Coseimic massive methane release from a submarine mud volcano
详细信息 查看全文
- 作者：Urumu Tsunogai ; Kenji Maegawa ; Shintaro Sato ; Dasiuke D. Komatsu ; Fumiko Nakagawa ; Tomohiro Toki ; Juichiro Ashi
- 关键词：mud volcano ; earthquake ; methane plume ; eruption ; stable carbon isotopes
- 刊名：Earth and Planetary Science Letters
- 出版年：2012
- 出版时间：August, 2012
- 年：2012
- 卷：341-344
- 期：Complete
- 页码：79-85
- 全文大小：798 K
文摘
We report here the discovery of two methane-enriched plumes in a water column above the Kumano Knoll ?5 submarine mud volcano (KK#5) in Nankai Trough during 2004; a slight methane enrichment was observed in this region in 2000 and 2010. The deeper of the two plumes spread horizontally at depths near the top of KK#5, whereas a shallow plume spread at a height of 300 m from the top of KK#5. The end-member ¦Ä13C values of methane in both plumes, ?46.1¡À4.8¡ë and ?51.4¡À5.8¡ë in the deep and shallow plumes, respectively, and methane extracted from sediment in KK#5 (?52¡À2¡ë) are statistically indistinguishable. We conclude that the plumes were created by massive release of methane from KK#5 and that this event probably occurred in response to the large earthquakes (Mw 7.5) that occurred shortly before our observation in 2004. The discharge rates from submarine mud volcanoes (SMVs) in subduction zones may be highly variable in response to major earthquakes.