Correlations Between Direct Current Resistivity And Seismic Attribute Tests Across An Active Methane Hydrate Vent In Mississippi Canyon Block 118, Gulf Of Mexico

Subsurface methane sources and migration pathways within a gas hydrate mound system, Gulf of Mexico

“…Large outcrops of methane hydrates at the seabed have been observed at MC118 over a period of at least 11 years [ Lapham et al ., ; Macelloni et al ., ; Sassen et al ., ]. The presence of buried hydrate at this site has been inferred from resistivity data [ Gunnell and Dunbar , ] and confirmed by coring during geologic surveys [ Macelloni et al ., ]. This recovered hydrate had low methane/ethane (C 1 /C 2 ) ratios and methane isotope values up to −47‰ implying that the source gas was thermogenic [ Sassen et al ., ].…”

“…The surface expression of the blue fault is associated with an expulsion crater (the northwest crater, near “JPC1” in Figure ) [ Macelloni et al ., ], extensive bacterial mats [ Lutken et al ., ], and high rates of microbial activity [ Lapham et al ., ]. Extensive seismic surveys of this fault have revealed a nearby resistivity anomaly [ Gunnell and Dunbar , ] and high‐frequency scatter in the shallow‐source deep‐receiver (SSDR) data [ Simonetti et al ., ]. Based on these seismic indicators, the blue fault is hypothesized to be a major conduit for thermogenic hydrocarbons to reach the shallow sediments [ Macelloni et al ., ] and a likely site to find disseminated hydrate [ Simonetti et al ., ].…”