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  • 1
    Type of Medium: Electronic Resource
    Pages: 1 CD-ROM , 1 Booklet (XX, 40, 24 S.)
    Edition: [Elektronische Ressource]
    Series Statement: Proceedings of the ocean drilling program 204.2002
    Language: English
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  • 2
    Keywords: Oceanography ; Water ; Hydrology ; Cogeneration of electric power and heat ; Fossil fuels ; Physical geography ; Business ; Management science ; Gashydrate ; Simulation ; Sediment ; Kontinentalrand ; Methanhydrate
    Type of Medium: Book
    Pages: XXI, 514, C3 Seiten , Illustrationen, Karten
    Edition: Corrected Publication 2022
    ISBN: 3030811859 , 9783030811853
    DDC: 551.46
    Language: English
    Note: Literaturangaben
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  • 3
    In: Geochemistry, geophysics, geosystems, Hoboken, NJ : Wiley, 2000, 10(2009), 11, 1525-2027
    In: volume:10
    In: year:2009
    In: number:11
    In: extent:21
    Description / Table of Contents: We report on a bathymetric mapping and remotely operated vehicle surveys along the 100600 m region offshore Oregon from 43ʿ50?N to 44°18'N. We interpret our results in light of available geophysical data, published geotectonic models, and analogous observations of fluid venting and carbonate deposition from 44°30'N to 45°00'N. The methane seepage is defined by juxtaposition of a young prism, where methane is generated by bacterial activity and its release is modulated by gas hydrate dynamics, against older sequences that serve as a source of thermogenic hydrocarbons that vent in the shelf. We hypothesize that collision of a buried ridge with the Siletz Terrane results in uplift of gas hydrate bearing sediments in the oncoming plate and that the resulting decrease in pressure leads to gas hydrate dissociation and methane exolution, which, in turn, may facilitate slope failure. Oxidation of the released methane results in precipitation of carbonates that are imaged as high backscatter along a 550 ± 60 m benthic corridor.
    Type of Medium: Online Resource
    Pages: 21 , Ill., graph. Darst
    ISSN: 1525-2027
    Language: English
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  • 4
    Online Resource
    Online Resource
    Cham : Springer International Publishing | Cham : Imprint: Springer
    Keywords: Oceanography. ; Water. ; Fossil fuels. ; Physical geography. ; Business. ; Management science. ; Erde ; Kontinentalrand ; Gashydrate ; Offshore-Vorkommen ; Geologie ; Seismik ; Schelf ; Methanlagerstätte ; Erdgasgeologie ; Gashydrate ; Seismische Prospektion ; Vorkommen
    Description / Table of Contents: Part I. A History of gas hydrate research -- Chapter 1. Gas Hydrate Research: From the Laboratory to the Pipeline -- Chapter 2. Shallow gas hydrates near 64° N, off Mid-Norway: Concerns regarding drilling and production technologies -- Chapter 3. Finding and using the world’s gas hydrates -- Part II. Gas Hydrate Fundamentals -- Chapter 4. Seismic rock physics of gas-hydrate bearing sediments -- Chapter 5. Estimation of gas hydrates in the pore space of sediments using inversion methods -- Chapter 6. Electromagnetic applications in methane hydrate reservoirs -- Part III. Gas Hydrate Drilling for Research and Natural Resources -- Chapter 7. Hydrate Ridge - A gas hydrate system in a subduction zone setting -- Chapter 8. Northern Cascadia Margin gas hydrates – Regional geophysical surveying, IODP drilling Leg 311 and cabled observatory monitoring -- Chapter 9. Accretionary wedge tectonics and gas hydrate distribution in the Cascadia forearc -- Chapter 10. Bottom Simulating Reflections below the Blake Ridge, western North Atlantic Margin -- Chapter 11. A review of the exploration, discovery, and characterization of highly concentrated gas