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Methane entrapped in calcareous proglacial soils: abundance, origin, and fate

Applicant Schroth Martin H.
Number 153571
Funding scheme Project funding (Div. I-III)
Research institution Institut für Biogeochemie und Schadstoffdynamik ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Other disciplines of Environmental Sciences
Start/End 01.01.2015 - 31.12.2018
Approved amount 268'297.00
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Keywords (5)

Entrapped methane; Greenhouse gas; Methane oxidation; Proglacial zone; Methane inventory

Lay Summary (German)

Lead
Das starke Treibhausgas Methan liefert einen wichtigen Beitrag zur globalen Erwärmung, und wird deshalb im Rahmen von nationalen und internationalen Strategien zur Verminderung von Treibhausgasemissionen explizit berücksichtigt. Eingeschlossen in Kalksedimenten in Schweizer Gletschervorfeldern haben wir vor Kurzem erhöhte Konzentrationen an Methan entdeckt. In diesem Projekt werden wir die Menge und Verteilung des eingeschlossenen Methans, sowie sein Alter, seine Herkunft und sein mögliches Abbauverhalten studieren.
Lay summary

In terrestrischen Systemen wie Böden und Sedimenten wird der Methanumsatz überwiegend durch Mikroorganismen katalysiert. Dabei sind Studien zu Methanumsätzen in Böden, die sich in einem frühen Entwicklungsstadium befinden (junge Böden), immer noch selten. In der Schweiz findet man junge Böden in Gletschervorfeldern, wo aufgrund des anhaltenden Gletscherschwundes kontinuierlich Sedimente der Bodenbildung preisgegeben werden. Eingeschlossen in Kalksedimenten von Gletschervorfeldern in der Schweiz hat unsere Forschungsgruppe kürzlich das starke Treibhausgas Methan entdeckt. Allerdings ist die Menge und Verteilung des eingeschlossenen Methans, sowie sein Alter, seine Herkunft und sein mögliches Abbauverhalten bisher unbekannt. Da das eingeschlossene Methan durch mechanische Einwirkung bzw. durch Ansäuerung freigesetzt werden kann, besteht die Möglichkeit, dass es in die Atmosphäre gelangen könnte.

Ziel dieses Projektes ist es, die wesentlichen Eigenschaften dieser neu entdeckten Methanquelle zu erforschen. Speziell möchten wir ein Inventar des eingeschlossenen Methans (Menge und Verteilung) für ausgewählte Gletschervorfelder in der Schweiz erstellen. Darüber hinaus werden wir das Alter und die Herkunft des eingeschlossenen Methans bestimmen. Schliesslich werden wir das Freisetzungs- und Abbauverhalten des Methans studieren, z.B. während Niederschlagsereignissen.

Diese Forschungsarbeit wird detaillierte Einsicht in die Bedeutung der neu entdeckten Methanquelle in den Schweizer Alpen geben. Darüber hinaus wird die Arbeit einen wichtigen neuen Beitrag zu bestehenden Studien zu Methanumsätzen in glazialen Systemen liefern. Ausserdem werden die wissenschaftlichen Resultate dieser Arbeit wertvolle Informationen zur Relevanz von Gletschervorfeldern für zukünftige Methanemissionsinventare generieren.

Direct link to Lay Summary Last update: 19.09.2014

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Quantity and distribution of methane entrapped in sediments of calcareous, Alpine glacier forefields
ZhuBiqing, KüblerManuel, RidoliMelanie, BreitensteinDaniel, SchrothMartin H. (2020), Quantity and distribution of methane entrapped in sediments of calcareous, Alpine glacier forefields, in Biogeosciences Discussions, bg-2019-49.
Inventory on entrapped methane in the Griessfirn proglacial soil (M.Sc. thesis)
Kübler Manuel (2019), Inventory on entrapped methane in the Griessfirn proglacial soil (M.Sc. thesis), ETH Research Collection, Zürich.
Occurrence and Origin of Methane Entrapped in Sediments and Rocks of a Calcareous, Alpine Glacial Catchment
Zhu Biqing, Henneberger Ruth, Weissert Helmut, Zeyer Josef, Schroth Martin H. (2018), Occurrence and Origin of Methane Entrapped in Sediments and Rocks of a Calcareous, Alpine Glacial Catchment, in Journal of Geophysical Research: Biogeosciences, 123(12), 3633-3648.
Inventory of Methane (CH4) in soils of selected calcareous glacier forefields in the Swiss Alps (M.Sc. thesis)
Ridoli Melanie, Inventory of Methane (CH4) in soils of selected calcareous glacier forefields in the Swiss Alps (M.Sc. thesis), ETH Research Collection, Zurich.

