios result in a best estimate of total CO2 mass ejected of 12-56 Tg. Extrapolating these numbers results in 8-39 Tg/y total global CO2 emissions from explosive volcanism. Our results therefore demonstrate the capability of current satellite instruments to detect and quantify CO2 emissions from eruptions with relatively large gas output and suggest that explosive volcanism contributes substantially to subaerial volcanic CO2 emissions.

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DECADE - Gas Chemistry at Poas Volcano, Costa Rica

Project Investigators: Fischer, Tobias

Start Date: 2014-04-01

End Date: 2017-07-01

Summary: The chemical and isotopic composition of fumarole gas discharges were collected at Poás Volcano, Costa Rica from 2001 to 2014, covering a period during which the volcano experienced a series of phreatic eruptions (2006 to present).  The relative abundances of Poás C-S-H-O gas species are controlled by reactions involving the SO2-H2S and So – SO2 gas buffers indicating magmatic temperatures of up to 800°C.  Although fumarole outlet temperatures are < 120°C for most samples, SO2 is the dominant sulfur gas and HCl contents are relatively high.  Gas compositional changes within the magma-lake-hydrothermal system likely result from a combination of several processes, including: 1) The injection of new and undegassed magma in late 2000 – early 2001, 2) the heating of the hydrothermal system, accompanied by gas pressure build-up, and 3) hydrofracturing through 2006. These processes culminated in the phreatic eruptions of 2006 and 2008. Since 2005, the lake level has declined and is now (2014) at the lowest level (10 m) since the last period that it dried out completely (1989 -1994).  The most recent data of 2014 show a high level of degassing from the dome fumaroles, and the release of HCl – rich and CO2-poor gases implies that the magma injected in late 2000 continues to supply volatiles. Time series sampling of fumarole gases provides important insights to better understand magmatic and hydrothermal processes at active volcanoes and also to potentially forecast phreatic eruptions.  In addition, these data provide valuable insights into CO2 content variations at active volcanoes and that carbon can be controlled by the sulfur buffer system.

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DECADE - Gas Composition at Cerro Negro Volcano, Nicaragua

Project Investigators: Roman, Diana; Fischer, Tobias; Stix, John; La Femina, Peter

Start Date: 2013-03-01

End Date: 2017-12-01

Summary: A time series gas sampling program has been started at Cerro Negro Volcano, Nicaragua, initiated through a PASI NSF workshop in 2013 (Six and La Femina were organizers).  Samples are collected in collaboration with INETER, who are also being trained to continue the sampling program.  Cerro Negro is notorious for its violent explosive activity that often occurs without any warning.  Cerro Negro is a basaltic volcano. Gas samples from this locality are reduced in character and provide important insights into the origin of reduced carbon species such as CO.

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DECADE - Gas Composition of Oldoinyo Lengai, Tanzania

Project Investigators: de Moor, Maarten; Fischer, Tobias; Burnard, Pete; Marty, Bernard; Lee, Hyunwoo

Start Date: 2014-06-01

End Date: 2017-12-01

Summary: Oldoinyo Lengai is the world's only currently active carbonatite volcano.  It is also a large emitter of CO2 and allows the access to pristine mantle derived gases in a continental rift setting.  Therefore, it is an extremely valuable geochemical window into Earth's interior and in particular into Earth's subcontinental mantle.  Oldoinyo Lengai usually erupts effusive carbonatite lava.  In 2007, an explosive eruption occurred producing several km high nephelinite ash columns.  A large pit crater formed as a result of the eruption.  Since then carbonatite has been erupting at the bottom of the pit crater.  CO2 emissions from Oldoinyo Lengai have not been quantified since 2009, but appear to remain significant.  Gas samples were collected on four occasions: in 2005, 2006, 2009, and 2014.  In 2014 soil gas emissions were measured in the crater.

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DECADE - Malumalu Seamount, American Samoa

Project Investigators: Hauri, Erik; Jackson, Matthew

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O, and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

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DECADE - Mangaia, Cook Islands

Project Investigators: Hauri, Erik; Jackson, Matthew

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

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DECADE - Muli seamount, American Samoa

Project Investigators: Jackson, Matthew; Hauri, Erik

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Ofu, American Samoa

Project Investigators: Hauri, Erik; Jackson, Matthew

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Savaii, Western Samoa

Project Investigators: Jackson, Matthew; Hauri, Erik

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Tahaa, French Polynesia (A)

Project Investigators: Hauri, Erik; Jackson, Matthew

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Tau, American Samoa

Project Investigators: Hauri, Erik; Jackson, Matthew

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

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DECADE - Terceira Island, Azores Archipelago

Project Investigators: Chiodini, Giovanni; Silva, Catarina; Viveiros, Fatima; Hipólito, Ana Rita; Ferreira, Teresa ; Cardellini, Carlo; Zanon, Vittorio ; Caliro, Stefano

Start Date: 2014-07-24

End Date: 2014-10-15

Summary: This project is inserted in the DECADE initiative of the DCO and intends to improve the knowledge about CO2 volcanic emissions in Terceira Island, where very little is known about the secondary manifestations of volcanism. The only fumarolic field found in the island is located in the central part of the island, where the NW-SE periodically active basaltic fissure zone intersects the dormant volcanic structure of Pico Alto. Integration of gas geochemical (soil degassing, fumarolic fields), structural, and petrological data (fluid inclusions) will contribute not only to estimate the CO2 released in this volcanic area, but also to understand the origin of the volatiles trying to follow the path from depth until surface. To accomplish these objectives, we will carry out extensive field surveys at Terceira Island to sample gas released from soils and from the fumarolic emissions, as well as collect adequate rock samples to perform fluid inclusions studies. At the same time as the soil CO2 flux measurements, we will collect gas samples to measure carbon isotopic compositions based on the accumulation chamber method. In addition, modeling of the soil CO2 flux variations in the permanent CO2 flux station installed at Furnas do Enxofre fumarolic field will contribute to identifying external factors (e.g., meteorological) that may interfere with the CO2 emission, as well as recognize daily and seasonal variations which were already observed in other degassing areas of the Azores archipelago. Terceira Island may thus be used as a test site to integrate different methodologies that can be extrapolated to other degassing areas.

