Some volcanoes erupt at super-speeds, study suggests

A subterranean "highway from hell" enables some volcanoes to erupt at super-speed, a discovery that also offers options for predicting the danger, according to a study published in Nature.

Volcanoes disgorge molten rock generated within the mantle, the layer sandwiched between the earth's crust and fiery core. The magma gathers in a chamber beneath the volcano, progressively rising until the pressure, which can be detectable over time by rumblings at the surface, becomes too great and an eruption occurs.

Conventional wisdom has it that the mantle magma creeps upwards before it reaches the chamber, lingering for long periods several kilometres beneath the volcano.

But the research, published on Wednesday, suggests there are channels that run directly through the crust from the mantle to the magma chamber.

As a result, a volcano can be recharged and primed for action in a matter of months, and a clear danger to humans living nearby.

The evidence comes from traces of an eruption between 1963 and 1965 of Irazu, a Costa Rican strato-volcano located on the notorious Pacific "ring of fire".