2024-07-27 18:43:02
Lake Kivu is one of the Great Lakes of Africa, located at the boundary of the tectonic plates known as the East African Rift. In the rift, the Somali tectonic plate is drifting east and away from the rest of the continent, the Nubian plate. (The Nubian plate is sometimes also called the African plate). Because of this movement there is volcanic and seismic activity in the regionwhich in turn transfers gas from the depths of the Earth’s crust to the surface – and to the depths of Lake Kivu.
Lake Kivu is much larger than Lake Nyos or Lake Monoun: it is 90 km long, 50 km wide and up to 475 m deep. The lake has an unusual layered structure, as only the upper 60 m deep layers regularly mix the water – while the lower layers are static, „National Geographic“ sako Sergey Kacev, professor of physical and geochemical limnology at the University of Minnesota Duluth (USA). Such a strict separation means that the CO coming from the bottom of the lake2 and methane is trapped and accumulated in the lower layer at depths of 260 m and below.
The bottom of Lake Kivu contains approximately 300 cubic kilometers of CO2 and 60 cubic kilometers of methane, says S. Kacevas, and hydrogen sulfide gas from the depths of the Earth’s crust also enters here.
And this toxic cocktail could soon explode in the surrounding densely populated region, Kacev said.
The explosion would release a huge cloud of gas that would hang over the lake for days to weeks and eventually dissipate into the atmosphere, Philip, an engineer and founder of Hydragas Energy, a Canada-based company that plans to extract methane from Lake Kivu to generate electricity, told National Geographic. Morkel. “When the lake reaches 100 percent saturation [dugno sluoksnyje]and at the moment it is about 60%, it will resolve itself”, says the specialist.
According to him, at that time, the lake could release 5 percent in one day. of the world’s annual greenhouse gas emissions. The death toll from such an explosion would be staggering. About 2 million people live on the shores of Lake Kivu. people, and “if someone were to be in that cloud, it would take a minute to kill them.”
While scientists can determine how much gas is in the lake and thus assess the risk of an explosion, other, less predictable factors could also cause a catastrophe. For example, an earthquake or a sudden intrusion of lava can disturb the layers of the lake and cause an eruption, says S. Kacevas.
Current efforts to pump methane out of the lake could also pose risks, he notes. Methane production 2016 started on the Rwandan side., in order to reduce the risk of explosion and at the same time supply energy to the country’s power grids. But some experts warn that by damaging the lake’s structure, the operation could lead to the very explosion it is trying to prevent.
“This is a compromise between security and commercial use in the long term,” says S. Kacevs. Extraction companies pump water from the lower layer, remove the methane and return the degassed water to the upper layer. “As the water sinks down, it creates a flash,” which increases the risk of an explosion, the scientist said.
Parengta pagal „Live Science“.
2024-07-27 18:43:02