Coseimic massive methane release from a submarine mud volcano
Coseimic massive methane release from a submarine mud volcano
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DOI：
10.1016/j.epsl.2012.06.004
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发表时间：
2012-08
影响因子：
5.3
通讯作者：
U. Tsunogai;K. Maegawa;Shin Sato;D. D. Komatsu-D.;F. Nakagawa;T. Toki;J. Ashi
中科院分区：
文献类型：
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作者：
U. Tsunogai;K. Maegawa;Shin Sato;D. D. Komatsu-D.;F. Nakagawa;T. Toki;J. Ashi
本文报道了2004年在南海海槽熊野丘5号海底泥火山（KK#5）上方水柱中发现的两个富甲烷羽流; 2000年和2010年在该区域观察到轻微的甲烷富集。两个羽流中较深的一个在KK#5顶部附近的深度水平扩散，而一个较浅的羽流在距离KK#5顶部300米的高度扩散。两个地幔柱中甲烷的端元δ 13 C值，深、浅地幔柱分别为−46.1±4.8‰和−51.4±5.8‰，而KK#5沉积物中甲烷的端元δ 13 C值（−52±2‰）在统计学上无法区分。我们的结论是，羽状物是由KK#5的大量甲烷释放产生的，这一事件可能是对2004年我们观测前不久发生的大地震（Mw7.5）的反应。俯冲带海底泥火山（SMVs）的喷发速率可能会因大地震而发生很大变化。
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 300m from the top of KK#5. The end-member δ13C values of methane in both plumes, −46.1±4.8‰ and −51.4±5.8‰ in the deep and shallow plumes, respectively, and methane extracted from sediment in KK#5 (−52±2‰) 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 (Mw7.5) 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.