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How long will it be until the pyramids in Egypt weather away completely?

Mark Thompson
Tewkesbury, Gloucestershire, UK

The Great Pyramid of Giza, built on the orders of Khufu (Cheops) in 2540 BC, is the numero uno of pyramids, with superior materials, engineering and design know-how to any built before. Ancient Greek tourists would travel thousands of miles to stare at its towering limestone steps.

Cleopatra lived closer in history to the construction of today’s tallest building – the Burj Khalifa – than she did to that of the Great Pyramid. When the last mammoths died out, it was already several hundred years old.

It is less a building than an artificial mountain, made of nearly 6 million tonnes of solid rock. Five thousand years is no time whatsoever when you consider the limestone had been lying in the ground for 50 million years or so. So what will cause its destruction?

A meteor strike? Let’s hope not, as that wouldn’t bode well for humanity.

An earthquake? There have been several over the time since it was built, but the only one that affected the pyramid took place on 8 August 1303, loosening many of the outer casing stones.

The Great Sphinx of Giza may have been blown into shape by the wind

As rock is carved by the wind, it can take on a sphinx-like shape, meaning the Great Sphinx in Egypt may have been partly formed through natural processes

Weathering? The engineers shaped the stones to incredible tolerances to prevent the freeze-thaw effect on the rock. However, one estimate is that the erosion is about 0.1 centimetres per decade, which is approximately 1 metre every 10,000 years.

Global warming? It could raise the floodplain, or it could add to the intensity of the freeze-thaw erosion rate. But even so, it will take a long, long time (unless we humans really screw things up).

Another thing to note is that a stone pyramid is hard to beat for stability. There is almost no way for it to collapse, given a stable base, and it can’t burn down.

Hidden corridor in Egypt’s Great Pyramid mapped with cosmic rays

A 9-metre-long corridor in the 4500-year-old Great Pyramid of Giza that was discovered in 2016 has now been mapped, and researchers have used a tiny camera to peer inside

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