Nord Stream: What impact the blasting will have on the Baltic Sea
A new study sheds light on the effects of sabotage on the Nord Stream gas pipelines. Large quantities of methane were released into the atmosphere.
(Image: Dänisches Militär)
Even after a year and a half, there are still many unresolved issues surrounding the attacks on the Nord Stream gas pipelines in the Baltic Sea. In addition to the still unanswered question of the perpetrators, there is also the question of the effects of the massive gas leakage as a result of the explosions in the sea. A newly published study by the University of Gothenburg attempts to shed light on this issue.
At the end of September 2022, three of four strings of pipelines between Russia and northern Germany were destroyed by detonations near the Danish island of Bornholm. The researchers based their findings on various measurements and satellite data, which they analyzed. They also differentiate between methane that is already present in the water and the fossil methane that escaped from the pipeline pipes. A distinction can be made based on the concentration of the gas. The study concludes that there were a total of three phases of release, during which a total of 300,000 tons of methane were released into the environment.
Three phases of release
In the first phase after the explosions, most of the methane was released into the atmosphere. In addition to the noticeable drop in pressure in the Nord Stream control center, the large-scale formation of bubbles in the sea, known as a whirlpool, remained in the public's memory. The researchers conclude that between 40,000 and 220,000 tons of methane were released into the atmosphere.
When the inflow from the gas pipes slowed down in the second week after the explosions, the water surface was still supersaturated with the gas and released further methane into the atmosphere. The measured values in the area of the leaks were still a hundred times higher than normal. In the third phase, the researchers expect the water to mix down to a depth of 50 meters.
Effects on marine biology
The total amount of methane dissolved in the seawater is estimated to be between 10,000 and 55,000 tons. Due to the limited number of measurements, the figures are so far apart. Methane, which is considered to be very harmful to the climate, slowly decomposes in the sea through dilution, transport by currents and methane oxidation by bacteria. In another study, Chinese researchers wrote that the total amount corresponds to just 1.3 days of the oil and gas industry's annual emissions – so despite the international furor, this is not an unusually high release.
However, the Swedish researchers do see a number of possible effects on marine biology due to the special nature of the release into the sea. The above-average amount of gas could lead to further bacteria, and the oxidation could cause the oxygen content in the Baltic Sea to drop. This would be detrimental to some marine life and would also affect the food chain. Longer-term effects cannot be ruled out either. In any case, the effects are significant and complex and require further investigation.
(mki)