Tectonic Controls on Gas Hydrate Distribution Off SW Taiwan
Autor: | Pascal Kunath, Malte Sommer, Ho-Han Hsu, Sebastian Hölz, Liwen Chen, Elodie Lebas, Char-Shine Liu, Gareth Crutchley, Ingo Klaucke, Andrew Lin, Christian Berndt, Kirk D McIntosh, Saulwood Lin, Sina Muff, Marion Jegen, Wu-Cheng Chi, Judith Elger, Tomas Feseker, Dirk Klaeschen |
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Rok vydání: | 2019 |
Předmět: |
010504 meteorology & atmospheric sciences
Subduction Clathrate hydrate 01 natural sciences Methane Tectonics Petroleum seep chemistry.chemical_compound Geophysics chemistry 13. Climate action Space and Planetary Science Geochemistry and Petrology Passive margin Earth and Planetary Sciences (miscellaneous) Thrust fault 14. Life underwater Hydrate Petrology Geology 0105 earth and related environmental sciences |
Zdroj: | Journal of Geophysical Research: Solid Earth, 124 (2). pp. 1164-1184. |
ISSN: | 2169-9356 2169-9313 |
Popis: | The northern part of the South China Sea is characterized by widespread occurrence of bottom simulating reflectors (BSR) indicating the presence of marine gas hydrate. Because the area covers both a tectonically inactive passive margin and the termination of a subduction zone, the influence of tectonism on the dynamics of gas hydrate systems can be studied in this region. Geophysical data show that there are multiple thrust faults on the active margin while much fewer and smaller faults exist in the passive margin. This tectonic difference matches with a difference in the geophysical characteristics of the gas hydrate systems. High hydrate saturation derived from ocean bottom seismometer data and controlled source electromagnetic data and conspicuous high‐amplitude reflections in P‐Cable 3D seismic data above the BSR are found in the anticlinal ridges of the active margin. In contrast all geophysical evidence for the passive margin points to normal to low hydrate saturations. Geochemical analyses of gas samples collected at seep sites on the active margin show methane with heavy δ13C isotope composition, while gas collected at the passive margin shows light carbon isotope composition. Thus, we interpret the passive margin as a typical gas hydrate province fuelled by biogenic production of methane and the active margin gas hydrate system as a system that is fuelled not only by biogenic gas production but also by additional advection of thermogenic methane from the subduction system. |
Databáze: | OpenAIRE |
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