A 'methane bucket' capture device added to the front of the remotely operated vehicle with gas hydrate at the top of the cylinder. During ascent, the hydrate was seen to sublimate into gas and expand in volume, filling the gas cylinder. Image courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico 2012. Download larger version (jpg, 1.6 MB).
The fourth remotely operated vehicle (ROV) dive of the cruise was conducted today at the Pascagoula Salt Dome to quantitatively assess the flux of gas from a natural seafloor gas seep. The ROV descended to a known seep approximately 1,125 meters deep and captured rising gas bubbles in a 'methane bucket' over a known period of time, until the cylinder was 10-20 percent full. As the gas bubbles were captured, gas hydrate was observed forming at the top of the clear acrylic 'methane bucket.' The ROV then ascended through the water column with the gas hydrate, and during ascent, the hydrate was seen to sublimate into gas and expand in volume, filling the gas cylinder.
