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Dirk De Beer - One of the best experts on this subject based on the ideXlab platform.

  • eruption of a deep sea Mud Volcano triggers rapid sediment movement
    Nature Communications, 2014
    Co-Authors: Tomas Feseker, Frank Wenzhöfer, Antje Boetius, Jerome Blandin, Karine Olu, Dana R Yoerger, Richard Camilli, Christopher R German, Dirk De Beer
    Abstract:

    Submarine Mud Volcanoes are important sources of methane to the water column. However, the temporal variability of their Mud and methane emissions is unknown. Methane emissions were previously proposed to result from a dynamic equilibrium between upward migration and consumption at the seabed by methane-consuming microbes. Here we show non-steady-state situations of vigorous Mud movement that are revealed through variations in fluid flow, seabed temperature and seafloor bathymetry. Time series data for pressure, temperature, pH and seafloor photography were collected over 431 days using a benthic observatory at the active Hakon Mosby Mud Volcano. We documented 25 pulses of hot subsurface fluids, accompanied by eruptions that changed the landscape of the Mud Volcano. Four major events triggered rapid sediment uplift of more than a metre in height, substantial lateral flow of Muds at average velocities of 0.4m per day, and significant emissions of methane and CO2 from the seafloor.

  • Methane and sulfide fluxes in permanent anoxia: in situ studies at the Dvurechenskii Mud Volcano (Sorokin Trough, Black Sea)
    Geochimica et Cosmochimica Acta, 2010
    Co-Authors: Anna Lichtschlag, Janine Felden, Frank Wenzhöfer, Florence Schubotz, Tobias F Ertefai, Antje Boetius, Dirk De Beer
    Abstract:

    The Dvurechenskii Mud Volcano (DMV) is located in permanently anoxic waters at 2060 m depth (Sorokin Trough, Black Sea). The DMV was studied during the RV Meteor expedition M72/2 as an example of an active Mud Volcano system, to investigate the significance of submarine Mud volcanism for the methane and sulfide budget of the anoxic Black Sea hydrosphere. Our studies included benthic fluxes of methane and sulfide, as well as the factors controlling transport, consumption and production of both compounds within the sediment. The pie-shaped Mud Volcano showed temperature anomalies as well as solute and gas fluxes indicating high fluid flow at its summit north of the geographical center. The anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) was repressed in this zone due to the upward flow of sulfate-depleted fluids through recently deposited subsurface Muds, apparently limiting microbial methanotrophic activity. Consequently, the emission of dissolved methane into the water column was high, with an estimated rate of 0.46 mol m−2 d−1. On the wide plateau and edge of the Mud Volcano surrounding the summit, fluid flow and total methane flux were lower, allowing higher SR and AOM rates correlated with an increase in sulfate penetration into the sediment. Here, between 50% and 70% of the methane flux (0.07–0.1 mol m−2 d−1) was consumed within the upper 10 cm of the sediment. The overall amount of dissolved methane released from the entire Mud Volcano structure into the water column was significant with a discharge of 1.3 × 107 mol yr−1. The DMV maintains also high areal rates of methane-fueled sulfide production and emission of on average 0.05 mol m−2 d−1. This is a difference to Mud Volcanoes in oxic waters, which emit similar amounts of methane, but not sulfide. However, based on a comparison of this and other Mud Volcanoes of the Black Sea, we conclude that sulfide and methane emission into the hydrosphere from deep-water Mud Volcanoes does not significantly contribute to the sulfide and methane inventory of the Black Sea.

  • Novel microbial communities of the Haakon Mosby Mud Volcano and their role as a methane sink.
    Nature, 2006
    Co-Authors: Helge Niemann, Tina Lösekann, Thierry Nadalig, Katrin Knittel, Eberhard J Sauter, Michael Schluter, Dirk De Beer, Rudolf Amann, Marcus Elvert, Michael Klages
    Abstract:

