BERLIN (TIP): Earthquakes may contribute to global warming by releasing methane, a highly potent greenhouse gas, from the ocean floor, according to a new study. An international team of scientists investigated the aftermath of a magnitude 8.1 earthquake that took place in the Northern Arabian Sea in 1945. They postulated that this event caused the release of about 7.4 million cubic metres methane, into the ocean. In 2007, during a research cruise off the coast of Pakistan, the scientists obtained several sediment cores.
One of these cores contained methane hydrates, a solid ice-like structure of methane and water, just 1.6 metres below the sea floor. Investigations of these enabled the scientists to relate the 1945 earthquake to the concomitant release of methane , researchers said. Scientists from the MARUM Institute at the University of Bremen, the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Bremerhaven , and the ETH Zurich investigated hydrocarbon cold seeps at the Pakistani continental margin. During their expedition with the research vessel METEOR , the researchers extracted sediment core samples , which they closely investigated in the lab.
“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,” said first author Dr David Fischer The conservative estimate of the methane released since the earthquake, not taking into account how much was discharged directly after the quake, is equivalent to roughly 7.4 cubic metres of methane gas at standard conditions at the earth’s surface, which equals 10 large gas tankers.