Along the Atlantic coast of southern Africa, the Namib Desert is thought to have been arid or semi-arid for at least 55 million years, making it the oldest known desert. It barely ever rains, but a cold ocean current creates coastal fogs that bring the moisture plants and insects depend on. Some of its red dunes rise more than 300 m.
On 27 August 1883, the eruption of the Indonesian volcano Krakatoa was heard as far away as Rodrigues Island, nearly 4,800 km away. Its pressure wave was picked up by barometers worldwide and circled the globe several times. The tsunamis that followed killed more than 36,000 people.
The deepest known point in the ocean, Challenger Deep, lies roughly 10,900 m below the Pacific surface. Drop Everest in and its summit would still sit about 2 km underwater. Down there, the pressure is more than 1,000 times what you feel at sea level, roughly a tonne pressing on every square centimetre.