Gulf Stream warm currents are releasing methane from the sea floor

A large amount of bio-carbon on Earth is stored under the seabed as methane hydrate, a frozen mixture of methane and water. This mixture is formed at high pressure and low temperature conditions.

The change in temperature or direction of warm ocean currents from the Gulf of Mexico (Gulf Stream) has increased the temperature of the regional subsurface sediments along the North Atlantic Ocean by 8 degrees Celsius. This led to the release of 2.5 billion tons of methane gas from seabed sediments. Scientists reported on October 25 in the journal Nature.

'This is the first study to show that the melting of methane hydrate related to ocean currents itself,' said co-author Benjamin Phrampus, Southern Methodist University Earth scientist in Dallas. previously said that global ocean temperatures would have to be increased in order to cause hydrate disruption, which would require a huge input of energy , " he said. " We don't need the amount of energy. Large above to explain this. It is simply a change in the ocean's flow. "

In his 1963 novel 'Cat's Cradle' (Kurt Vonnegut 's Cat's Cradle ) wrote about a fictional substance methane hydrate, crystallizing all the liquid water that it collided with the power to wipe out all life. on earth immediately. While methane is a much more greenhouse gas than CO2, at the depth where it is being released, most methane will never fly to the air. Instead, it will dissolve in seawater, where the bacteria will convert methane into CO2. Even if methane reaches the surface, it only exists in the air for about 10 years.

In order to affect global warming, a lot of methane gas is added to the atmosphere. geophysicist Carolyn Ruppel of the US Geological Department in Woods Hole, Massachusetts. However, if sediments retain methane, it may make the underwater slopes more prone to landslides. These slides can release more methane gases from the sea floor or activate tsunamis.

Unstable hydrates may have caused the terrible Cape Fear slide in the North Atlantic region, and similar slides could release a greater amount of gas than previously released gas.

Suddenly releasing methane hydrate has been proposed as the cause of Paleocene-Eocene global warming events (PETM), This event occurred about 55 million years ago, when global temperatures have increased 5 degrees C. Compared to PETM, the total amount of gas released from the hydrate destruction of the east coast of the United States is very small, Phrampus said, but he also notes that it does not seem like this is just a part. of the world where the phenomenon is happening.

The conclusions about degraded hydrates are based on indirect measurements of seabed temperature.

Hydrate methane can only form in a few hundred meters at the top of marine sediments. Under this part, the earth's geothermal heat holds methane gas. Seismic signals are related to the depth where solid hydrates meet methane gas.

Compare this depth with theoretical predictions that the area might be cool in the past, but changes in the Gulf Stream 5,000 years ago are causing it to heat up.

It's like seeing an ice cube on a warm sunny day, said Gerald Dickens of Rice University in Houston, Houston. 'You can deduce that ice is melting even if you don't see it. According to the same logic, from increasing the temperature of sediment scientists suspect that a large chunk of frozen methane is evaporating '.

Methane methane will be destroyed in the next few centuries if the Gulf Stream does not reduce the temperature or change its position. Scientists have not yet determined the amount of methane hydrate and have not yet calculated the amount of gas they can release, so the impact of melting methane hydrate on global climate has not yet been made. clearly.