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DECADE - The Carbon Footprint of a Passively Degassing Volcano

Project Investigators: Werner, Cynthia; Franz, Brian ; Hilton, David; Kulongoski, Justin ; Fischer, Tobias

Start Date: 2011-04-01

Summary:

Carbon is degassed from active volcanoes prior to and during magmatic eruptions, but it has been recently discovered that magmatically inactive volcanoes may degas a significant amount of C passively. We are studying the carbon concentration of groundwater in several locations surrounding Lassen Peak in order to determine the extent to which deep carbon may be degassed into the water table surrounding a passively degassing volcano. Lassen Volcano was selected because it is located on an active subduction zone and has both high-temperature vents as well as an extensive groundwater system accessible by wells.

 

Groundwaters: A combination of public supply wells and private (household or domestic) wells throughout the Lassen catchment were sampled for CO2, He-isotopes and gas chemistry. Groundwaters were collected from a total of 42 wells.The distribution of sampling points within a 60 km radius of Lassen Peak is given in the figure (left). 3He/4He ratios (R) > the atmosphere values (RA) indicate the presence of mantle-derived He throughout the region. This is consistent with widespread dispersal of magmatic volatiles from the volcanic system.

 

It is important to note that dissolved CO2 in groundwater is composed of different end members. Our measurements of dissolved inorganic carbon (DIC) can be corrected to "external" carbon by subtracting the carbonate-derived carbon obtained through the water chemistry. We determined the water chemistry for all groundwater samples and used a simple mixing model to resolve external carbon into organic and endogenic (deep or mantle) CO2, assuming fixed isotope and concentration characteristics.

 

Using this approach, we find that between 2% and 74% (average = 31±19%) of the total DIC is composed of endogenic CO2. Thus, using our measurements of total DIC, we can calculate the median concentration of endogenic CO2 in groundwaters of the catchment ~ 7 x 10-4 moles/L.

 

Extensive studies have been carried out on groundwater fluxes in the Lassen region with cold water flow rates estimated at ~8000 L/s (excluding Hat Creek region and eastern Lassen). This value yields an endogenic CO2 flux of 7.8 x 106 kg/yr. Adding this value to prior estimates of Hat Creek (7.6 x 106 kg/yr) gives a total groundwater endogenic CO2 flux of ~ 1.5 x 107 kg/yr.

 

Thirty groundwater samples were analyzed for gas chemistry and almost all samples are dominated by N2. CO2 contents range from 1% to 99.6% with the majority of samples between 5% and 25% CO2. The highest CO2 contents are found at significant distances from the crater (~30 km). CH4 ranges from 0 to 8.6%. The average CH4/CO2 is 0.22 for groundwaters resulting in a CH4 flux of 3.3 x106 kg/yr (using 1.5 x 107 CO2 flux). Therefore, although the high temperature areas dominate total C emissions from Lassen, in terms of CO2, the ground water flux of CH4 dwarfs the high temperature CH4 flux by six orders of magnitude.

 

High-T Vents:  The region of Lassen Peak has numerous high-temperature degassing vents, and these localities were sampled for He, CO2 and gas chemistry.

 

The He-CO2 systematics clearly show the distinction between HT volatiles and groundwaters. The HT vents emit volatiles with arc-like He-CO2 characteristics.

 

Thirteen gas samples collected at the high-temperature sites were analyzed for chemistry. Samples are dominated by CO2 (87-97 mol% dry gas with one at 53%). CH4 ranges from 4 x10-5 to 0.007 mol% dry gas. The average CH4/CO2 is 1.6 x10-7, which results in a CH4 flux of 7 kg/yr (using 4.3 x107 CO2 flux). 

 

CO2 Flux Measurements: Using airborne (helicopter) techniques, we measured a cross section of the CO2 and H2S-rich gas plume emitted from the Bumpass Hell hydrothermal area. When combined with our measured wind speed (5.8 m/s), and the CO2/H2S ratio of the gases, the results indicate that Bumpass Hell emits about 4 metric tons per day (T/d) or 1.5 x 106 kg/yr of CO2 and 0.2 (T/d) H2S. 

 

CO2 Mass Balance: Estimates of the magmatic CO2 flux for Lassen are ~3.5 x 107 kg/yr, which has been increased to ~4.3 x 107 kg/yr if the Hat Creek-Rising River-Crystal Lake region is added. At face value, therefore, our helicopter-based measurements imply that Bumpass Hell represents ~3.4% of the total magmatic CO2 flux at Lassen.

 

More significant, however, is the observation that if our estimate of the groundwater-borne magmatic CO2 load is correct, then ~26% of the total magmatic CO2 flux ( = 5.8 x 107 kg/yr) enters the groundwater system(s) and is carried away from the summit degassing regions. In this way, ~74% only of the true magmatic CO2 flux at Lassen is obtained by using various techniques (e.g., remote sensing) which measure fluxes targeting direct venting sites – located at or close to the volcano summit. The question now posed is the general applicability of these observations to other volcanoes worldwide used in deriving CO2 flux estimates from the solid Earth

 

The volcano mass spec (V-café) was deployed in the Lassen HT area and CO2, N2, Ar abundance data were collected continuously for 72 hours. CO2/N2 ratios measured are an order of magnitude lower than those of collected gas samples indicating significant mixing with air.

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DECADE - Tubuai, Cook Islands

Project Investigators: Hauri, Erik; Jackson, Matthew

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Tutuila, American Samoa

Project Investigators: Jackson, Matthew; Hauri, Erik

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Upolu, Western Samoa

Project Investigators: Jackson, Matthew; Hauri, Erik

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions to determine the sources and fluxes of volatiles through the volcanic construction above this hotspot volcano.

Details...

DECADE - Volcanic CO2 Emissions from the Vanuatu Arc

Project Investigators: Bani, Philipson ; Peters, Nial ; Carn, Simon ; Oppenheimer, Clive; Allard, Patrick

Start Date: 2014-08-05

End Date: 2014-08-21

Summary: The project goal is to improve estimates of volcanic CO2 emissions from actively degassing volcanoes in the Vanuatu island arc. Specific project objectives are to quantify CO2/SO2 ratios and SO2 emission rates, and derive CO2 emission rates in plumes from Gaua and Aoba volcanoes (Vanuatu). Gaua and Aoba are known to be strong sources of volcanic SO2 but to date their CO2 emissions remain unquantified. Proposed activities include fieldwork at Gaua and Aoba volcanoes (Vanuatu), during which we will conduct remote sensing (Fourier-Transform Infrared (FTIR) and ultraviolet spectroscopy) and in-situ measurements of volcanic gas composition. The collected ground-based data will also be used to validate satellite measurements of SO2 emissions. Expected products include new measurements of CO2/SO2 ratios, SO2 emission rates and CO2 emission rates from active volcanoes in the Vanuatu arc.  Expected outcomes include improved constraints on volcanic CO2 emissions in Vanuatu, location of some of the world’s strongest sources of volcanic degassing, and hence improved understanding of global volcanic CO2 emissions.

