Mercury, Mars and Venus have volcanoes and faults, but as far as we know their crust behaves as a single rigid shell. Earth's is broken into a dozen or so large plates that slide, dive and get recycled into the mantle. This geological conveyor belt builds mountains and oceans, and plays a key role in the carbon cycle that regulates climate over the long term.
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.