Lake Baikal is so deep because it has formed in a rift valley, that is the crack where the continental crust is ripping apart. At the bottom of Lake Baikal lies another 7km worth of sediment before reaching the rift floor, the deepest continental rift on Earth (via Invernomuto su FB/FdM) https://www.reddit.com/r/... https://i.imgur.com/QSYxJ...
