This warm current, which hugs North America's east coast before crossing the Atlantic, moves tens of millions of cubic metres of water every second. That dwarfs the combined flow of every river on Earth, the Amazon included. Part of its tropical heat is then released into the atmosphere, helping to soften the climate of whole regions.
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.