Volcanic eruption becomes Iceland’s longest in five decades

The volcanic eruption mesmerising spectators near Reykjavik began six months ago on Sunday, making it the longest Iceland has witnessed in more than 50 years.

Lava started spewing out of a fissure close to Mount Fagradalsfjall on the evening of March 19 on the Reykjanes peninsula to the south-west of the capital city.

And the ensuing spectacle – ranging from a slow trickle of lava to more dramatic, geyser-like spurts of rocks and stones – has become a major tourist attraction which the Iceland Tourist Board says has drawn 300,000 visitors.

Iceland's sixth volcanic eruption in 20 years has already lasted longer than the preceding one in Holuhraun, in the centre-east of the island, which lasted from the end of August 2014 until the end of February 2015.

“Six months is a reasonably long eruption,” volcanologist Thorvaldur Thordarson told AFP.

The lava field that has formed this time has been called Fagradalshraun – which can be translated as “beautiful valley of lava” – and takes its name from nearby Mount Fagradalsfjall.

Almost 143 million cubic metres of lava have spewed out so far.

But this is comparatively small, representing slightly less than a tenth of the volume of the Holuhraun eruption, which emitted Iceland's biggest basalt lava flow in 230 years.

The latest eruption is “special in the sense that it has kept a relatively steady outflow, so it's been going quite strong”, said Halldor Geirsson, a geophysicist at the Institute of Earth Science.

“The usual behaviour that we know from volcanoes in Iceland is that they start really active and pour out lava, and then the outflow sort of decreases over time until it stops."

Iceland's longest-ever eruption took place more than 50 years ago on Surtsey island just off the southern coast and lasted from November 1963 until June 1967.

No end in sight

After subsiding for nine days, the lava reappeared at Fagradalshraun in early September, occasionally spurting red-hot from the crater and accompanied by a powerful plume of smoke.

It accumulated in fiery tunnels beneath the solidified surface, forming pockets that eventually gave way and unfurled like a wave on to the shore.

The number of visitors trekking to the rough hills to view the spectacle is probably even higher than the estimated 300,000, as the first counter installed on the paths leading to the site was set up only five days after the eruption.

In the first month, 10 fissures opened up, forming seven small craters, of which only two are still visible.

Only one crater is still active, measuring 334 metres, the Institute of Earth Science says, and lies a few dozen metres short of the highest peak in the surrounding area.

But the eruption is showing no sign of fading.

“There seems to be still enough magma from whatever reservoir the eruption is tapping. So it could go on for a long time,” Mr Geirsson said.