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DECADE - Volcanic Carbon Atmospheric Flux Experiment

Project Investigators: Fischer, Tobias; McMurtry, Gary; Sutton, Jeff; Dasilveira, Luis

Start Date: 2014-07-12

End Date: 2014-07-20

Summary: Ongoing field tests of the VGAM (Volcanic Gas Analytical Monitor) at Kilauea Volcano.  This visit tested various new water vapor traps and a new solar-powered battery system.  Our target gas is carbon dioxide, but we will also evaluate the other air gases and any sulfur gases detected simultaneously. The VGAM, when used with a portable weather station, can compute fluxes of volcanic gases.

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DECADE - Volcanic Plume Measurements at Mount Etna

Project Investigators: Giudice, Gaetano ; Liuzzo, Marco ; Aiuppa, Alessandro

Start Date: 2015-07-01

End Date: 2015-09-30

Summary: The chemical composition of Etna's plume is monitored by a network of permanent MultiGAS instruments for accurate retrieval of CO2/SO2 ratios in the plume, and calculation of the CO2 output (after combination with UV sensed SO2 fluxes). We also regularly conduct discrete measurement campaigns.

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DECADE- Tahiti, French Polynesia

Project Investigators: Hauri, Erik

Start Date: 2012-01-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions. The research goal is to determine the sources of fluxes and volatiles through the volcanic construction above this hotspot volcano.

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DMGC - The Origin of Ferropericlase included in Diamonds: Shallow or Deep Mantle Origin?

Project Investigators: Schiazza, Mariangela; Reali, Riccardo ; Nestola, Fabrizio; Nimis, Paolo; Hutchison, Mark T

Start Date: 2012-11-01

End Date: 2014-11-01

Summary: Principal Investigator Paolo Nimis, University of Padova, Italy, and co-PIs (Fabrizio Nestola, University of Padova; Mariangela Schiazza, postdoc, University of Padova; Riccardo Reali, graduate student, University of Padova; and Mark Hutchison, Trigon GeoServices Ltd.) are investigating Ferropericlase-bearing diamonds from Juina (Brazil) through in-situ single-crystal X-ray diffraction to obtain information on the orientation of the inclusions relative to their host diamonds and on the pressure of formation to determine formation depths and information about origin.

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Development of Laser Isotope Ratio-meter (LIR) for Volcanic Field Deployment

Project Investigators: Weidmann, Damien

Start Date: 2014-05-01

End Date: 2015-06-30

Summary:

This project is a major step in developing a miniature portable system for carbon isotopic analysis in harsh volcanic environments. It is being funded with DCO instrumentation funding following its endorsement at the September 2013 DCO Volcanic Gas Instrumentation Workshop.

The project goal is to demonstrate a novel laser isotope ratio-meter (LIR) operating in volcano field areas and ultimately to deploy unattended, autonomous, miniature LIRS that produce high-quality, real time, streaming data on the isotopic composition of CO2 in volcanic gases and determination of fluxes using transport data.

Activities will include preparation of an existing prototype instrument for volcanic field operation, validation of the instrument and field protocols, and deployment in field tests in the Naples, Italy area.

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Diamonds and Mantle Geodynamics of Carbon (DMGC Organization)

Project Investigators: Walter, Michael; Pearson, Graham; Shirey, Steven

Start Date: 2013-04-01

Summary: Natural diamonds are direct samples of carbon from Earth’s mantle and directly record the deep carbon cycle back through geologic time. We seek to establish a new international infrastructure for diamond research to advance studies of natural diamonds and experiments on diamond-forming fluids/melts for the understanding of carbon mobility in Earth’s mantle.

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Disko Island as a Test-bed for Carbon Pathways

Project Investigators: Cockell, Charles; Jones, Adrian; Fox-Powell, Mark; Bryce, Casey; Mikhail, Sami; Steele, Andrew; Cousins, Claire

Start Date: 2013-08-05

End Date: 2013-08-13

Summary:

A team of four scientists—P.I. Dr. Claire Cousins, Dr. Sami Mikhail, and PhD students Casey Bryce and Mark Fox-Powell—spent two weeks in August of 2013 sampling basalts and thermal spring materials on Disko Island, Greenland. The primary goal of this work was to collect a robust sample set to support ongoing research of interest to the DCO community.

Disko presents an ideal field site due to its unusual basalts, whose compositions are rare for surface samples, containing FeNi alloys and Fe-carbides. Study of these basalts may lead to increased understanding of their formation. Additionally, Disko is home to many understudied deep thermal springs, including mud volcanoes, salt springs, and cold to warm springs. The investigation of the microbes within these thermal springs may provide insights into subsurface microbiological communities’ carbon pathways and life cycles.

Due in part to its remote location, Disko Island is relatively under-examined. Many of the logistical issues addressed by this team will be invaluable to researchers coming to the island for future study.

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Dziani Dzaha

Project Investigators: Ader, Magali; Cadeau, Pierre ; Bard, Edouard ; Jovovick, Ivan ; Leboulanger, Christophe; Gerard, Emmanuelle; Bouvy, Marc; Rouchon, Virgile; Milesi, Vincent; Debure, Mathieu ; Jézéquel, Didier ; Virgone, Aurelien ; Gaucher, Éric C.; Marty, Nicolas ; Capano, Manuela ; Sarazin, Gérard ; Grossi, Vincent

Start Date: 2014-04-01

End Date: 2014-11-01

Summary:

In April 2014, a French research expedition, led by Magali Ader of the Institut de Physique du Globe de Paris, made its first of four planned field expeditions to the Dziani Dzaha lake to begin characterizing the physical chemistry and biology of the lake during different seasons. This crater lake is located in the Comoros Archipelago, a small volcanic hotspot chain in the Indian Ocean between Madagascar and Mozambique. Dziani Dzaha presents a very unusual combination of characteristics making it a likely analog for some hydrocarbon-bearing lacustrine rocks of economic importance and possibly certain Precambrian environments, including expanding rift valleys and basins.

