For 10 points, name this lake in Siberia, the oldest and deepest in the world.
Endemic oligochaete worms and sponges live in this lake's Frolikha hot springs, and it is home to the nerpa, the only freshwater seal. Most of its Academic Range is underwater. The Holy Nose Peninsula juts into its eastern side. A Transneft pipeline was planned to pass by this lake, but was diverted north to prevent environmental damage. Its chief source is the Selenga River, while the Angara River flows out of it. An archipelago in this lake comprises Big, Narrow, Round, and Long Islands and is called the Ushkany Islands. To its south lies the North Mongolian Steppe. This lake's namesake mountain range is the source of the Lena, and it is located near Irkutsk. It contains about one-fifth of the fresh water on the Earth's surface. For 10 points, name this lake in Siberia, the oldest and deepest in the world.
Endemic oligochaete worms and sponges live in this lake's Frolikha hot springs, and it is home to the nerpa, the only freshwater seal.
Lake Baikal