    Mud volcanism is an important natural source of the greenhouse gas methane to the hydrosphere and atmosphere. Recent investigations show that the number of active submarine Mud Volcanoes might be much higher than anticipated (for example, see refs 3-5), and that gas emitted from deep-sea seeps might reach the upper mixed ocean. Unfortunately, global methane emission from active submarine Mud Volcanoes cannot be quantified because their number and gas release are unknown. It is also unclear how efficiently methane-oxidizing microorganisms remove methane. Here we investigate the methane-emitting Haakon Mosby Mud Volcano (HMMV, Barents Sea, 72 degrees N, 14 degrees 44' E; 1,250 m water depth) to provide quantitative estimates of the in situ composition, distribution and activity of methanotrophs in relation to gas emission. The HMMV hosts three key communities: aerobic methanotrophic bacteria (Methylococcales), anaerobic methanotrophic archaea (ANME-2) thriving below siboglinid tubeworms, and a previously undescribed clade of archaea (ANME-3) associated with bacterial mats. We found that the upward flow of sulphate- and oxygen-free Mud Volcano fluids restricts the availability of these electron acceptors for methane oxidation, and hence the habitat range of methanotrophs. This mechanism limits the capacity of the microbial methane filter at active marine Mud Volcanoes to

  • novel microbial communities of the haakon mosby Mud Volcano and their role as a methane sink
    Nature, 2006
    Co-Authors: Tina Lösekann, Thierry Nadalig, Katrin Knittel, Helge Niemann, Dirk De Beer, Marcus Elvert, Rudolf Amann
    Abstract:

    Submarine Mud Volcanoes may be major players in the emission of the greenhouse gas methane. A select group of microorganisms, called methanotrophs, can consume this gas, but their impact on methane emission in this environment is not well understood. A study of the waters around a Mud Volcano in the Barents Sea has identified three key methanotrophic communities: aerobic bacteria, anaerobic archaea living beneath tubeworms, and previously undescribed archaea associated with bacterial mats. A natural cap on the capacity of the microbial methane filter was also discovered: the upward flow of sulphate- and oxygen-free volcanic fluids restricts the efficiency of methane oxidation, allowing much of the methane to escape to the hydrosphere and potentially the atmosphere. Mud volcanism is an important natural source of the greenhouse gas methane to the hydrosphere and atmosphere1,2. Recent investigations show that the number of active submarine Mud Volcanoes might be much higher than anticipated (for example, see refs 3–5), and that gas emitted from deep-sea seeps might reach the upper mixed ocean6,7,8. Unfortunately, global methane emission from active submarine Mud Volcanoes cannot be quantified because their number and gas release are unknown9. It is also unclear how efficiently methane-oxidizing microorganisms remove methane. Here we investigate the methane-emitting Haakon Mosby Mud Volcano (HMMV, Barents Sea, 72° N, 14° 44′ E; 1,250 m water depth) to provide quantitative estimates of the in situ composition, distribution and activity of methanotrophs in relation to gas emission. The HMMV hosts three key communities: aerobic methanotrophic bacteria (Methylococcales), anaerobic methanotrophic archaea (ANME-2) thriving below siboglinid tubeworms, and a previously undescribed clade of archaea (ANME-3) associated with bacterial mats. We found that the upward flow of sulphate- and oxygen-free Mud Volcano fluids restricts the availability of these electron acceptors for methane oxidation, and hence the habitat range of methanotrophs. This mechanism limits the capacity of the microbial methane filter at active marine Mud Volcanoes to <40% of the total flux.

  • novel microbial communities of the haakon mosby Mud Volcano and their role as a methane sink
    Nature, 2006
    Co-Authors: Tina Lösekann, Thierry Nadalig, Katrin Knittel, Helge Niemann, Dirk De Beer, Marcus Elvert, Rudolf Amann
    Abstract:

    Mud volcanism is an important natural source of the greenhouse gas methane to the hydrosphere and atmosphere. Recent investigations show that the number of active submarine Mud Volcanoes might be much higher than anticipated (for example, see refs 3-5), and that gas emitted from deep-sea seeps might reach the upper mixed ocean. Unfortunately, global methane emission from active submarine Mud Volcanoes cannot be quantified because their number and gas release are unknown. It is also unclear how efficiently methane-oxidizing microorganisms remove methane. Here we investigate the methane-emitting Haakon Mosby Mud Volcano (HMMV, Barents Sea, 72 degrees N, 14 degrees 44' E; 1,250 m water depth) to provide quantitative estimates of the in situ composition, distribution and activity of methanotrophs in relation to gas emission. The HMMV hosts three key communities: aerobic methanotrophic bacteria (Methylococcales), anaerobic methanotrophic archaea (ANME-2) thriving below siboglinid tubeworms, and a previously undescribed clade of archaea (ANME-3) associated with bacterial mats. We found that the upward flow of sulphate- and oxygen-free Mud Volcano fluids restricts the availability of these electron acceptors for methane oxidation, and hence the habitat range of methanotrophs. This mechanism limits the capacity of the microbial methane filter at active marine Mud Volcanoes to <40% of the total flux.