The field team performed on-site measurements of the water chemistry and microorganisms’ metabolic activity. They also sampled gases, waters at various depths, and procured a 1.8-meter-long sediment core for subsurface biodiversity, chemical, mineralogical, and isotopic analyses. DCO support is being provided to the highly leveraged research program to partially cover the cost of 14C analyses of the dissolved inorganic carbon and biomass, and of detrital remains of terrestrial plants found at various levels in the core. These analyses will test the hypothesis that the biomass feeds directly on volcanic CO2 and provide an approximate model age for the core. Information and a short video about the research program and field study is available on the DCO website: https://deepcarbon.net//feature/new-video-field-expedition-indian-ocean#.U-5QEVaF5mo

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Eastern Siberian Arctic Ocean Seafloor

Project Investigators: Weber, Tom ; Jerram, Kevin ; Mayer, Larry

Start Date: 2014-08-17

End Date: 2014-10-04

Summary: The seafloor of the Eastern Siberian Arctic Ocean holds significant, but as yet virtually unsurveyed, methane deposits.  As part of an international collaborative effort to better understand the climate, cryosphere and carbon system of the Arctic (SWERUS-C3),  we have been invited to use newly developed acoustic water-column imaging techniques to map the distribution (and to help quantify the flux) of methane gas seeps from the seafloor. Specifically, we hope to use the multibeam sonar onboard the Swedish Icebreaker ODEN to locate and characterize gas seeps in the water column and then apply a newly developed wideband transceiver to the split-beam echosounder onboard the ODEN to constrain the size and fate of gas bubbles rising to the surface. Together, these acoustic observations will help the SWERUS-C3 team understand the flux of methane from the seafloor into the water column and potentially into the atmosphere. If successful, these techniques will allow the mapping of the gas flux in the Arctic over scales never before possible. This proposal requests support for the participation of the UNH team on this expedition and for post-cruise work-up of the data. Among problems to be addressed by the SWERUS-C3 program are: (1) Quantification of methane release from subsea permafrost and the deep sea; (2) The fate of carbon in the shelf sea released from thawing coastal permafrost; (3) The magnitude of air/sea methane exchange; (4) The recent/post-glacial/paleoclimate sediment record of permafrost carbon releases, and; and (5) The longer-term history of Arctic sea ice and its impact on carbon fluxes. The UNH contribution will provide a means (using underway acoustic systems) to broadly map the location and character of gas seeping from the seafloor into the water column.

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Eruption Dynamics and Carbon Footprint of Hawaiian Hotspot Volcanoes - Hualalai Volcano, Hawaii

Project Investigators: Hauri, Erik; Trusdell, Frank ; Marske, Jared

Start Date: 2012-02-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2, H2O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions from the five active Hawaiian volcanoes (Loihi seamount, Kilauea, Mauna Loa, Mauna Kea and Hualalai) to determine the sources and fluxes of volatiles through the volcanic construction above the Hawaiian hotspot.

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Eruption Dynamics and Carbon Footprint of Hawaiian Hotspot Volcanoes - Koolau Volcano, Hawaii

Project Investigators: Hauri, Erik; Marske, Jared; Trusdell, Frank

Start Date: 2012-02-02

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions from the five active Hawaiian volcanoes (Loihi seamount, Kilauea, Mauna Loa, Mauna Kea and Hualalai) to determine the sources and fluxes of volatiles through the volcanic construction above the Hawaiian hotspot.

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Eruption Dynamics and Carbon Footprint of Hawaiian Hotspot Volcanoes - Loihi Seamount, Hawaii

Project Investigators: Trusdell, Frank ; Hauri, Erik; Marske, Jared

Start Date: 2012-02-01

End Date: 2020-01-01

Summary: This project uses measurements of CO2 , H2 O and other volatiles in deeply quenched submarine glasses and olivine-hosted melt inclusions from the five active Hawaiian volcanoes (Loihi seamount, Kilauea, Mauna Loa, Mauna Kea and Hualalai) to determine the sources and fluxes of volatiles through the volcanic construction above the Hawaiian hotspot.

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Furnas Volcano ECS Multidisciplinary Site

Project Investigators: Facq, Sébastien; Kietäväinen, Riikka; LaRowe, Doug; Price, Roy; Serovaiskii, Aleksandr; Yucel, Mustafa; Steen, Andrew; Zanon, Vittorio ; Miller, Quin; McDermott, Jill; Boulard, Eglantine; Andrade, César; Moreno, Lucía; Huang, Jinxiang; gonzalez, gino; Crespo-Medina, Melitza; Gagliano, Antonina Lisa; Schwarzenbach, Esther; Padilla-Crespo, Elizabeth; Nadeau, Olivier; Cox, Alysia; Thomas, Dana; Masotta, Matteo; Ma, Xiaogang; Kiseeva, Kate; Jesus, Ana Patricia; Hipólito, Ana Rita; Mikhail, Sami; Girault, Frederic; Azua-Bustos, Armando; Linhares, Diana; Pratt, Katie; Fischer, Rebecca; Silva, Catarina; Le Voyer, Marion; Hummer, Daniel; Gautam, Siddharth; Viveiros, Fatima; VISHAL, VIKRAM; Glenn, Ian; Baumberger, Tamara; Osburn, Magdalena; Pacheco, Joana; Barry, Peter

Start Date: 2015-08-31

End Date: 2015-09-05

Summary: At the beginning of September 2015, a group of 47 Early Career Scientists (ECS) met at the University of the Azores, Portugal, for a workshop sponsored by the Deep Carbon Observatory (DCO). The workshop was the third in a series of ECS events hosted by DCO, but this time the organizing committee tried something new.

We got permits to sample at Furnas hydrothermal field on São Miguel island, and knowing that we were bringing some very talented scientists to the workshop, we asked them to help plan and implement a day of sampling.

At the end of the workshop, we sent the recovered samples (fluids, sediments, and gases) home with 12 of the attendees. The goal is to generate both an open access publication and an openly available dataset.

