Brute force: Huge 1,000-ton boulder carried down mountainside by power of Icelandic volcano.
Towering above the landscape that surrounds it, this huge boulder is a graphic display of the awesome force created by an erupting volcano.
The 1,000-ton rock, which stands more than 50 feet high, tumbled to the valley floor after the eruption of the Eyjafjallajokull volcano in Iceland earlier this year.
The giant stone was released by ice in a glacier that melted thanks to the fantastic heat produced by the erupting volcano. The melting glacier caused a meltwater flood, which swept the rock down the mountainside with it.
A huge rock stands isolated from the main debris pile and towers over the small figure of a man. The weight could be close to 1,000 tons
Clouds of ash spewing from fissures in the volcano caused travel chaos across Europe for months as flights were grounded and holidaymakers were left stranded.
Icelandic photographer Ragnar Sigurdsson spent weeks capturing the dramatic scenes as the volcano continued to erupt, including flying over the bubbling crater.
Some of his most awe inspiring pictures show lightning storms within the darkened plume of the volcano, caused by water vapour from the nearby glacier releasing energy in response to the superheated ash cloud.
He has captured more than 10,000 images of the volcano as red hot lava was thrown into the air and compiled three book volumes entitled Untamed Nature.
Sigurdsson, 52, chose to fly into the epicentre of destruction on a mission to record the spectacular wrath of one of nature's most deadly phenomena.
He and geologist co-writer Ari Trausti Gudmundsson have now made a selection from 10,000 of Ragnar's pictures of the catastrophe.
Interest generated by their first two sell out editions of 'Eyjafjallajokull: Untamed Nature', spurred the duo to add new personal accounts, giving fresh insight into the drama, in their brand new third edition.
Lightning is seen in the large eruption clouds at the Eyjafjallajokull volcano, Iceland. Static charges build up in the cloud until lightning flashes and releases a charge.
Traveling Iceland in a converted military Land Cruiser Ragnar was able to record spectacular and unique images of the Icelandic eruption as it unfolded on a global scale.
‘Once all the airports started shutting down I knew this was a major story of global significance,’ said 52 year-old Ragnar, from Iceland.
‘This eruption clearly had a great impact on the whole world.
‘However, because of the intensity of the experience it was actually a rush for me and was exciting to be involved in such a hands-on way.
‘Getting the very best shots I can is a great reward. Personally my favourite picture is an aerial shot of the crater taken while flying at low altitude, in high wind speeds and the door of the plane taken off so I didn't have to shoot through glass.
Huge clouds loom over the volcano as more lightning crackles
‘I could feel the heat of the volcano against my face as we made our pass.
‘It was taken with a telephoto lens and an extremely high ISO, which can make pictures grainy, but it turned out to be a pin sharp shot. I couldn't have been more pleased.’
Ragnar Th. Sigurdsson specialises in dramatic volcano photographs
But Ragnar's profession is not without danger, with many photographers perishing in powerful eruptions.
The 1980 eruption of Mount St. Helens famously killed National Geographic photographer Reid Blackburn.
In 2008 German volcano photographer,Thomas Reichart also died while attempting to photograph Mount Etna.
‘You can never really say you know when it's safe,’ said Ragnar. ‘I always just get a feeling from my experience with volcanoes that it's safe to stay or time to go.
‘And when it's time you make sure you get out of there.’
Ragnar's and wife Asdis Gissurardottir travel together on all their trips.
‘We're a team and it's important that we make all our decisions together,’ said Ragnar.
Eyjafjallajokull's crater measures 1.8 miles wide and 2.5 miles across. From 3-5 March there were almost 3000 earthquakes at the epicentre of the volcano.
The ash cloud reached 55,000 ft with piping hot lava measuring an amazing 1000 degree centigrade spewing 400 ft into the air.