The Source of The World's Most Active Volcano Might Finally Be Pinpointed

The Kīlauea volcano in Hawaii is said to be the most active volcano in the world, but we don't know how it was born.

New research suggests the original womb of magma is more than 90 kilometers away.

The original magma chamber is about 6.8 miles deep, but it seems that the larger chamber is even deeper.

A new analysis of broken fragments of ancient volcanic rock, dredged from the south-eastern flank of the Big Island, suggests that Kīlauea was born from a pool of pyroclastic material close to 100 kilometers deep.

Between 210,000 and 280,000 years ago, the Pacific tectonic plate shifted and a large shield of hot liquid burst through the sea.

The original rocks ejected from this hotspot are hard to find, buried as they are beneath newer lava.

It was thought that the volcano was created from the heat of the hotspot.

There is no evidence to support that hypothesis. The rocks were found to have a suite of rare earth elements that could only be formed in one specific way.

The volcano was formed through fractional crystallization. The creation of crystals in deep pools of magma do not react with residual melt later on.

We explored the formation of these samples through experimental work, which involved melting synthetic rocks at high temperatures and using a new method for modeling their rare earth element concentrations.

The samples could only be formed by the removal and crystallization of garnet.

The composition of rocks from Kīlauea suggests that the original eruption came from the high pressures and temperatures of the magma.

Experiments show that garnet can be formed at depths of up to 150 kilometers beneath Earth.

The original source of the Hawaiian islands may not be that deep, but the new findings suggest that the plumbing is not as superficial as we thought.

Miller says that fractional crystallization is only a shallow process and that the development of a deep 90 km magma chamber is an important early stage in the birth of a Hawaiian volcano.

Other volcanoes in the world, like Mount Vesuvius, show crystal formation times that suggest there are long-lived deep-seated magma hiding beneath the surface. The original magma chamber of Kīlauea seems to be deeper than most.

It is not clear why that is.

Nature Communications published the study.