A collaboration between the National Oceanography Centre (NOC) and the University of Southampton is to develop an instrument capable of simulating the high pressures and low temperatures needed to create hydrate in sediment samples.
Dr Angus Best of NOC and Professors Tim Leighton and Paul White from the University of Southampton's Institute of Sound and Vibration Research (ISVR) have been awarded a grant of 0,8 million by the Natural Environment Research Council (NERC) to investigate methods for assessing the volume of methane gas and gas hydrate locked in seafloor sediments.
Dr Best, who is leading the project, explained: "Greenhouse gases, such as methane and carbon dioxide, are trapped in sediments beneath the seafloor on continental shelves and slopes around the world. Currently, there are only very broad estimates of the amount of seafloor methane and hydrate."
The team plan a series of experiments on a range of sediment types, such as sand and mud. They intend to map out the acoustic and electrical properties of differing amounts of free methane gas and frozen solid methane hydrate.
The laboratory-based approach adopted by the team will involve the development of a major new Acoustic Pulse Tube instrument at NOC. Using acoustic techniques and theories developed by the ISVR team, they aim to provide improved geophysical remote sensing capabilities for better quantification of seafloor gas and hydrate deposits in the ocean floor.
"Not much is known about the state of gas morphology bubbles. Muddy sediments show crack-like bubbles, while sandy sediments show spherical bubbles. Only dedicated lab experiments can hope to unravel the complex interactions. By creating our own 'cores' of sediment material in a controlled environment where we know the concentrations of methane or carbon dioxide, we can create models to help us with in situ measurements on the seafloor."
There is significant interest in
|Contact: Kim Marshall-Brown|
National Oceanography Centre, Southampton (UK)