Anna Lichtschlag - One of the best experts on this subject based on the ideXlab platform.

  • intermediate sulfur oxidation state compounds in the euxinic surface sediments of the dvurechenskii Mud Volcano black sea
    Geochimica et Cosmochimica Acta, 2013
    Co-Authors: Anna Lichtschlag, Alexey Kamyshny, Timothy G Ferdelman, Dirk Debeer
    Abstract:

    Abstract The deep Black Sea is known to be depleted in electron-acceptors for sulfide oxidation. This study on depth distributions of sulfur species (S(II), S(0), S n 2 - , S 2 O 3 2 - , SO 3 2 - , SO 4 2 - ) in the Dvurechenskii Mud Volcano, a cold seep situated in the permanently anoxic eastern Black Sea basin (Sorokin Trough, 2060 m water depth), showed remarkable concentrations of sulfide oxidation products. Sulfite concentrations of up to 11 μmol L−1, thiosulfate concentrations of up to 22 μmol L−1, zero-valent sulfur concentrations of up to 150 μmol L−1 and up to five polysulfide species were measured in the upper 20 cm of the sediment. Electron-acceptors found to be available in the Dvurechenskii Mud Volcano (DMV) for the oxidation of hydrogen sulfide to sulfide oxidation intermediates are iron-minerals, and probably also reactive manganese phases. Up to 60 μmol g−1 of reactive iron-minerals and up to 170 μmol L−1 dissolved iron was present in the central summit with the highest fluid upflow and fresh Mud outflow. Thus, the source for the oxidative power in the DMV are reactive iron phases extruded with the Mud from an ancient source in the deeply buried sediments, leading to the formation of various sulfur intermediates in comparably high concentrations. Another possible source of sulfide oxidation intermediates in DMV sediments could be the formation of zero-valent sulfur by sulfate dependent anaerobic microbial oxidation of methane followed by disproportionation of zero-valent sulfur. Sulfide oxidation intermediates, which are produced by these processes, do not reach thermodynamic equilibrium with rhombic sulfur, especially close to the active center of the DMV due to a short equilibration time. Thus, Mud Volcano sediments, such as in the DMV, can provide oxidizing niches even in a highly reduced environment like the abyssal part of the Black Sea.

  • a novel mat forming thiomargarita population associated with a sulfidic fluid flow from a deep sea Mud Volcano
    Environmental Microbiology, 2011
    Co-Authors: Annechristi Girnth, Anna Lichtschlag, Stefanie Grunke, Janine Felde, Katri Knittel, Frank Wenzhofe, Dirk De Bee, Antje Oetius
    Abstract:

    A mat-forming population of the giant sulfur bacterium Thiomargarita was discovered at the flank of the Mud Volcano Amon on the Nile Deep Sea Fan in the Eastern Mediterranean Sea. All cells were of a spherical and vacuolated phenotype and internally stored globules of elemental sulfur. With a diameter of 24–65 µm, Thiomargarita cells from the Eastern Mediterranean were substantially smaller than cells of previously described populations. A 16S rRNA gene fragment was amplified and could be assigned to the Thiomargarita-resembling cells by fluorescence in situ hybridization. This sequence is monophyletic with published Thiomargarita sequences but sequence similarities are only about 94%, indicating a distinct diversification. In the investigated habitat, highly dynamic conditions favour Thiomargarita species over other sulfur-oxidizing bacteria. In contrast to Thiomargarita namibiensis populations, which rely on periodic resuspension from sulfidic sediment into the oxygenated water column, Thiomargarita cells at the Amon Mud Volcano seem to remain stationary at the sediment surface while environmental conditions change around them due to periodic brine flow.