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Global Circulation of Deep Earth Carbon

Project Investigators: Van Keken, Peter; Hauri, Erik

Start Date: 2013-04-01

Summary: The deep Earth carbon cycle lacks a basic global circulation model informed by geochemical research and experiments, which is necessary to describe the distribution of carbon with the vast depths of Earth inaccessible to sampling. This effort seeks to build the first deep Earth circulation model to simulate and test the distribution of carbon throughout Earth’s interior.

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Laser Isotope Ratio Meter for Real-Time in situ Measurements of Volcanic 13C/12C

Project Investigators: Jones, Adrian; Hussain, Ali ; Wylie, Robin; Brownsword, Richard

Start Date: 2011-04-01

Summary:

Measuring the carbon isotopic composition of volcanic gases is challenging. We are testing a new, ultra-portable laser system to measure carbon isotopic ratios at 1-second temporal resolution at a relative accuracy of ~1.8 per mil.

The laser system has achieved a relative accuracy of 1.8% on the δC13 value, for 1-second temporal resolution, which already places the instrument concept ahead of commercial solutions. The size of the instrument has been reduced by a factor of two, and made much more robust and simple to facilitate deployment in harsh environments. A novel optical scanning system has been implemented that provides superior signal stability and most of the interference signal from surrounding CO2 has been suppressed.

On the spectroscopy side, the collisional effect of increased CO2 concentration has been observed to contribute to the absorption line shape modification compared to air-broadening models only. This has been partially corrected.

A novel software-based demodulation process of the instrument signals has been tested and demonstrated to provide an order of magnitude improvement on the noise floor of the instrument.

 

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North Pole Dome, Australia

Project Investigators: Hazen, Robert M.

Start Date: 2014-06-17

End Date: 2014-06-27

Summary:

The North Pole Dome in Western Australia is a small feature within the ancient Pilbara Complex, which represents a remarkable raft of virtually unaltered crust from Earth’s Archean Eon. It is a roughly circular ring of hills, approximately 12 kilometers in diameter, surrounding a relatively flat depression that represents a “caldera”—the collapsed center of a 3.5 billion-year-old volcano. Following the collapse, the caldera gradually filled with layers of sediments, some of which contain pristine microbial fossil mounds called “stromatolites,” as well as other features that point to a dynamic shallow water environment.  

The  North Pole Dome holds Earth’s oldest unambiguous fossils, as well as extensive carbon-bearing rocks and hints regarding Earth’s early geochemical environment. This study will include detailed mapping of North Pole Dome hydrothermal systems and will investigate distributions of organic carbon, the geochemistry of carbonate minerals, and the nature and extent of diagnostic detrital minerals in these ancient rocks.

Geological Context: Life may have arisen in a hydrothermal environment, in an alkaline, low-temperature (<100°C) system. Indeed, the oldest convincing evidence for life occurs in just such a system, within the exceptionally well-preserved volcanic caldera and associated hydrothermal vein system of the ~3.5 Ga North Pole Dome, Pilbara Craton, Western Australia. Previous work documented a variety of early life signatures in this area, but it remains unclear whether early life was exclusively linked to hydrothermal systems, or if it occupied a variety of niches that reflect diverse microbial environments.

This field study will entail detailed mapping of carbon-bearing zones of the North Pole Dome hydrothermal system. We will also leverage ongoing detailed geological mapping and laboratory analysis of the North Pole Dome to explore three topics tied to DCO Decadal Goals related to Deep Life, Reservoirs and Fluxes, and Deep Energy. First, we will characterize the composition and distribution of carbonaceous materials within the North Pole hydrothermal system, to search for co-variation with changes in fluid temperature, system chemistry, and depth. These studies will assist with discriminating between a biogenic vs. abiogenic origin for the stromatolites, microfossils, and carbonaceous materials preserved in hydrothermal veins, in footwall basalts, in bedded sedimentary rocks, and perhaps in sulfide minerals. Second, we will characterize trace elements in carbonate minerals, including stromatolites. We will test hypotheses on redox-sensitive element distributions and will include these geochemical data as part of the DCO-sponsored Mineral Evolution Database project to develop an open access data infrastructure to probe Earth’s changing C cycle through deep time. Third, we will collect and analyze heavy detrital grains. The study of ancient detrital zircon (and to a lesser extent monazite) grains has opened a new window on early Earth. However, other potentially revealing ancient detrital heavy minerals, such as ilmenite, rutile, cassiterite, and uraninite, have not received comparable attention. We propose to acquire and analyze suites of these heavy mineral separates from the most ancient sedimentary terrains of Western Australia. These studies will complement and amplify decades of field and analytical research, representing millions of dollars in grants for investigations of North Pole Dome geology.

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Oman Drilling Project

Project Investigators: Nicolas, Adolphe; Sherwood Lollar, Barbara; Blackman, Donna; Shock, Everett; Pézard, Phillipe ; Al Rajhi, Ali; Langmuir, Charles H.; Klein, Frieder; Michibayashi, Katsuyoshi; Bani, Philipson ; Hirth, Greg; Miller, Jay; Coogan, Laurence; Matter, Jürg; MacLeod, Chris; Sonnenthal, Eric ; Jamveit, Bjorn; Manning, Craig; Umino, Susumu; Ceuleneer, Georges; Godard, Marguerite; Goldstein, Steven; Miyashita, Sumio ; Koepke, Jurgen; Nasir, Sobhi; Singh, Satish; Gouze, Philippe; Ildefonse, Benoit; Hofmann, Albrecht; Kelemen, Peter; Arai, Shoji; Teagle, Damon; Warren, Jessica; Takazawa, Eiichi

Start Date: 2014-04-01

End Date: 2017-03-31

Summary:

The Samail ophiolite in Oman and the United Arab Emirates (UAE) is the world’s largest, best-exposed, and most-studied subaerial block of oceanic crust and upper mantle. In an ongoing dialogue between geological studies of the ophiolite and seagoing investigations along modern oceanic ridges, observations from Oman and the UAE are central to scientific understanding of oceanic plates formed at spreading centers. Observations of mantle peridotites overlying the subduction zone thrust, which carried the ophiolite onto the Arabian continental margin, reveal an unexpected reservoir of carbon, derived from subducted sediments and precipitated as carbonate minerals in the mantle wedge. This could form an important, hitherto unrecognized part of the global carbon cycle. And, following on ground-breaking work in the 1980’s, there has been a recent surge of interest in the Samail ophiolite as the ideal site for studies of weathering in mantle peridotite, together with the subsurface biosphere fueled by microbial catalysis of low temperature alteration reactions. Such studies will contribute to understanding of microbial ecosystems in extreme environments and the origin of life.  