hydrate accumulations in coarse-grained reservoir systems along the Eastern Continental Margin of India -- Chapter 12. Ulleung Basin Gas Hydrate Drilling Expeditions, Korea: Lithologic characteristics of gas hydrate-bearing sediments -- Chapter 13. Bottom simulating reflections in the South China Sea -- Chapter 14. Gas hydrate and fluid related seismic indicators across the passive and active margins off SW Taiwan -- Chapter 15. Gas Hydrate Drilling in the Nankai Trough, Japan -- Chapter 16. Alaska North Slope Terrestrial Gas Hydrate Systems: Insights from Scientific Drilling -- Part IV -- Arctic -- Chapter 17. Gas Hydrates on Alaskan Marine Margins -- Chapter 18. Gas Hydrate related bottom-simulating reflections along the west-Svalbard margin, Fram Strait -- Chapter 19. Occurrence and distribution of bottom simulating reflections in the Barents Sea -- Chapter 20. Svyatogor Ridge - A gas hydrate system driven by crustal scale processes -- Chapter 21. Gas hydrate potential in the Kara Sea -- Part V. Greenland and Norwegian Sea -- Chapter 22. Geophysical indications of gas hydrate occurrence on the Greenland continental margins -- Chapter 23. Gas hydrates in the Norwegian Sea -- Part VI. North Atlantic. Chapter 24. U.S. Atlantic Margin Gas Hydrates -- Chapter 25. Gas Hydrates and submarine sediment mass failure: A case study from Sackville Spur, offshore Newfoundland -- Chapter 26. Bottom Simulating Reflections and Seismic Phase Reversals in the Gulf of Mexico -- Chapter 27. Insights into gas hydrate dynamics from 3D seismic data, offshore Mauritania -- Part VII. South Atlantic -- Chapter 28. Distribution and Character of Bottom Simulating Reflections in the Western Caribbean Offshore Guajira Peninsula, Colombia -- Chapter 29. Gas hydrate systems on the Brazilian continental margin -- Chapter 30. Gas hydrate on the southwest African continental margin -- Chapter 31. Shallow gas hydrates associated to pockmarks in the Northern Congo deep-sea fan, SW Africa -- Part VIII. Pacific -- Chapter 32. Gas hydrate-bearing province off eastern Sakhalin slope -- Chapter 33. Tectonic BSR Hypothesis in the Peruvian margin: A forgotten way to see marine gas hydrate systems at convergent margins -- Chapter 34. Gas hydrate and free gas along the Chilean Continental Margin -- Chapter 35. New Zealand’s Gas Hydrate Systems -- Part IX. Indic -- Chapter 36. First evidence of bottom simulation reflectors in the western Indian Ocean offshore Tanzania -- Part X. Mediterranean Sea -- Chapter 37. A Gas Hydrate System of Heterogenous Character in the Nile Deep-Sea Fan -- Part XI. Black Sea -- Chapter 38. Gas hydrate accumulations in the Black Sea -- Part XII. Lake Baikal -- Chapter 39. The position of gas hydrates in the sedimentary strata and in the geological structure of Lake Baikal -- Part XIII. Antarctic -- Chapter 40. Bottom Simulating Reflector in the western Ross Sea Antarctica -- Chapter 41. Bottom Simulating Reflectors along the Scan Basin, a deep-sea gateway between the Weddell Sea (Antarctica) and Scotia Sea -- Chapter 42. Bottom Simulating Reflections in Antarctica -- Part XIV. Where Gas Hydrate Dissociates Seafloor Microhabitats Flourish. Chapter 43. Integrating fine-scale habitat mapping and pore water analysis in cold seep research: A case study from the SW Barents Sea.
    Type of Medium: Online Resource
    Pages: 1 Online-Ressource(XXI, 515 p. 311 illus., 296 illus. in color.)
    Edition: 1st ed. 2022.
    ISBN: 9783030811860
    Series Statement: Springer eBook Collection
    Language: English
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  • 5
    Online Resource
    Online Resource
    Cham :Springer International Publishing AG,
    Keywords: Natural gas-Hydrates. ; Electronic books.
    Type of Medium: Online Resource
    Pages: 1 online resource (501 pages)
    Edition: 1st ed.