  • Methane and sulfide fluxes in permanent anoxia: in situ studies at the Dvurechenskii Mud Volcano (Sorokin Trough, Black Sea)
    Geochimica et Cosmochimica Acta, 2010
    Co-Authors: Anna Lichtschlag, Janine Felden, Frank Wenzhöfer, Florence Schubotz, Tobias F Ertefai, Antje Boetius, Dirk De Beer
    Abstract:

    The Dvurechenskii Mud Volcano (DMV) is located in permanently anoxic waters at 2060 m depth (Sorokin Trough, Black Sea). The DMV was studied during the RV Meteor expedition M72/2 as an example of an active Mud Volcano system, to investigate the significance of submarine Mud volcanism for the methane and sulfide budget of the anoxic Black Sea hydrosphere. Our studies included benthic fluxes of methane and sulfide, as well as the factors controlling transport, consumption and production of both compounds within the sediment. The pie-shaped Mud Volcano showed temperature anomalies as well as solute and gas fluxes indicating high fluid flow at its summit north of the geographical center. The anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) was repressed in this zone due to the upward flow of sulfate-depleted fluids through recently deposited subsurface Muds, apparently limiting microbial methanotrophic activity. Consequently, the emission of dissolved methane into the water column was high, with an estimated rate of 0.46 mol m−2 d−1. On the wide plateau and edge of the Mud Volcano surrounding the summit, fluid flow and total methane flux were lower, allowing higher SR and AOM rates correlated with an increase in sulfate penetration into the sediment. Here, between 50% and 70% of the methane flux (0.07–0.1 mol m−2 d−1) was consumed within the upper 10 cm of the sediment. The overall amount of dissolved methane released from the entire Mud Volcano structure into the water column was significant with a discharge of 1.3 × 107 mol yr−1. The DMV maintains also high areal rates of methane-fueled sulfide production and emission of on average 0.05 mol m−2 d−1. This is a difference to Mud Volcanoes in oxic waters, which emit similar amounts of methane, but not sulfide. However, based on a comparison of this and other Mud Volcanoes of the Black Sea, we conclude that sulfide and methane emission into the hydrosphere from deep-water Mud Volcanoes does not significantly contribute to the sulfide and methane inventory of the Black Sea.

Thomas Pape - One of the best experts on this subject based on the ideXlab platform.

  • Mud extrusion and ring fault gas seepage upward branching fluid discharge at a deep sea Mud Volcano
    Scientific Reports, 2018
    Co-Authors: M. Loher, Heiko Sahling, Thomas Pape, Y. Marcon, M. Römer, P. Wintersteller, Daniel Praeg, Marta E Torres, Gerhard Bohrmann
    Abstract:

    Submarine Mud Volcanoes release sediments and gas-rich fluids at the seafloor via deeply-rooted plumbing systems that remain poorly understood. Here the functioning of Venere Mud Volcano, on the Calabrian accretionary prism in ~1,600 m water depth is investigated, based on multi-parameter hydroacoustic and visual seafloor data obtained using ship-borne methods, ROVs, and AUVs. Two seepage domains are recognized: Mud breccia extrusion from a summit, and hydrocarbon venting from peripheral sites, hosting chemosynthetic ecosystems and authigenic carbonates indicative of long-term seepage. Pore fluids in freshly extruded Mud breccia (up to 13 °C warmer than background sediments) contained methane concentrations exceeding saturation by 2.7 times and chloride concentrations up to five times lower than ambient seawater. Gas analyses indicate an underlying thermogenic hydrocarbon source with potential admixture of microbial methane during migration along ring faults to the peripheral sites. The gas and pore water analyses point to fluids sourced deep (>3 km) below Venere Mud Volcano. An upward-branching plumbing system is proposed to account for co-existing Mud breccia extrusion and gas seepage via multiple surface vents that influence the distribution of seafloor ecosystems. This model of Mud volcanism implies that methane-rich fluids may be released during prolonged phases of moderate activity.