Following a successful workshop in September 2012, our international team of 38 investigators proposes a comprehensive drilling program in the Samail ophiolite in the Sultanate of Oman. Via observations on core, geophysical logging, fluid sampling, hydrological measurements, and microbiological sampling in a series of diamond- and rotary-drilled boreholes, we will address long-standing, unresolved questions regarding melt and solid transport in the mantle beneath oceanic spreading ridges, mass transfer between the oceans and the crust via hydrothermal alteration, and recycling of volatile components in subduction zones. We will undertake frontier exploration of subsurface weathering processes in mantle peridotite, natural mechanisms of carbon dioxide uptake from surface waters and the atmosphere via alteration and weathering, the process of reaction-driven cracking, and the nature of the subsurface biosphere in peridotite undergoing alteration and weathering. This aspect of the Oman Drilling Project is the one that is co-funded by the Sloan Foundation as part of the Integrative Field Studies for the Deep Carbon Observatory, Sloan Foundation Grant No: G-2014-3-01  Societally relevant aspects of our project include the involvement and training of university students in earth science research, including numerous students from Sultan Qaboos University in Oman. Studies of the natural system of mineral carbonation in peridotite will contribute to design of engineered systems for geological carbon dioxide capture and solid storage. More generally, our studies of alteration will contribute to fundamental understanding of the mechanisms of reaction-driven cracking: chemical reactions that cause subsurface cracking, enhancing permeability and reactive surface area, in a positive feedback mechanism. The results of these studies studies could enhance geothermal power generation and extraction of unconventional hydrocarbon resources.

 

Scientific drilling of the Semail Ophiolite in the Sultanate of Oman, commencing in late 2015 and continuing into 2017, represents a unique opportunity to understand the activities and distributions of a deep continental microbial biosphere associated with serpentinization. The project will drill up to 400 m into the ophiolite complex and is our best opportunity to-date to understand spatiotemporal relationships between serpentinization and subsurface life. The major goal of the Oman Drilling Project is to understand the conditions leading to low-temperature serpentinization and their consequences for carbon cycling, including their impact upon subsurface microbial communities. The DLC community will (1) work closely with hydrogeologists studying fluid flow and fluid chemistry in the Semail Ophiolite, (2) support activities aimed at instrumenting excavated wells to facilitate future observatory studies, and (3) conduct fluorescently activated cell sorting for downstream single cell genomics analyses. These efforts will all enable the study of microbial biogeography and dispersal in the serpentinitehosted subsurface environment.


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Quasi-Continuous CO2 Flux Measurement from Soil

Project Investigators: Norelli, Francesco ; Raco, Brunella ; Lelli, Matteo

Start Date: 2014-06-18

End Date: 2014-08-25

Summary: This project is aimed to perform quasi-continuous measurements of CO2 diffuse fluxes and of other needed parameters (i.e., soil temperature, humidity, and atmospheric pressure), developing a low-cost unit that is easy to install and manage. The availability of a quasi-continuous time series dataset helps the study and the estimation of CO2 fluxes from soil and in particular the identification of anomalies. The unit described in this project will make possible the creation of low-cost automatic monitoring networks.

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Recycling of Carbon During Subduction: Carbonate Eclogite Phase Relations from Upper Mantle to Transition Zone and Beyond

Project Investigators: Yaxley, Greg; Hirschmann, Marc; Rapp, Robert ; Vasilyev, Prokopiy ; Kiseeva, Kate; Enggist, Andreas

Start Date: 2011-04-01

Summary:

Carbon in oceanic crust and upper mantle is subducted at convergent margins, but the phase transformations that carbon undergoes, and hence its mobility, during subduction and transport to the deep upper mantle are not well known. We are undertaking high-pressure experiments (multi-anvil) on a range of carbonate and natural mid-ocean ridge basalt compositions to determine the phase relations and melting temperatures of carbon-bearing lithologies in subducting slabs.

DCO Fellow Enggist was hired in March of 2012. Subduction of altered, calcite-bearing oceanic crust is the primary return cycle of carbon from the exosphere to the deep mantle. Some subducted carbonate survives subduction through the sub-arc environment and is transported to the deeper upper mantle, transition zone or lower mantle. At low pressures (<10 GPa) carbonate-silicate exchange equilibria convert calcite to calcite-magnesite solid solution, which melts at a low T eutectic. Na+K carbonate components flux melting and lower solidus temperatures. At higher pressures alkali-bearing, Ca-Mg-Fe carbonates become stable and melting is controlled largely by the melting relations of these phases.

Experimental work has focused on determining the phase relations of carbonate compositions on the calcite-magnesite join at pressures ≥6 GPa. Several multi-anvil experiments have been conducted by Drs Enggist and Rapp at higher pressures (8 and 10 GPa) in this system, also aimed at determining minimum melting temperatures and compositions. Further experiments with alkali carbonate components added to the calcite-magnesite composition systematically address their effects on minimum melting relations and partial melt compositions in this pressure range. These simple-system experiments were used to inform further experiments in complex natural systems (modeling subducted carbonate-bearing MORB) in which stable carbonate compositions are complex and difficult to interpret as either melt or stable crystalline carbonate in the absence of comprehensive knowledge of phase relations in (Na,K)2CO3-CaCO3-MgCO3 simple systems.

Unexpectedly low solidus temperature (1000°C at 6 GPa, 1250°C at 15 GPa) may relate to fluxing by TiO2, Na2O, SiO2 and other contaminants. Comparison of this solidus with estimated P-T paths of subducting oceanic crust suggest that carbonate melts would form at relatively low pressures during subduction of hot crust. In the case of cooler crust, melting will not occur and carbonate may therefore be subducted into the deeper mantle.  We have also experimentally investigated the reaction carbonate + coesite = clinopyroxene + C + O2, which probably controls diamond versus carbonate stability in P-T-ƒO2-composition space in deeply subducted altered (i.e., carbonated) oceanic crust (eclogite). 

