On 22 May 1960, a magnitude 9.5 earthquake struck southern Chile near Valdivia, the most powerful ever recorded by instruments. The fault ruptured along nearly 1,000 km. Its tsunami crossed the Pacific and killed people as far away as Hawaii and Japan, some 17,000 km from the epicentre.
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.