Between 1993 and 2010, humans extracted around 2,000 billion tonnes of groundwater, most of which ended up in the oceans. Shifting that much mass changed how the planet's weight is distributed: according to a 2023 study, Earth's rotational pole drifted by about 80 cm. The pumping also raised sea level by around 6 mm.
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.