  • vodyanitskii Mud Volcano sorokin trough black sea geological characterization and quantification of gas bubble streams
    Marine and Petroleum Geology, 2009
    Co-Authors: Heiko Sahling, Gerhard Bohrmann, Yuriy G Artemov, Andre Bahr, Markus Bruning, Stephan A Klapp, Ingo Klaucke, E V Kozlova, Aneta Nikolovska, Thomas Pape
    Abstract:

    Vodyanitskii Mud Volcano is located at a depth of about 2070 m in the Sorokin Trough, Black sea. It is a 500-m wide and 20-m high cone surrounded by a depression, which is typical of many Mud Volcanoes in the Black Sea. 75 kHz sidescan sonar show different generations of Mud flows that include Mud breccia, authigenic carbonates, and gas hydrates that were sampled by gravity coring. The fluids that flow through or erupt with the Mud are enriched in chloride (up to similar to 650 mmol L-1 at similar to 150-cm sediment depth) suggesting a deep source, which is similar to the fluids of the close-by Dvurechenskii Mud Volcano. Direct observation with the remotely operated vehicle QUEST revealed gas bubbles emanating at two distinct sites at the crest of the Mud Volcano, which confirms earlier observations of bubble-induced hydroacoustic anomalies in echosounder records. The sediments at the main bubble emission site show a thermal anomaly with temperatures at similar to 60 cm sediment depth that were 0.9 degrees C warmer than the bottom water. Chemical and isotopic analyses of the emanated gas revealed that it consisted primarily of methane (99.8%) and was of microbial origin (delta D-CH4 = -170.8 parts per thousand (SMOW), delta C-13-CH4 = -61.0 parts per thousand (V-PDB), delta C-13-C2H6 = -44.0 parts per thousand (V-PDB)). The gas flux was estimated using the video observations of the ROV. Assuming that the flux is constant with time, about 0.9 +/- 0.5 x 106 mol of methane is released every year. This value is of the same order-of-magnitude as reported fluxes of dissolved methane released with pore water at other Mud Volcanoes. This suggests that bubble emanation is a significant pathway transporting methane from the sediments into the water column. (C) 2009 Elsevier Ltd. All rights reserved.

Antje Boetius - One of the best experts on this subject based on the ideXlab platform.

  • eruption of a deep sea Mud Volcano triggers rapid sediment movement
    Nature Communications, 2014
    Co-Authors: Tomas Feseker, Frank Wenzhöfer, Antje Boetius, Jerome Blandin, Karine Olu, Dana R Yoerger, Richard Camilli, Christopher R German, Dirk De Beer
    Abstract:

    Submarine Mud Volcanoes are important sources of methane to the water column. However, the temporal variability of their Mud and methane emissions is unknown. Methane emissions were previously proposed to result from a dynamic equilibrium between upward migration and consumption at the seabed by methane-consuming microbes. Here we show non-steady-state situations of vigorous Mud movement that are revealed through variations in fluid flow, seabed temperature and seafloor bathymetry. Time series data for pressure, temperature, pH and seafloor photography were collected over 431 days using a benthic observatory at the active Hakon Mosby Mud Volcano. We documented 25 pulses of hot subsurface fluids, accompanied by eruptions that changed the landscape of the Mud Volcano. Four major events triggered rapid sediment uplift of more than a metre in height, substantial lateral flow of Muds at average velocities of 0.4m per day, and significant emissions of methane and CO2 from the seafloor.

  • Methane and sulfide fluxes in permanent anoxia: in situ studies at the Dvurechenskii Mud Volcano (Sorokin Trough, Black Sea)
    Geochimica et Cosmochimica Acta, 2010
    Co-Authors: Anna Lichtschlag, Janine Felden, Frank Wenzhöfer, Florence Schubotz, Tobias F Ertefai, Antje Boetius, Dirk De Beer
    Abstract:

    The Dvurechenskii Mud Volcano (DMV) is located in permanently anoxic waters at 2060 m depth (Sorokin Trough, Black Sea). The DMV was studied during the RV Meteor expedition M72/2 as an example of an active Mud Volcano system, to investigate the significance of submarine Mud volcanism for the methane and sulfide budget of the anoxic Black Sea hydrosphere. Our studies included benthic fluxes of methane and sulfide, as well as the factors controlling transport, consumption and production of both compounds within the sediment. The pie-shaped Mud Volcano showed temperature anomalies as well as solute and gas fluxes indicating high fluid flow at its summit north of the geographical center. The anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) was repressed in this zone due to the upward flow of sulfate-depleted fluids through recently deposited subsurface Muds, apparently limiting microbial methanotrophic activity. Consequently, the emission of dissolved methane into the water column was high, with an estimated rate of 0.46 mol m−2 d−1. On the wide plateau and edge of the Mud Volcano surrounding the summit, fluid flow and total methane flux were lower, allowing higher SR and AOM rates correlated with an increase in sulfate penetration into the sediment. Here, between 50% and 70% of the methane flux (0.07–0.1 mol m−2 d−1) was consumed within the upper 10 cm of the sediment. The overall amount of dissolved methane released from the entire Mud Volcano structure into the water column was significant with a discharge of 1.3 × 107 mol yr−1. The DMV maintains also high areal rates of methane-fueled sulfide production and emission of on average 0.05 mol m−2 d−1. This is a difference to Mud Volcanoes in oxic waters, which emit similar amounts of methane, but not sulfide. However, based on a comparison of this and other Mud Volcanoes of the Black Sea, we conclude that sulfide and methane emission into the hydrosphere from deep-water Mud Volcanoes does not significantly contribute to the sulfide and methane inventory of the Black Sea.