Collaboration

Group / person Country
Types of collaboration
Department Surface Waters - Research and Management/EAWAG Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Stable Isotope and Organic Geochemical Laboratory / ETH Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Fall Meeting of the American Geophysical union Poster Inventory of Methane Entrapped in Sediments of Calcareous, Alpine Glacier Forefields in Switzerland 10.12.2018 Washington, DC, United States of America Schroth Martin H.; Zhu Biqing;
Fall Meeting of the American Geophysical Union Poster Fate of Methane Entrapped in Calcareous Alpine Proglacial Soils Under Variable Environmental Conditions 10.12.2018 Washington, DC, United States of America Schroth Martin H.; Zhu Biqing;
European Geosciences Union General Assembly Poster Origin and Distribution of Methane Entrapped in Calcareous Alpine Proglacial Soils 23.04.2017 Vienna, Austria Schroth Martin H.; Zhu Biqing;
Fall Meeting of the American Geophysical Union Poster Origin of Methane Entrapped in Calcareous Alpine Proglacial Sediments 12.12.2016 San Francisco, CA, United States of America Zhu Biqing; Schroth Martin H.;


Associated projects

Number Title Start Funding scheme
137721 Methane Turnover in Alpine Glacier Forefields 01.01.2012 Project funding (Div. I-III)

Abstract

Methane (CH4) is an important contributor to global warming, and is therefore considered within international and national policy frameworks for mitigation of greenhouse-gas emissions. However, confirmation on the success of mitigation efforts requires accurate inventories on emissions and uptake of individual greenhouse gases. In terrestrial systems, CH4 turnover is largely mediated by microorganisms (methanogens and methanotrophs). While CH4 turnover is extensively studied in fully developed soils, data on CH4 sources and sinks in soils at early development stages are still scarce. In Switzerland, such young soils can be found in increasingly large proglacial zones in front of receding glaciers. So far, these soils have not been considered in CH4 emission inventories.Methane was recently discovered to be entrapped in Swiss proglacial soils, in particular in those derived from calcareous bedrock. This CH4 can be released upon mechanical impact or acidification. However, the amount and distribution of entrapped CH4, its age and origin (biogenic or thermogenic), as well as its potential fate in the proglacial environment remain unknown. Therefore, the overall goal of this project is to elucidate these aspects for CH4 entrapped in calcareous proglacial soils. The project will provide detailed insights into the significance of this recently discovered CH4 source in the Swiss Alps. Results of this research will reveal new aspects for CH4 inventory and turnover in soils at early development stages. The specific objectives are to:I.Provide a detailed inventory (abundance and distribution) of CH4 entrapped in soils of selected calcareous proglacial zones in the Swiss AlpsII. Determine the age and origin of CH4 entrapped in soils of selected calcareous proglacial zonesIII.Determine the fate of CH4 entrapped in soils of one individual calcareous proglacial zoneIn the first phase, we will investigate soils in selected calcareous proglacial zones in the Swiss Alps to answer questions regarding commonality of CH4 entrapment between, and total amount and spatial distribution of entrapped CH4 within proglacial zones. To efficiently sample a large number of locations and depths, we will mostly rely on field measurements (one-time soil-gas sampling) of CH4 released by hammering a sampling device into the soils. Based on these measurements and a calibration procedure, we will produce an estimate on the total amount of CH4 entrapped for different soil-age groups and landforms within proglacial zones. Additional samples will be collected and analyzed for CH4 content from locations that will serve as reference, e.g., from bedrock outcrops to obtain a baseline value for the amount of CH4 stored in the parent bedrock. In the second phase, we will collect soil samples from selected locations within proglacial zones to assess the age and origin of entrapped CH4. This will be accomplished using multiple lines of evidence including 14C radiocarbon dating to discriminate between modern and fossil CH4, stable isotope analyses of CH4 (d13C and d2H) and gas wetness (concentration ratio of CH4/SC2-C5 alkanes) as indicators for the origin of CH4, and molecular analyses to assess the presence, abundance, diversity, and activity of methanogens.In the third phase, we will investigate the natural release of entrapped CH4 from calcareous proglacial soils by diffusive transport (“seeping”) and as a result of precipitation events that provide acidity with rainwater. In parallel, we will assess the potential of the indigenous community of methanotrophs to oxidize released CH4, thereby attenuating emissions to the atmosphere. These objectives will be addressed in a series of laboratory column experiments with soils from one selected proglacial zone. To corroborate findings obtained in the laboratory, we will conduct few selected field-scale experiments in the corresponding proglacial zone.
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