Arctic News: Lake Baikal

Showing posts with label Lake Baikal. Show all posts

Wednesday, December 21, 2016

Lake Baikal

The amount of methane stored in the form of hydrates at the bottom of Lake Baikal in Siberia is an estimated 1 trillion m³, which translates into 424 trillion kg of methane, or 424 Gt of methane. By comparison, the amount of methane in the atmosphere is about 5 Gt.

Aral Sea

Methane hydrates remain stable under a combination of sufficiently low temperatures and sufficiently high pressure. The temperature of the water at the bottom of the lake is about 3.5°C. This means that a large amount of water needs to remain present in the lake at any time, in order to keep the methane hydrates stable.

Lake Baikal is the world's deepest lake. Due to its depth, Lake Baikal is also the largest freshwater lake by volume in the world, containing roughly 20% of the world's unfrozen surface fresh water. Lake Baikal has 23,615.39 km³ (5,700 cu mi) of fresh water and a maximum depth of 1,642 m (5,387 ft).

If the water level in Lake Baikal were to fall, the pressure on the methane hydrates would decrease, resulting in huge methane eruptions, dwarfing the amount of methane currently in the atmosphere.

What are the chances that water levels in Lake Baikal will fall in future? The above animation shows the fate of the Aral Sea, further to the west in Asia (also on the map at top). The Aral Sea virtually disappeared over the course of the last few decades. Some people point at climate change as the cause. More people point at irrigation by farmers.

Yenisei River

Lake Baikal could go the same way. Climate change may well reduce the flow of the rivers that now feed Lake Baikal from Mongolia (image right). Furthermore, climate change may well reduce crop yields worldwide as well as the availability of fresh water, increasing temptations to use the water of Lake Baikal for irrigation.

Further decline of Arctic sea ice is likely to push up temperatures across Russia. The image below shows that temperatures as high as 36.6°C or 97.8°F were forecast for June 13, 2016, over the Yenisei River in Siberia that ends in the Arctic Ocean.

[ click on images to enlarge or go to original post ]

Even higher temperatures were recorded in 2015 at a location in Siberia well within the Arctic Circle.

Demands for water could increase even more dramatically due to wildfires and the need to fight such fires. The image below shows that on June 23, 2016, wildfires north of Lake Baikal caused emissions as high as 22,953 ppb CO and 549 ppm CO₂ at the location marked by the green circle.