 

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Solubility of Carbonate Minerals and CO2 Speciation in Subduction Zone Fluids

Project Investigators: Azzolini, David ; Manning, Craig; Kavner, Abby ; Cardon, Herve; Li, Yuan ; Harrison, Brandon ; Montagnac, Gilles ; Newton, Robert ; Sverjensky, Dimitri; Duman, Louis ; Daniel, Isabelle; Facq, Sébastien; Eguchi, James

Start Date: 2011-04-01

Summary:

Carbon is subducted at convergent margins, but the capacity for fluids that are expelled from subducting slabs to carry carbon, and by extension the mobility of carbon during subduction, is not well known. We are undertaking high pressure experiments (DAC) on carbonate minerals, as well as numerical simulations to constrain the solubility of carbon (specifically calcite) in subduction zone fluids.

Experimental work at UCLA has focused on two aspects of calcium carbonate minerals at high pressure and temperature: their solubility in aqueous solutions, and trace element substitution into the carbonate mineral lattice. University of Lyon work has focused on in situ micro-Raman analysis of CaCO3 minerals (calcite, aragonite) dissolving in water in the diamond anvil cell at (P, T), 0.5 to 8 GPa and 250 to 500°C. The experimental results will be compared with the theoretical calculations in June 2012 during the visit of D. Sverjensky at the University of Lyon. Theoretical calculations of calcite solubility have been carried out for comparison with experimental data. The overall goal is be able to extend these calculations to pressures relevant to subduction zones.

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Spatio-temporal Modelling of Deep-time Atmospheric Carbon Flux from Subduction Zone Interactions with Carbonate Platforms

Project Investigators: Doss, Sebastiano; Pall, Jodie

Start Date: 2016-01-01

End Date: 2016-09-01

Summary:

This toolbox documents the workflows and contains the open-source python, pyGPlates and BASH codes that was produced over the course of the deep carbon modelling project. The purpose of the workflows presented here are to: (a) quantify the length of subduction zones; (b) analyse the interaction of carbonate platforms with subduction zones; (c) qualify subduction zone volcanism as being either intra-oceanic or continental arcs; and (d) quantify the carbon dioxide content of oceanic crust, all in a deep-time evolving plate tectonic framework. 

 

 

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Tectonic Fluxes of Carbon on Corsica

Project Investigators: Ague, Jay; Tian, Meng; Chu, Xu ; Vitale Brovarone, Alberto; Beyssac, Olivier; Rumble, Doug

Start Date: 2014-09-19

End Date: 2014-09-28

Summary: Because Alpine Corsica offers world-class exposures of high-pressure metamorphic rocks, it is a prime target for research as well as a workshop. Key questions about the fate of carbon in subduction zones may be investigated there, and processes such as carbonate devolatilization or dissolution and graphite formation or oxidation may be studied in situ. Moreover, redox phenomena involving serpentinite and methane production could have relevance for both the Deep Energy and Deep Life communities. Field work will commence in September 2014, and the project will continue over two years.

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Tectonic Fluxes of Deep Carbon

Project Investigators: Chu, Xu ; Tian, Meng; Marty, Bernard; Rumble, Doug; Beyssac, Olivier; Ague, Jay; Vitale Brovarone, Alberto

Start Date: 2013-04-01

Summary:

We seek to determine the flux of deep crustal and mantle carbon to the atmosphere from areas of active continental extension and mountain building. We will focus on (1) metamorphic processes, (2) erosional processes, (3) rifted areas and sedimentary basins, and (4) reduced carbon in tectonic areas.

(1) Tectonic Fluxes of Carbon Workshop

Just before the AGU fall meeting 2013, the DCO sponsored a workshop on ‘Tectonic Fluxes of Carbon’ held on Sunday December 8, 2013, at the San Francisco Mariott Marquis. The workshop was co-organized by Jay Ague (Yale, USA) and Olivier Beyssac (CNRS IMPMC Paris, France), and was attended by nearly 50 people representing eight 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 animated by a discussion leader, and included three keynotes by leading scientists in the domain. During lunch, a poster session allowed the participants to present their own research.

The workshop was focused on the ‘Tectonic Fluxes of Carbon’ covering potentially all non-volcanic carbon fluxes affecting the Earth’s lithosphere. The lithosphere has actually a key position in the carbon cycle at the interface between the exosphere (atmosphere, oceans, biosphere) and the deep Earth. Part of the discussion was dedicated to specific carbon fluxes during major geological processes like erosion or subduction, or 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 Appenines/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 modelling of carbon mobility at the Earth’s surface during erosion or in sedimentary basins. Altogether, it appears that the ‘Tectonic Fluxes of Carbon’ definitely require integrated multidisciplinary studies on different spatial and temporal scales of observation.

 

(2) Corsica field studies, co-principal investigators Ague and Beyssac

Because Alpine Corsica offers world-class exposures of high-pressure metamorphic rocks, it is a prime target for research as well as a workshop. Key questions about the fate of carbon in subduction zones may be investigated there, and processes like carbonate devolatilization or dissolution and graphite formation or oxidation may be studied in situ. Moreover, redox phenomena involving serpentinite and methane production could have relevance for both the Deep Energy and Deep Life communities. Field work will commence in September 2014, and the project will continue over two years.

 

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The Carbon Inventory of Oceanic Basalts and the Oceanic Upper Mantle

Project Investigators: Kelley, Katherine; Lytle, Marion ; Hauri, Erik; Le Voyer, Marion; Cottrell, Elizabeth

Start Date: 2011-04-01

Summary: The solubility of carbon in magmas is very low; most magmas have low carbon concentrations by the time they erupt to the surface. This has made it difficult to constrain the carbon content of the mantle where these magmas are sourced. We are studying the concentrations of carbon and other volatiles in a suite of well characterized mid-ocean ridge basaltic glass samples in order to assess (1) the carbon content of seafloor glass on a global scale and (2) the carbon content of mid-ocean ridge source mantle.

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Trail by Fire Expedition

Project Investigators: Peters, Nial

Start Date: 2015-11-08

End Date: 2016-03-31

Summary:

The atmosphere that allows our planet to sustain life was formed early in the Earth’s history, from gases emitted by volcanoes.

