Fire & Ice

Sveifluhals,Iceland- Tens of thousands of years ago this place was the heart of a roiling volcanic eruption.

Molten rock bubbled up from a fissure in the Earth's crust. On top of that lay hundreds of meters of ice.Lava met ice, and the result was an inferno!

Heat from instanly boiled ice to steam, wich ramped up the eruptive power like a pressure cooker blowing its top. Magma hitting the steam exploded into tiny fragmented bits, sending pillars of fine-grained ash hovering overhead. It would have resembled the scene many people heard about on the news this spring- a volcano that erupted an hours drive to the east, in a place known as Eyjafjallajokul.

Eyjafjallajokul began erupting on March 20 but few people other than volcanologists and locals took notice at first. For weeks all it did was spurt lava gently out of exposed ridge.

On April 14,though, the eruption suddenly shifted a few kilometers west-no longer on open land , but beneath an ice cap. Just as happened at Sveifluhals, magma met ice and turned it to steam, throwing ash into the stratosphere. European airline flights shut down for days over worries about how the ash might affect jet engines.

What a difference a little ice makes! Had the second phase of the eruption not shifted westward, the volcano would not have closed down much of Europe's air traffic

Eyjafjallajokul's eruptrion has refocused attention on a small but rapidly growing subset of volcanology: the study of volcano-ice interactions. Ice covered volcanoes or "glaciovolcano" are not fundamentally different from other volcanoes in terms of "plumbing" or eruptive style. But they distinguish themselves the magma breaks through the crust and meets ice.