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| Titel |
Geochemical Anomalies of Pore Water of Cored Sediments in Offshore Southwestern Taiwan |
| VerfasserIn |
Hsuan-Wen Chen, Tsanyao Frank Yang, Saulwood Lin, San-Hsiung Chung, Yunshuen Wang |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250038478
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| Zusammenfassung |
| According to the previous geochemical studies, the venting gases mainly consist of methane.
As we know, the gas hydrate may be formed when gases migrate upward through the gas
hydrate stability zone. Besides, the previous geophysical data shows that BSRs (Bottom
Simulating Reflection) distribute widely in this area. These evidences imply that there would
be a methane hydrate reservoir in Offshore Southwestern Taiwan. Since some of the general
surveys have been done in this area, we focus on one of the ridges - the Good Weather Ridge
for detail studies.
As other ridges in this area, abundant methane concentrations had been found in
the pore space of cored sediments. The analytical result shows that the methane
concentration at some sites can reach 9*10^3 μL/L. Meanwhile, the shallow depth of
SMI infers the high methane flux underneath the seafloor. These high methane
fluxes may represent a great amount of methane hydrates existing in the marine
sediments.
In addition to the methane concentrations, the chloride ion in the pore water
can be another indicator for hydrate surveys. On Good Weather Ridge, the clear
chloride concentration decreases with depth has been observed from Core 9 and other
sites, and it is lower than the average value of seawater in this area. However, the
pore space methane concentration is up to around 7*10^3 μL/L at the same cored
sediments. It indicates that in-situ gas hydrates may have dissociated during core
recovering. Therefore, the amount of gas hydrates in the cores can be estimated. |
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