Detecting gas hydrates in ocean sediments
Gas hydrates present an opportunity as a source of energy, but also a threat if the methane gas escapes to the Earth's atmosphere where it will intensify global warming. Our knowledge of gas hydrates is limited, but the multi-year project entitled ANAXIMANDER sought to rectify this situation. During ANAXIMANDER marine geologists with the Instituto Ciencas del Mar (ICM) in Barcelona developed advanced techniques to locate and quantify gas hydrate reserves. Gas hydrate formation is associated with mud volcano activity at the bottom of the sea. ICM consequently analysed sediment cores from the Eastern Mediterranean in search of mud volcano artefacts. The Spanish scientists correlated mud volcanic events with specific lithostratigraphic features they found in the sediment cores. For instance, by measuring the number and distribution of mud breccia layers and individual clasts or the trends in grain size, ICM was able to extrapolate the number, frequency and intensity of mud flow events. Scanning Electron Microscopy (SEM) was integral to this phase of the ANAXIMANDER research programme. ICM then built upon this knowledge to establish the available gas hydrate reserves resulting from the local mud volcano activity. Finally, the methodology was verified with additional sediment cores from the Gulf of Cadiz, another region home to undersea volcanic activity.
