Imagine solving prehistoric mysteries by sifting through the ashes of ancient volcanoes.

It's one of the biggest mysteries of recent human evolution. Roughly 70,000 years ago, Homo sapiens went through a genetic bottleneck, a period when our genetic diversity shrank dramatically. But why? In the late 1990s, some scientists argued that the culprit was a massive volcanic eruption from what is now Lake Toba, in Sumatra, about 74,000 years ago, whose deadly effects reduced our species to a few thousand hardy individuals. Now, new evidence suggests we were right about the volcano—but wrong about pretty much everything else.

Water may be more common than expected at extreme depths approaching 640 kilometres and possibly beyond -- within Earth's lower mantle, says a study that explored microscopic pockets of a trapped form of crystallised water molecules in a sampling of diamonds from around the world.

Early humans survived a massive volcanic eruption 74,000 years ago as well as flourished during the resulting climate change, finds a new study.

Water may be more common than expected at extreme depths approaching 640 kilometres and possibly beyond — within Earth’s lower mantle, says a study that explored microscopic pockets of a trapped form of crystallised water molecules in a sampling of diamonds from around the world.

Diamonds are a geoscientist’s best friend — this is especially true for a group of researchers who recently found hard evidence that water exists deep within Earth’s mantle by examining diamonds from around the world.

To most of us, ice is just ice. But scientists have categorized no less than 16 types, created under different conditions and featuring different crystalline structures. Most of these have only been created in the lab, but now, geoscientists at the University of Nevada Las Vegas (UNLV) have discovered a type known as Ice VII (seven) locked inside diamonds. This marks the first time the substance has been directly detected in nature, and it suggests that the Earth's mantle is home to huge pockets of water.

Around 74,000 years ago, the Toba supervolcano erupted on the Indonesian island of Sumatra. It was the biggest volcanic eruption of the last 2 million years, unleashing 2,800 cubic kilometers of magma. That’s enough to bury the entire United States in a foot-thick layer of ash and rock.

Imagine a year without summer. The sky turns gray during the day and glows a sinister red at night. Trees wither and start to fall, all vegetation dries down and becomes a desolate shadow of its former self. Animals also start to suffer and thin down, and the damage propagates up the food chain, wiping out entire ecosystems. The same cycle repeats year after year, with no visible end in sight.

The team, led by University of Nevada, Las Vegas geoscientist Oliver Tschauner, found inclusions of the high-pressure form of water called Ice-VII in natural diamonds sourced from between 255 and 410 miles (410-660 km) depth.

Scientists have stumbled upon an entirely new type of water that they are calling Ice-VII, and they believe it is being caused by diamonds deep in the crust of the Earth. The extraordinary discovery could change our understanding of fluid pockets that reside hundreds of miles below the surface of the Earth.

A team of researchers has discovered ice crystals in a diamond. Probably not a huge discovery, you may think, but this ice, names Ice-VII, is coming from the Earth’s mantle and has been supposed, until now, that it only naturally exists on other planets and their moons and can only be made in a lab.