A study by German and Swiss scientists published in the journal Nature Geoscience has disclosed that earthquakes not only trigger landslides and tsunamis and do massive damages to infrastructure, not to mention lives lost. They also trigger the release of damaging greenhouse gas methane from underground reservoirs.

The scientists came off with the premise based from proof of sediment cores gathered from drilling the bed of the northern Arabian Sea conducted by marine scientists in 2007 during a research trip.

Earthquakes Release Damaging Greenhouse Gas Methane in Ocean Bed – Study

Methane hydrates, described as a solid ice-like crystalline structure of methane and water, were found in one of the cores which was only drilled 1.6 metres below the sea floor.

A colorless, odourless, flammable gas that is the simplest hydrocarbon, methane gas is the major constituent of natural gas. It is released during the decomposition of plant or other organic compounds, as in marshes and coal mines.

According to David Fischer from the Marum Institute at the University of Bremen, they discovered that a major earthquake had occurred in 1945 close by the northern Arabian Sea. It was an 8.1-magnitude quake, the biggest ever detected in the area.

"Based on several indicators, we postulated that the earthquake led to a fracturing of the sediments, releasing the gas that had been trapped below the hydrates into the ocean," he said, noting the natural occurrence broke a shallow gas reservoir at Nascent Ridge.

Ultimately, this rupture had paved the release of some 7.4 million cubic metres of methane, to the surface. The authors did not identify the possible exact number of years this took.

"The quake broke open gas-hydrate sediments and the free gas underneath migrated to the surface."

What's disturbing is that the hydrates did not dissolve. "They remain there," Mr Fischer said.

He therefore experts studying the global weather warming phenomenon to consider quake-released methane as another cause of climate change.