Adriano Mazzini - One of the best experts on this subject based on the ideXlab platform.

  • explosive Mud Volcano eruptions and rafting of Mud breccia blocks
    Earth and Planetary Science Letters, 2021
    Co-Authors: Michael Manga, G G Akhmanov, Adriano Mazzini, Alessandra Sciarra, Ayten Huseynova, Arif Huseynov, Ibrahim S. Guliyev
    Abstract:

    Abstract Azerbaijan hosts the highest density of subaerial Mud Volcanoes on Earth. The morphologies characterizing these structures vary depending on their geological setting, frequency of eruption, and transport processes during the eruptions. Lokbatan is possibly the most active Mud Volcano on Earth exhibiting impressive bursting events every ∼5 years. These manifest with impressive gas flares that may reach more than 100 meters in height and the bursting of thousands of m3 of Mud breccia resulting in spectacular Mud flows that extend for more than 1.5 kilometres. Unlike other active Mud Volcanoes, to our knowledge Lokbatan never featured any visual evidence of enduring diffuse degassing (e.g., active pools and gryphons) at and near the central crater. Only a very small new-born gryphon was intermittently active in 2019 (with negligible flow). Gas flux measurements completed with a closed-chamber technique reveal extremely low values throughout the structure with average CH 4 = 1.36 tonnes yr−1 and CO 2 = 11.85 tonnes yr−1. We suggest that after eruptive events, the Mud breccia is able to seal the structure preventing gas release and thereby promoting overpressure build-up in the subsurface. This self-sealing mechanism allows a fast recharge of Lokbatan resulting in more frequent and powerful explosive episodes. Our field observations reveal the presence of large (up to ∼50,000 m3) stratified blocks that were originally part of a large crater cone. These blocks were rafted >1 km from the vent on top of Mud breccia flows. We use a model based on lubrication theory to show that it is reasonable to transport blocks this large and this far provided the underlying Mud flow was thick enough and the blocks are large enough. The presence of large rafted blocks is not a unique phenomenon observed at Lokbatan Mud Volcano and is documented at other large-scale structures both onshore and offshore.

  • when Mud Volcanoes sleep insight from seep geochemistry at the dashgil Mud Volcano azerbaijan
    Marine and Petroleum Geology, 2009
    Co-Authors: Adriano Mazzini, G G Akhmanov, Henrik Svensen, Sverre Planke, Ibrahim S. Guliyev, T. Fallik, David Banks
    Abstract:

    The worlds >1500 Mud Volcanoes are normally in a dormant stage due to the short duration of eruptions. Their dormant stage activity is often characterized by vigorous seepage of water, gas, and petroleum. However, the source of the fluids and the fluid–rock interactions within the Mud Volcano conduit remain poorly understood. In order to investigate this type of activity, we have combined satellite images with fieldwork and extensive sampling of water and gas at seeping gryphons, pools and salsa lakes at the Dashgil Mud Volcano in Azerbaijan. We find that caldera collapse faults and E–W oriented faults determine the location of the seeps. The seeping gas is dominated by methane (94.9–99.6%), with a δ13C (‰ V-PDB) in the −43.9 to −40.4‰ range, consistent throughout the 12 analysed seeps. Ethane and carbon dioxide occur in minor amounts. Seventeen samples of seeping water show a wide range in solute content and isotopic composition. Pools and salsa lakes have the highest salinities (up to 101,043 ppm Cl) and the lowest δ18O (‰ V-SMOW) values (1–4‰). The Mud-rich gryphons have low salinities (<18,000 ppm Cl) and are enriched in 18O (δ18O = 4–6‰). The gas geochemistry suggests that the gases migrate to the surface from continuously leaking deep-seated reservoirs underneath the Mud Volcano, with minimal oxidation during migration. However, variations in gas wetness can be ascribed to molecular fractionation during the gas rise. In contrast, the water shows seasonal variations in isotopic composition and surface evaporation is proposed as a mechanism to explain high water salinities in salsa lakes. By contrast, gryphons have geochemical signals suggesting a deep-seated water source. These results demonstrate that the plumbing system of dormant Mud Volcanoes is continuously recharged from deeper sedimentary reservoirs and that a branched system of conduits exists in the shallow subsurface. While the gas composition is consistently similar throughout the crater, the large assortment of water present reflects the type of seep (i.e. gryphons versus pools and salsa lakes) and their location within the Volcano. Our data highlight the importance of a carefully planned sampling strategy when the target is water geochemistry, whereas the methane content and isotopic composition is relatively independent of the particular seep morphology.

