Methane leakage from the environment and human activities is a serious greenhouse gas problem. Methane is many times more effective than carbon dioxide at retaining heat, and scientists now say the moon plays a key role in how much of the gas is released.
It all has to do with the tides and the pulling effect that the moon’s gravity has on them – a phenomenon we can quantify. Placing a piezometer instrument in the Arctic Ocean for four days and nights allowed researchers to measure temperature and pressure changes over time.
What they found was that the presence of methane gas close to the sea floor rises and falls with the tides, which is a major contributing factor when it comes to the release of methane, and one that is impacting the climate change we see now and in the future. see. .
The piezometer is being picked up. (P. Domel)
“We have found that gas deposits, located in the sediments within one meter of the seabed, are vulnerable to even slight pressure changes in the water column,” said marine geophysicist Andreia Plaza-Faverola from the University of Tromsø – The Arctic University of Norway. .
“Low water means less of such hydrostatic pressure and a higher intensity of methane emissions. High water equals high pressure and lower intensity of emissions.”
These methane leaks in the Arctic Ocean have been occurring for thousands of years, caused by factors such as seismic and volcanic activity, but there is much more to learn about the mechanisms that cause this spill and affect its rate.
That’s where the moon and the tides come in. The researchers say tides could be used as a way to predict the amount of gas released from the Arctic Ocean from day to day, even with tidal height variations of less than 1 meter (3.3 feet). ).
One thing we can remember is that the release of gas from the seafloor is more widespread than the data from conventional sonar surveys shows, and we may have underestimated how much gas the North Pole is leaking right now, even if it doesn’t get all at once. released.
“Earth systems are interconnected in a way that we are still deciphering, and our study reveals one such interconnection in the Arctic,” said Plaza-Faverola.
“The moon creates tidal forces, the tides generate pressure changes and bottom currents that in turn determine the sea floor and influence the methane emissions under the sea floor.”
The study also raises the possibility that sea-level rise could reverse the release of methane from the oceans, as the greater water pressure retains the gas longer. It’s just one of the many factors scientists have to weigh.
Next, the researchers want to capture more data over a longer period of time to see how changes in tides affect the release of methane in the region as a whole: from deepwater locations like this one to shallow water areas where the effect of tidal variations on gas release is likely to be even greater. .
Although past tidal changes have been linked to methane emissions, the geographic location of this study and the fluctuations observed by even small differences in pressure make it a crucial new point of information for future modeling of climate change.
“It is the first time this observation has been made in the Arctic Ocean,” says marine geologist Jochen Knies.
“It means that small pressure changes can release significant amounts of methane. This is a game-changer and the biggest impact of the research.”
The research is published in Nature Communications.