    ISBN: 9783030811860
    DDC: 553.285
    Language: English
    Note: Intro -- Preface -- Contents -- Editors and Contributors -- A History of Gas Hydrate Research -- 1 Gas Hydrate Research: From the Laboratory to the Pipeline -- Abstract -- 1.1 General Aspects -- 1.2 Experimental Hydrate Research -- 1.2.1 Multiscale Approach -- 1.2.2 Overview of Experimental Techniques -- 1.2.2.1 Small (Laboratory) Scale -- 1.2.2.2 Pilot Scale -- 1.3 Final Considerations -- Acknowledgements -- References -- 2 Shallow Gas Hydrates Near 64° N, Off Mid-Norway: Concerns Regarding Drilling and Production Technologies -- Abstract -- 2.1 Introduction -- 2.2 The Nyegga Gas Hydrate Location -- 2.2.1 General -- 2.2.2 The BSR -- 2.2.2.1 BSR-Related Drilling and Engineering Concerns -- 2.2.3 Complex Pockmarks -- 2.2.4 Hydrate Pingoes -- 2.2.4.1 A Qualitative Model for Hydrate Pingo Formation -- 2.2.5 Carbonate Rubble -- 2.2.6 Pockmark-, Carbonate Rubble-, and Pingo-Related Engineering Concerns -- 2.2.7 Unique Fauna -- 2.2.8 Fauna-Related Drilling and Engineering Concerns -- 2.2.9 Gas Chimneys -- 2.2.10 Gas-Chimney Related Drilling, Production, and Engineering Concerns -- 2.3 Husmus Geological Setting -- 2.3.1 General -- 2.3.2 The Shallow BSR at Husmus -- 2.3.3 Husmus-Related Drilling and Engineering Concerns -- 2.4 Ormen Lange Gas Seeping Event -- 2.4.1 Gas Seepage-Related Drilling and Engineering Concerns -- 2.5 Conclusions -- Acknowledgements -- References -- 3 Finding and Using the World's Gas Hydrates -- Abstract -- 3.1 Introduction-The Location of Gas Hydrates Beneath the Seabed -- 3.2 History of Gas Hydrate Exploration and Global Assessments of Distribution -- 3.3 The Importance of Natural Gas Hydrates -- 3.3.1 The Role of Gas Hydrates in Climate Change -- 3.3.2 Hydrates as a Control on Benthic Ecosystems -- 3.3.3 The Role of Gas Hydrates in Slope Stability -- 3.3.4 Hydrates as a Future Energy Source. , 3.3.5 Carbon Capture and Storage (CCS) in Gas Hydrate Reservoirs -- 3.4 Evidence of Submarine Gas Hydrates -- 3.4.1 Geophysical Evidence -- 3.4.2 Quantifying Hydrates Through Chemical Measurements of Cores -- 3.4.3 Borehole Logging -- 3.5 Gas Hydrates in the Solar System: Applying Lessons from Earth -- 3.6 Summary -- References -- Gas Hydrate Fundamentals -- 4 Seismic Rock Physics of Gas-Hydrate Bearing Sediments -- Abstract -- 4.1 Introduction -- 4.2 Dry-Rock Moduli -- 4.2.1 Elastic Moduli from Theoretical Models -- 4.2.2 Dry-Rock Elastic Moduli from Calibration -- 4.3 Effective-Fluid Model for Partial Saturation -- 4.4 Permeability -- 4.5 Attenuation -- 4.6 Seismic Velocities -- 4.7 Estimation of the Seismic Velocities and Attenuation -- 4.8 Conclusions -- References -- 5 Estimation of Gas Hydrates in the Pore Space of Sediments Using Inversion Methods -- Abstract -- 5.1 Introduction -- 5.2 Methods, Physical Properties and Microstructures Used for Hydrate Quantification -- 5.3 Strategy for Gas Hydrate Exploration and Quantification -- 5.4 Conclusions -- References -- 6 Electromagnetic Applications in Methane Hydrate Reservoirs -- Abstract -- 6.1 Introduction -- 6.2 Electrical Properties of Gas Hydrates -- 6.2.1 Saturation Estimates -- 6.3 Marine CSEM Principle -- 6.4 CSEM Data Interpretation -- 6.5 CSEM Instrumentation and Exploration History -- 6.5.1 Seafloor-Towed Systems -- 6.5.2 Deep-Towed Systems -- 6.5.3 Other Systems -- 6.6 Global Case Studies -- 6.7 Discussion and Conclusions -- References -- Gas Hydrate Drilling for Research and Natural Resources -- 7 Hydrate Ridge-A Gas Hydrate System in a Subduction Zone Setting -- Abstract -- 7.1 Introduction -- 7.2 Tectonic Setting -- 7.3 Stratigraphy and Structure -- 7.4 The Bottom Simulating Reflection Across Hydrate Ridge -- 7.5 Hydrate Occurrence and Distribution Within Hydrate Ridge. , 7.5.1 Hydrate Concentrations from Drilling -- 7.5.2 Inferred Hydrates and Free Gas Regionally Across Hydrate Ridge -- 7.6 Conclusions -- References -- 8 Northern Cascadia Margin Gas Hydrates-Regional Geophysical Surveying, IODP Drilling Leg 311 and Cabled Observatory Monitoring -- Abstract -- 8.1 Introduction -- 8.2 Regional Occurrences of Gas Hydrate Inferred from Remote Sensing Data -- 8.3 The Gas Hydrate Petroleum System for the Northern Cascadia Margin -- 8.4 Gas Hydrate Saturation Estimates -- 8.5 Gas Vents, Focused Fluid Flow and Shallow Gas Hydrates -- 8.6 Long-Term Observations -- 8.6.1 Gas Emissions at the Seafloor -- 8.6.2 Controlled-Source EM and Seafloor Compliance -- 8.6.3 Borehole In Situ Monitoring -- 8.7 Summary and Conclusions -- Acknowledgements -- References -- 9 Accretionary Wedge Tectonics and Gas Hydrate Distribution in the Cascadia Forearc -- Abstract -- 9.1 Introduction -- 9.2 Data -- 9.3 Results -- 9.4 Summary -- Acknowledgements -- References -- 10 Bottom Simulating Reflections Below the Blake Ridge, Western North Atlantic Margin -- Abstract -- 10.1 Geologic Setting -- 10.2 A Brief History of Blake Ridge Gas Hydrate Research -- 10.3 Blake Ridge BSR Distribution, Character and Dynamics -- 10.3.1 A Dynamic BSR on the Eastern Flank of Blake Ridge -- 10.3.2 Gas Chimneys Extending from BSRs -- 10.3.3 The Role of Sediment Waves in Gas Migration from the BSR -- 10.3.4 The Blake Ridge Diapir -- 10.4 Unanswered Questions and Future Research -- References -- 11 A Review of the Exploration, Discovery and Characterization of Highly Concentrated Gas Hydrate Accumulations in Coarse-Grained Reservoir Systems Along the Eastern Continental Margin of India -- Abstract -- 11.1 Introduction -- 11.2 India National Gas Hydrate Program-Scientific Drilling Expeditions -- 11.3 Representative Gas Hydrate Systems-Krishna-Godavari Basin. , 11.3.1 Krishna-Godavari Basin Geologic Setting -- 11.3.2 NGHP-02 Area C Gas Hydrate System -- 11.3.3 NGHP-02 Area B Gas Hydrate System -- 11.4 Summary -- Acknowledgements -- References -- 12 Ulleung Basin Gas Hydrate Drilling Expeditions, Korea: Lithologic Characteristics of Gas Hydrate-Bearing Sediments -- Abstract -- 12.1 Introduction -- 12.2 Geological Setting of the Ulleung Basin -- 12.3 Overview of the First and Second Ulleung Basin Gas Hydrate Drilling Expeditions (UBGH1 and 2) -- 12.4 Lithologic Characteristics of Gas Hydrate-Bearing Sediments in the Ulleung Basin -- 12.5 Summary -- References -- 13 Bottom Simulating Reflections in the South China Sea -- Abstract -- 13.1 Introduction -- 13.2 Geological Setting and Gas Hydrate Drilling Expeditions -- 13.3 The Characteristics of BSRs Within Various Sediment Environments -- 13.3.1 BSR and Cold Seeps in Taixinan Basin -- 13.3.2 BSRs in the Pearl River Mouth Basin -- 13.3.3 BSRs in the Qiongdongnan Basin -- 13.4 Well Log Anomalies of Different Types of Gas Hydrate -- 13.5 BSR Dynamics and Response to Fluid Migration -- 13.6 Summary -- Acknowledgements -- References -- 14 Gas Hydrate and Fluid-Related Seismic Indicators Across the Passive and Active Margins off SW Taiwan -- Abstract -- 14.1 Introduction -- 14.2 Geological Setting -- 14.3 Seismic Observations -- 14.3.1 Gas Accumulation -- 14.3.2 Fluid Migration -- 14.3.3 Presence of Gas Hydrate -- 14.4 Distribution of the Seismic Indicators and Implications for Understanding the Hydrate System -- 14.5 Summary -- References -- 15 Gas Hydrate Drilling in the Nankai Trough, Japan -- Abstract -- 15.1 Introduction -- 15.2 Discovery of Gas Hydrates and Early Expeditions in the Nankai Trough Area -- 15.3 MITI Exploratory Test Well: Nankai Trough (1999-2000) -- 15.4 METI Multi-well Exploratory Drilling Campaign and Resource Assessments. , 15.4.1 Drilling Operations and Achievements -- 15.4.2 Discovery of the Methane Hydrate Concentration Zone and Resource Assessments -- 15.5 Tests for Gas Production Undertaken in 2013 and 2017 -- 15.5.1 Gas Production Techniques and Site Selection -- 15.5.2 Drilled Boreholes and Data/Sample Acquisitions -- 15.5.3 Production Test Results and Findings -- 15.6 Other Gas Hydrate Occurrences and Resource Evaluation Results -- 15.7 Summary -- Acknowledgements -- References -- 16 Alaska North Slope Terrestrial Gas Hydrate Systems: Insights from Scientific Drilling -- Abstract -- 16.1 Introduction -- 16.2 Alaska North Slope Gas Hydrate