Tons of methane produced from mud volcanoes

Within the seabed, there is the presence of thousands of microorganisms that play a pivotal role in the global carbon cycle. However, till now, it is very much unclear as to what extent geodynamic procedures, for instance, subduction of oceanic plates impact such microbial activity which subsequently tends to have an impact on the carbon balance. To study such effect, a team of international researchers is carrying out various analyses to understand the phenomena. The unit includes scientists from the German Research Centre for Geosciences as well.

The team made its full efforts to drill down to a depth of the core. They dug to the depth of around 200 meters into the underwater mud volcano. From the samples that they took, it was found that the microorganisms present within the sediment are highly active and they form about 90 percent of the methane that is released from such a depth. Now the authors have understood that the global methane cycle formed through the mud volcanoes have been highly underestimated. 

These underwater mud volcanoes are situated at the active plate margins. It is the position where the oceanic crust is moving beneath the continental crust. This process is in fact referred to as subduction. In such situations where the seafloor is moved beneath the continent, the upper sediment portion gets moved to the foot of the continent and after that compressed within the trailing sediment.

Within this particular sediment package, accretionary wedge, which is a liquid and the materials having a lower density is pushed upwards towards the deeper layers. As a result, mud volcanoes result in the formation on the surface of the seabed made up of thin sediment and water and gases in place of lava.

To find a valid basis for this theory, the researchers analyzed a volcano which is located in the Nankai trough, close to Japan, taking resort to Japanese drilling ship which is referred to as “Chikyu.” For this particular examination, a team of researchers led by Akira Ijiri who had come from the Research center JAMSTEC has written that the “mountain” KMV # 5 has an altitude of 112 to 160 meters above the adjoining ocean floor. The researchers have further found out that in this particular re there are 13 more mud volcanoes which are positioned beneath the Pacific Ocean.

From the depth of 200 meters deep, the researchers also identified bright fragments of gas hydrate which is a combination of methane-water compound and under a specific condition is neither liquid nor gaseous but eventually is solid.