A study shows that the moon controls tidal changes in the earth's oceans and the release of methane from the Arctic seafloor. Previously, people may not know much about the continuous release of a large amount of greenhouse gas methane from the bottom of the Arctic Ocean. This phenomenon has lasted for thousands of years. With the increase of ocean temperature caused by global warming in the future, the release of methane from the bottom of the ocean will be further intensified. These gases can escape from the ocean and become part of the greenhouse gas in the atmosphere. This is what scientists are trying to do One of the most important mysteries solved by graph.
In the past few decades, the total amount of methane in the earth's atmosphere has increased significantly. Although it can be partly attributed to human activities, in fact, human beings have not fully controlled methane from other sources, or even mastered how methane is produced in the atmosphere.
Small pressure changes affect methane release from the Arctic Ocean
The moon controls one of the most powerful natural phenomena on earth - the tides that shape the earth's coastline. Conversely, tides can significantly affect the intensity of methane release from the seabed of the Arctic Ocean A large amount of methane gas is accumulated in the sediment within meters. Even if the water column has a slight pressure change, it will easily affect the methane gas release. Low tide activity means that the hydrostatic pressure is smaller and the methane release intensity is higher. Rising tide will lead to the increase of sea water pressure and the decrease of methane gas release intensity at the bottom of the sea. "
"This is the first time such observations have been made in the Arctic Ocean, which means that small pressure changes caused by tides can release large amounts of methane gas from the bottom of the ocean," said Jorgen kenis, another author of the study
A new method to reveal the unknown release area of methane gas from seabed
By placing a tool called a piezometer in the sediment layer of the seafloor for four hours, faverola points out We can measure the pressure and temperature of the water in the pores of the sediments by observing the sea bottom in the next few days. The pressure and temperature changes measured every hour show that the gas near the bottom will rise and fall with the tide changes. This seabed survey was carried out in the Arctic Ocean. Except for the gas hydrate samples collected in this area before, no methane gas release was observed.
He said that the latest research tells us that methane gas released from the seabed is more extensive than that measured by traditional sonar technology. We don't see bubbles or gas columns in the water unless there is a permanent monitoring tool, such as piezometer.
Here, the operator is recovering the pressure tool manometer, which monitors how methane gas is released from the seabed sediments.
These observations suggest that the current quantitative level of gas emissions in the Arctic region may be underestimated. However, high tide seems to affect greenhouse gas emissions in the Arctic seabed region by reducing water surface height and sea water volume.
The latest discovery is unexpected and of great significance. This is a deep-sea area. Small changes in pressure will increase the release of greenhouse gases. However, due to the deep water, most of the methane gases remain in the sea. But what will happen to the shallow seabed? This method also needs to be carried out in the Arctic shallow water area, and it will last for a long time. In the shallow water area, methane gas is more likely to enter the atmosphere.
Can sea level rise caused by climate warming offset the release of methane from the seabed?
Under the action of tides, the deep-sea area may reduce the water surface height and volume, thus affecting the emission of greenhouse gases from the seabed. However, the question is whether the sea-level rise caused by global warming may partially offset the impact of temperature on the emission of methane from the seabed?
"At present, we are deciphering the subtle and mysterious interconnections between the earth systems, and our research will reveal one of the interconnections in the Arctic waters - the moon causes tidal forces, tides produce pressure changes, ocean currents reshape the seabed environment, and affect the release of methane from the seabed," faverola said