These gases, or volatile elements, are constantly recycled back into the deep earth at subduction zones, where tectonic plates sink into the mantle. During this process the sinking plate subjected to increasing heat and pressure releases volatiles which, added to the mantle, induce melting and fuel volcanic explosions, completing the cycle. While this depiction of the earth’s giant recycling factory is well established conceptually, we do not know how efficient it is. We can estimate how much goes in, but have little idea what proportion is released back to the atmosphere, and what proportion remains trapped at depth. This question is crucial if we want to understand how our atmosphere formed and our planet became able to sustain life. In the present-day context, characterizing how much gas comes out of the giant recycling factory is also key to understanding volcanic effects on climate, volcanic emissions being significant but poorly constrained parameters in current climate models.

The “Trail by Fire” project, funded by the 2015 bursary from Land Rover and the Royal Geographical Society (with the Institute of British Geographers) is an ambitious scientific expedition which will attempt to quantify the total amount of volatiles released by volcanoes along the Nazca subduction zone. Our objective is to provide the first accurate estimate of the flux of volatile species (H2O, CO2, SO2, H2, CO, HCl, HF, H2S and OCS) emitted by volcanoes along the entire length of the Nazca plate subduction zone (~6000 km). The journey will take us from the Southern tip of Chile all the way to the Equator. We will cross the cordillera through some of Earth’s highest roads and climb the tallest volcanoes in an attempt to understand the Earth’s giant recycling factory.

 Land Rover have turned a Defender 110 into the world’s first 4x4 volcano observatory, able to reach and measure active volcanoes never studied before. Just as an ambulance is effectively a mobile hospital, the Land Rover will be a mobile scientific laboratory. During the four month expedition from Peru to Southern Chile, the Land Rover will be our transportation, our living space, and our workshop. Through special modifications installed by Land Rover's Special Vehicle Operations, it will provide a power supply for our instruments and computers, and will even become a volcanic monitoring tool itself – fitted with spectrometers for traversing volcanic plumes. In effect, the Land Rover will be the seventh member of our team.

Source: http://trailbyfire.org

Updates on the Expedition: Deep Carbon Observatory Blog

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Volcanelium – Quantification of Regional Magma Degassing by High-Precision Isotope Analysis of Atmospheric Helium in Air Above Volcanic Areas

Project Investigators: Marty, Bernard; Burnard, Pete; Lan, Tefang; Mabry, Jennifer ; Fischer, Tobias

Start Date: 2011-04-01

Summary:

The helium isotopic composition of Earth’s interior is distinct from that of the exterior of Earth, and by measuring the helium isotopic composition of the atmosphere, CO2 gas fluxes out of volcanoes may be quantified. We are studying the helium isotopic composition of air, plumes, and fumeroles at Erte Ale and Mt. Etna volcanoes in order to test a dedicated mass spectrometer with sensitivity at the per mil level.

Field trip for sampling ambient air, volcanic plume, and fumaroles at Erta Ale, Ethiopia, took place in January 2011. Sampling at Kilauea, Hawaii (TF Lan) took place in March 2012. Two sampling campaigns were achieved at Mt Etna (Sicily) and surrounding in June 2012 and July 2013.

- Afar, Ethiopia. Helium measured in Afar appears systematically enriched in 3He by about 1-3 permil. This enrichment could represent mantle volatile degassing in this mantle plume - triple tectonic plate junction. Conversely, it could also represent a regional variation of the 3He/4He ratio in air worldwide since there has been a report that latitudinal variations exist. Hence we cannot conclude at this stage on the origin of these 3He excesses and we need further measurements. We have got a large (500cc) aliquot of air sampled at the Red Sea shore in Djibouti, presumably not influenced by degassing of the Afar hot spot, that we want to analyze at very high precision. At Erta Ale volcano, we have sampled several transects along the edifice as well as the volcanic plume from the active lava lake. Excesses of 3He are clearly seen and are integrated into a model to yield the flux of mantle-derived 3He and then that of CO2.

- Kilauea, Hawaii. Helium isotopic variations along the transect from Halemaumau crater to the coast fall in a range from -0.1 to +4.2 permil (compare to Nancy air). However the sample from South Point (~80 km from Halemaumau) shows similar excess 3He. This might indicate that the excess helium could be transported by wind within such a distance, or mantle degassing could be found not only at the crater area but also on the whole Big Island. As for Afar, we have a large sample of air taken at Oahu that will serve as a air reference for this latitude.

- Etna. During the two campaigns, air from the crater area, from the volcano flanks, and within the plume (sampled with an aircraft) has been collected and for most of samples, analyzed. excesses of 3He up to 4% have been recorded. An article that will integrate all data and quantify the 3He flux of Mt. Etna is in preparation.

In summary, we have sampled among the most volcanically active areas of the world. In all of these, we see excesses of 3He in the ambient air. We could detect such excesses down to the permil level using the analytical facility designed specifically for this type of measurement. Determining precisely the origin of these excesses require further measurements which are under way. Several papers, one per area, are under way, and we have already published a technical paper on the method.

 

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Volcanic Deep Earth Carbon Degassing (DECADE Organization)

Project Investigators: Galle, Bo; Hauri, Erik; Allard, Patrick; Fischer, Tobias; Aiuppa, Alessandro

Start Date: 2013-04-01

Summary:

In order to sharpen global estimates of carbon fluxes out of volcanoes, we will install CO2 monitoring networks on 25 of the world’s 150 most actively degassing volcanoes and undertake related studies (direct gas sampling and analysis, melt inclusions, satellite monitoring) to provide new data for direct degassing of deep Earth carbon to the hydrosphere.

Funding received in November 2013 was used to instrument 4 volcanoes in 2014 with permanent Multi-GAS devices, to monitor quantitatively volcanic CO2 fluxes by measuring the SO2 emission rates using ground-based DOAS combined with CO2/SO2 Multi-GAS measurements in the plumes. By March 2014, the installation of the first two MultiGASs at Turrialba (Costa Rica) and Masaya (Nicaragua) volcanoes was successfully completed Both instruments are working regularly with telemetry to local observatories (OVSICORI and INETER) and data transfer in Europe via ftp server.

The MaGa project is to create a web-based database for carbon degassing, MaGa: Mapping Gas emissions. The database has been upgraded from a previous version (Googas) and implemented with published datasets of volcanic and non-volcanic carbon-bearing gas manifestations in Italy, and nearby countries of the Mediterranean (Greece, Spain and Portugal). Upgrading of the database included implementation of the MaGa database structure, revision, update and ingestion of the existing Googas dataset into MaGa, and integration into the database of volcanic gas composition (and flux) datasets.

 

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