A team of Russian scientists successfully reached the bottom of Siberia's Lake Baikal, the world's deepest. Lake Baikal was declared a UNESCO World Heritage Site in 1996. It contains more that 20% of the world’s freshwater. It is not only the deepest, but is also the oldest. It was formed after a massive earthquake around 25 million years old.
The safe return of 2 submersibles (Mir-1 and Mir-2) set a new record by descending 1680 meters. Before this, it was thought that Lake Baikal was only 1637 meters deep. They were taking samples from the bottom to further their studies of plants and animals.
Some skeptics might argue that they were really examining potential entrance paths for oil. Igor Chestin, the head of WWF Russia, commented on possible oil exploration by saying, "I think scientists as well as the politicians are enough educated to understand that even if all oil of the planet will be down the lake Baikal, it still will not be worth exploring, because the fresh water is going to be the major resource in the coming decade."