Accumulations -- 16.3 Alaska North Slope Gas Hydrate Research Drilling Programs -- 16.3.1 Mount Elbert Gas Hydrate Stratigraphic Test Well -- 16.3.2 Iġnik Sikumi Gas Hydrate Production Test Well -- 16.3.3 Hydrate-01 Stratigraphic Test Well -- 16.4 Alaska North Slope Gas Hydrate Energy Assessments -- 16.5 Summary -- Acknowledgements -- References -- Arctic -- 17 Gas Hydrates on Alaskan Marine Margins -- Abstract -- 17.1 Introduction -- 17.2 Southeastern Alaskan Margin -- 17.3 Aleutian Arc -- 17.3.1 Eastern Aleutian Arc -- 17.3.2 Central Aleutian Arc -- 17.3.3 Western Aleutian Arc -- 17.3.4 Bering Sea -- 17.4 US Beaufort Sea -- 17.5 Summary -- Acknowledgements -- References -- 18 Gas Hydrate Related Bottom-Simulating Reflections Along the West-Svalbard Margin, Fram Strait -- Abstract -- 18.1 Introduction -- 18.2 Geological and Oceanographic Settings -- 18.2.1 Regional Tectonic Setting -- 18.2.2 Sedimentary Setting -- 18.2.3 Oceanographic Setting -- 18.3 BSR Distribution and Characteristics Within Various Sediment Types -- 18.3.1 Regional Extent of the BSRs -- 18.4 Evidence for Gas Migration from Deep and Shallow Sources -- 18.4.1 The Gas Sources -- 18.4.2 Vertical Fluid Migration Features -- 18.5 Inferred Gas Hydrate Distribution. , 18.6 BSR Dynamics and Response to Natural Changes in the Environment.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Marine geophysical researches 5 (1981), S. 69-78 
    ISSN: 1573-0581
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A model representing the coupling of an ocean-bottom seismometer (OBS) to the seafloor as a mass-spring-dashpot system satisfactorily explains the results of transient tests performed on different instruments during the Lopez Island intercomparison test. In this paper, we compare the results obtained for the MIT OBS at Lopez Island to results from similar tests at a dockside site at Woods Hole, Massachusetts. The vertical instrument response at the Lopez Island site shows a highly damped resonance at a frequency of 22 Hz, whereas the response at the Woods Hole site shows a marked resonance at 13 Hz. The difference between the responses at the two sites can be qualitatively attributed to the difference between the surficial sediments.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Marine geophysical researches 16 (1994), S. 91-103 
    ISSN: 1573-0581
    Keywords: Ocean-bottom seismographs ; coupling seismographs to sea floor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A series of transient tests were conducted to determine the seafloor coupling characteristics of a new ocean-bottom seismometer (OBS) developed for the United States Office of Naval Research (ONR). The OBS comprises a large recording package and a separate sensor package that is deployed from the recording package. In addition to the coupling characteristics of both the sensor and the recording packages, the seismic energy radiated from the main recording package as a result of motion of the recording package was measured. The observed vertical coupling resonances of both the recording package and the sensor package are in good agreement with those predicted by a simple model of soil-structure interaction. The most important result of this study is that significant energy is radiated from the recording package in response to horizontal motions of the recording package. When the sensor package is 1 m from the recording package, the amplitude of the recorded signal is similar to that recorded in the recording package. In the field, this effect will result in distortion of seismic signals and increased background noise recorded by the sensor package if the recording package is disturbed by seafloor currents or biological activity. The amplitude of this signal attenuates by approximately a factor of two as sensor/recorder separation is increased from 1 to 6 m, suggesting that an improved response can be achieved by increasing the separation between the recording package and the sensors. This effect is much less severe for vertical disturbances of the recording package.