  • When Mud Volcanoes sleep: insight from seep geochemistry at the Dashgil Mud Volcano, Azerbaijan
    Marine and Petroleum Geology, 2009
    Co-Authors: Adriano Mazzini, Henrik Svensen, Sverre Planke, Ibrahim S. Guliyev, Grigorii Akhmanov, T. Fallik, David Banks
    Abstract:

    The worlds >1500 Mud Volcanoes are normally in a dormant stage due to the short duration of eruptions. Their dormant stage activity is often characterized by vigorous seepage of water, gas, and petroleum. However, the source of the fluids and the fluid–rock interactions within the Mud Volcano conduit remain poorly understood. In order to investigate this type of activity, we have combined satellite images with fieldwork and extensive sampling of water and gas at seeping gryphons, pools and salsa lakes at the Dashgil Mud Volcano in Azerbaijan. We find that caldera collapse faults and E–W oriented faults determine the location of the seeps. The seeping gas is dominated by methane (94.9–99.6%), with a δ13C (‰ V-PDB) in the −43.9 to −40.4‰ range, consistent throughout the 12 analysed seeps. Ethane and carbon dioxide occur in minor amounts. Seventeen samples of seeping water show a wide range in solute content and isotopic composition. Pools and salsa lakes have the highest salinities (up to 101,043 ppm Cl) and the lowest δ18O (‰ V-SMOW) values (1–4‰). The Mud-rich gryphons have low salinities (

  • triggering and dynamic evolution of the lusi Mud Volcano indonesia
    Earth and Planetary Science Letters, 2007
    Co-Authors: Adriano Mazzini, G G Akhmanov, Henrik Svensen, Sverre Planke, Giovanni Aloisi, Anders Malthesorenssen, Bambang P. Istadi
    Abstract:

    Abstract Mud Volcanoes are geologically important manifestations of vertical fluid flow and Mud eruption in sedimentary basins worldwide. Their formation is predominantly ascribed to release of overpressure from clay- and organic-rich sediments, leading to impressive build-up of Mud mountains in submarine and subaerial settings. Here we report on a newly born Mud Volcano appearing close to an active magmatic complex in a backarc sedimentary basin in Indonesia. The location of the Mud Volcano close to magmatic Volcanoes results in a high background temperature gradient that triggers mineralogical transformations and geochemical reactions at shallow depth. The eruption of 100 °C Mud and gas that started the 29th of May 2006 flooded a large area within the Sidoarjo village in Northeast Java. Thousands of people have so far been evacuated due to the Mud flood hazards from the eruption. Since the initial eruption, the flow rate escalated from 5000 to 120,000 m 3 /d during the first eleven weeks. Then the erupted volume started to pulsate between almost zero and 120,000 m 3 /d in the period August 14 to September 10, whereas it increased dramatically following swarms of earthquakes in September, before reaching almost 180,000 m 3 /d in December 2006. Sampling and observations were completed during two fieldwork campaigns on the site. The eruption of boiling water is accompanied by Mud, aqueous vapour, CO 2 and CH 4 . Based on geochemical and field results, we propose a mechanism where the eruptions started following the 27th of May earthquake due to fracturing and accompanied depressurization of > 100 °C pore fluids from > 1700 m depth. This resulted in the formation of a quasi-hydrothermal system with a geyser-like surface expression and with an activity influenced by the regional seismicity.