Kolvetni í jarðhitagasi - verkefni lokið
Fréttatilkynning verkefnisstjóra
Rannsóknarverkefnið Kolvetni í jarðhitagasi leitaðist við að skilgreina uppruna og efnahvörf kolvetnis á jörðinni. Sýnum af jarðhitagasi var safnað víðs vegar um heim (á Íslandi, Nýja Sjálandi, Kenía og víðar) og styrkur og samsætuhlutföll kolvetna efnagreind.
Niðurstöðurnar sýna að uppruna kolvetna í jarðhitagasi má fyrst og fremst rekja til niðurbrots á lífrænu efni frekar en ólífrænna efnahvarfa eins og áður hefur verið talið. Alþjóðlegur hópur vísindamanna vann að rannsókninni og hafa niðurstöður hennar verið birtar í ritrýndum vísindatímaritum.
English:
Short project summary: The project Hydrocarbons in volcanic hydrothermal fluids aimed at assessing the sources and reactions of hydrocarbons on Earth. Hydrothermal fluid samples were collected around the world (Iceland, New Zealand, Kenya and elsewhere) and analyzed for carbon and hydrocarbon gas abundances and isotopes. With this first global dataset, we suggest that hydrocarbons in hydrothermal fluids primarily originate from open system degradation of organic matter where abiotic hydrocarbon occurrences may have been significantly overestimated in the past. The project was carried out by a multi-national research team and the results have been published in scientific journals.
The results of the work have been introduced at several international conferences and published in per-reviewed scientific journals or are in preparation or under consideration for publication (see list below).
Publications on hydrocarbons:
· Fiebig J., Stefánsson, A., Ricci, A., Tassi, F., Viveiros, F., Silva, C., Lopez, T.M., Schreiber, C., Hofmann, S., Mountain, B.W. (2019) Abiogenesis not required to explain the origin of volcanic-hydrothermal hydrocarbons. Geochem. Perspect. Let. 2019 II, 23-27 (open access)
· Beaudry P., Rhim J.H., Stefansson A., Fiebig J., Ono S. (2019) High-temperature generation of methane in terrestrial geothermal systems: evidence from clumped isotopologues. DeepCarbon 2019 [abstract and poster] (open access)
· Beaudry P., Rhim J.H., Stefansson A., Fiebig J., Ono S. (2019) Generation of methane in hydrothermal fluids constrained from clumped isotopologues. Geochimica Cosmochimca Acta [in preparation]
· Ricci A., Stefánsson A., Fiebig J. (2020) Hydrocarbon abundances, isotopes in hydrothermal fluids, Iceland. Geochimica. Cosmochimca Acta [in preparation]
· Fiebig J, Tassi F, Stefansson A, Viveiros F, Silva C, D'Alessandro W, Ricci A, Schreiber C, Lopez T & Mountain B (2018) Abiotic Hydrocarbons in Earth's Crust: A Phantom? Goldshcmidt 2018 [abstract and oral presentation] (open access)
· Beaudry P, Rhim J, Stefánsson A, Fiebig J & Ono S (2018) Methane Clumped Isotopologue Thermometry of Icelandic Geothermal Gases. Goldshcmidt 2018 [abstract and poster] (open access)
· Fiebig J, Tassi F, Stefansson A, Viveiros F, D'Alessandro W, Ricci A & Lopez T (2017) Isotopic Constraints on the Origin of Hydrocarbons in Volcanic-Hydrothermal Emissions. Goldschmidt 2017 [abstract and oral presentation] (open access)
Publications using data collected as a part of this project:
· Labidi J, PH Barry, DV Bekaert, MW Broadley, B Marty, T Giunta, O Warr, B Sherwood Lollar, TP Fischer, G Avice, A Caracausi, CJ Ballentine, SA Halldórsson, A Stefánsson, MD Kurz, IE Kohl, ED Young (2020) Hydrothermal 15N15N abundances constrain the origins of mantle nitrogen. Nature 580 (7803), 367-371 [the samples collected as a part of this project were used in this paper] (open access)
· A Stefansson, A Sveinbjörnsdóttir, J Heinemeier (2019) Origin of the CO2 fluxes of the Icelandic Hotspot. AGUFM 2019, V51I-0170 [abstract] (open access)
· Stefánsson A., (2017) Gas chemistry of Icelandic thermal fluids. J. Volcanol. Geotherm. Res. 346, 81-94.
· Byrne DJ, Barry PH, Halldórsson SA, Broadley MW, Stefánsson A & Ballentine CJ (2019) Tracing Geothermal Fluid Interactions in Iceland Using Noble Gases. Goldschmidt 2019 [abstract and poster] (open access)
· Ricci A., Stefánsson A., Fiebig J. (2020) Kinetics and thermodynamics of hydrogen isotope fractionation between H2 and H2O in natural hydrothermal fluids. Geochimica. Cosmochimca Acta [in preparation]
· Byrne D.J., Barry P. H., Halldórsson S. A., Broadley M. W., Stefánsson A., Ballentine C. J. (2020) Tracing mantle and groundwater fluid interactions in Icelandic geothermal systems using noble gas isotope analysis. Chem. Geol. [in preparation]
· Kamunya MK (2018) δD and δ18O systematics in geothermal fluids, Olkaria Geothermal. MSc thesis University of Iceland, 56 pp. (open access)
Heiti verkefnis: Kolvetni í jarðhitagasi/Hydrocarbons
in volcanic hydrothermal fluids
Verkefnisstjóri: Andri Stefánsson, Háskóla Íslands
Tegund styrks: Verkefnisstyrkur
Styrktímabil: 2015-2017
Fjárhæð styrks: 26,656 millj. kr. alls
Tilvísunarnúmer Rannís: 152680