    Type of Medium: Electronic Resource
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  • 8
    Publication Date: 2021-02-08
    Description: Key Points: Multibeam bathymetric and seismic reflection data image the structure of the North Chilean marine forearc and the oceanic Nazca plate The structural character and tectonic configuration of the offshore forearc and the oceanic plate change significantly along the margin The derived pattern of permanent deformation may hold information for studying seismicity or other types of short term deformation New multibeam bathymetry allows an unprecedented view of the tectonic regime and its along‐strike heterogeneity of the North Chilean marine forearc and the oceanic Nazca Plate between 19‐22.75°S. Combining bathymetric and backscatter information from the multibeam data with sub‐bottom profiler and published and previously unpublished legacy seismic reflection lines, we derive a tectonic map. The new map reveals a middle and upper‐slope configuration dominated by pervasive extensional faulting, with some faults outlining a 〉500 km long ridge that may represent the remnants of a Jurassic or pre‐Jurassic magmatic arc. Lower slope deformation is more variable and includes slope‐failures, normal faulting, re‐entrant embayments, and NW‐SE trending anticlines and synclines. This complex pattern likely results from the combination of subducting lower‐plate topography, gravitational forearc collapse, and the accumulation of permanent deformation over multiple earthquake cycles. We find little evidence for widespread fluid seepage despite a highly faulted upper‐plate. An explanation could be a lack of fluid sources due to the sediment starved nature of the trench and most of the upper‐plate in vicinity of the hyper‐arid Atacama Desert. Changes in forearc architecture partly correlate to structural variations of the oceanic Nazca Plate, which is dominated by the spreading‐related abyssal hill fabric and is regionally overprinted by the Iquique Ridge. The ridge collides with the forearc around 20‐21°S. South of the ridge‐forearc intersection, bending‐related horst‐and‐grabens result in vertical seafloor offsets of hundreds of meters. To the north, plate‐bending is accommodated by reactivation of the paleo‐spreading fabric and new horst‐and‐grabens do not develop.
    Type: Article , PeerReviewed
    Format: text
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  • 9
    Publication Date: 2016-01-06
    Description: Log and core data document gas saturations as high as 90% in a coarse-grained turbidite sequence beneath the gas hydrate stability zone (GHSZ) at south Hydrate Ridge, in the Cascadia accretionary complex. The geometry of this gas-saturated bed is defined by a strong, negative-polarity reflection in 3D seismic data. Because of the gas buoyancy, gas pressure equals or exceeds the overburden stress immediately beneath the GHSZ at the summit. We conclude that gas is focused into the coarse-grained sequence from a large volume of the accretionary complex and is trapped until high gas pressure forces the gas to migrate through the GHSZ to seafloor vents. This focused flow provides methane to the GHSZ in excess of its proportion in gas hydrate, thus providing a mechanism to explain the observed coexistence of massive gas hydrate, saline pore water and free gas near the summit.
    Type: Article , PeerReviewed
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  • 10
    Publication Date: 2021-04-28
    Description: The 2014 Mw 8.1 Iquique earthquake ruptured the boundary between the subducting Nazca Plate and the overriding South American Plate in the North Chilean subduction zone. The broken segment of the South American subduction zone had likely accumulated elastic strain since an M~9 earthquake in 1877 and what therefore considered a mature seismic gap. The moderate magnitude of the 2014 earthquake and its compact rupture area, which only broke the central part of the seismic gap, did not result in a significant tsunami in the Pacific Ocean. To investigate the seismo-tectonic segmentation of the North Chilean subduction zone in the region of the 2014 Iquique earthquake at the shallow seismic/aseismic transition, we combine two years of local aftershock seismicity observations from ocean bottom seismometers and long-offset seismic reflection data from the rupture area. Our study links short term deformation associated with a single seismic cycle to the permanent deformation history of an erosive convergent margin over millions of years. A high density of aftershocks following the 2014 Iquique earthquake occurred in the up-dip region of the coseismic rupture, where they form a trench parallel band. The events spread from the subducting oceanic plate across the plate boundary and into the overriding continental crust. The band of aftershock seismicity separates a pervasively fractured and likely fluid-filled marine forearc farther seaward from a less deformed section of the forearc farther landward. At the transition, active subduction erosion during the postseismic and possibly coseismic phases of the 2014 Iquique earthquake leads to basal abrasion of the upper plate and associated extensional faulting of the overlying marine forearc. Landward migration of the seismogenic up-dip limit, possibly at similar rates compared to the trench and the volcanic arc, leaves behind a heavily fractured and fluid-filled outermost forearc. This most seaward part of the subduction zone might be too weak to store sufficient elastic strain to nucleate a large megathrust earthquake.
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: text
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