Mount Everest is often talked about as something truly enormous due to its height above sea level. But has anyone ever tried to weigh it?
Mount Everest weighs around 350 trillion pounds or 175,000,000,000 tons. That’s about 200,000 Golden Gate bridges.
But how does anyone know that? How do you weigh a mountain?
How Heavy is Mount Everest?
Mount Everest weighs:
350 trillion pounds
or 175,000,000,000 tons
or 175,000,000,000,000 kgs (source: the Cold Wire).
How do you calculate such a thing? Well, when trying to survey the Mason-Dixie line between the US states of Pennsylvania and Maryland, the surveyors found strange errors creeping in.
British scientist Henry Cavendish realised that the plumb lines of the theodolites and the fluids in the spirit levels were being pulled towards the nearby Allegheny mountains by gravitational attraction, producing the errors. In a flash of inspiration he realised that if you could weigh a mountain you could weigh Planet Earth.
After much searching a mountain in Scotland was chosen, Schiehallion in Perthshire. This was isolated and nearly symmetrical in shape. The mountain was first surveyed at a thousand points and mapped, with lines joining points of the same altitude. As a result the now-familiar contour lines on maps were invented during this survey. The volume, density, and then weight could therefore be calculated.
The experiment included measuring the tiny deflection of a vertical pendulum bob due to the gravitational attraction of Schiehallion. The weight of Planet Earth was then calculated at 13,170,000,000,000,000,000,000,000 pounds (or 5,974,000,000,000,000,000,000,000 kilograms). It turned out to be denser than a rock mountain and so it was realised that Earth must have a metallic core.
Eventually the Great Trigonometrical Survey, using these techniques determined that Mount Everest was the highest mountain in the world (source: NatGeo)
What’s the Mass of Mount Everest?
In everyday life we use the terms mass and weight interchangeably, but strictly speaking mass is the amount of matter in an object measured in kilograms (Kgs), and weight is the force due to the pull of gravity on an object.
Weight is a force and is measured in Newtons (N). So if Mount Everest was blown off the earth into space by a volcanic eruption it would be weightless as it orbited the earth but Everest would still have a mass of 175,000,000 million kgs.
Any mountaineers still clinging to it would be very slightly attracted to the mountain by its gravitational force.
What’s The Volume of Mt Everest?
About ninety cubic kilometres. That’s about the same as an Everest-shaped pile of rock.
How Wide is Mount Everest (At the Base and Top)?
Everest is shaped like a three-sided pyramid. The very top is a point, so it has no dimensions. This thought led to the Medieval debate about how many angels could stand on the point of a pin.
But when I stood on the summit of Mount Everest on 6 October 1993 I reckoned the snow cone forming the top was about the size of a dining table, or six feet by 3 feet.
The base is harder to quantify as the mountain blends into neighbouring mountains. From the north it looks about five miles wide, though.