Open AccessMethane Venting in Gas Hydrate Potential Area Offshore of SW Taiwan: Evidence of Gas Analysis of Water Column Samples
Author(s) -
Tsanyao Frank Yang,
Pei-Chuan Chuang,
Saulwood Lin,
Ju-Chin Chen,
Yun-Shuen Wang,
ShyhJong Chung
Publication year - 2006
Publication title -
terrestrial, atmospheric and oceanic sciences/terrestrial, atmospheric, and oceanic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.35
H-Index - 46
eISSN - 2223-8964
pISSN - 1017-0839
DOI - 10.3319/tao.2006.17.4.933(gh
Subject(s) - clathrate hydrate , methane , submarine pipeline , methane gas , petroleum engineering , gas analysis , column (typography) , water column , environmental science , geology , offshore oil and gas , natural gas , hydrate , oceanography , waste management , environmental chemistry , chemistry , engineering , organic chemistry , structural engineering , connection (principal bundle)
Water column samples were collected systematically in several potential gas hydrate areas offshore of SW Taiwan for analysis of dissolved gases. Some these samples show unusually high dissolved methane concentrations at sites A, B, C, and H of cruise ORI-765. The profiles of helium concentrations in the dissolved gases of the water column also exhibit consistent results with an increasing trend toward the seafloor. The 3He/4He ratios range from 0.2 to 0.4 times that of the atmospheric air ratio after air correction, which fall in the range of typical crustal gas composition and are similar to those of on-shore mud volcanoes in SW Taiwan. This indicates that gases are venting actively from the seafloor in the region and may share similar gas sources to on-shore mud volcanoes. The venting gases are considered to have originated from dissociation of gas hydrates and/or a deeper gas reservoir