I’ve just come back from a day trip to Vatnajökull glacier in the south-eastern corner of the country. With an area of over 8,000 km² and an average thickness of 400m, Vatnajökull is the world’s largest glacier outside the polar regions. Among the active volcanoes that lie under the ice cap is Grímsvötn, which erupted in 1996, 1998 and 2004.

The east of the country is known for its good weather and Sunday was no exception. Clear sunny skies and temperatures of around 18°C made for some pleasant conditions on the glacier, which covers around nine percent of the country. It is popular among adventure seekers for ski-dooing, hiking, ice climbing and super-jeep tours.

We went on a ski-dooing tour of the glacier. The bright, warm (+20°C, if you factor in the sun reflecting off the snow) and sunny conditions seemed a world away from Reykjavík.

The view from the top of Vatnajökull.

We also visited Jökulsárlón glacial lagoon, which lies at the southern end of Vatnajökull. Icebergs which have broken off from the glacier float in the lagoon. The scene is so spectacular that people sit in silence watching the large chunks of ice crash into the ocean and slowly make their way to the ocean nearby.

Our guide explained that the 20km² and 200m deep lagoon didn’t exist 75 years ago, but is now getting bigger as the glacier shrinks, partially due to global warming. We were told that some of the glacial ice seen floating on Jökulsárlón is around 1,000 to 1,500 years old. The half saltwater-half freshwater lagoon is home to krill, herring, salmon, trout – and seals, which can be seen dozing on the icebergs.

Vatnajökull has some other statistics worthy of a mention: it has Iceland’s lowest and highest points; wettest and driest conditions; and warmest and coldest temperatures.

You may also be wondering about the blue color of the ice – it’s an optical illusion caused by the fact that water and ice can absorb yellow and red, but not blue. Here’s how it works: Sunlight appears white, but is really made up of all the colors of the rainbow. Each of these colors has different amounts of energy in them.

The black color is caused by dust, sand and in come cases, volcanic ash.

When the sunlight shines through ice the sun gets broken down into the different colors. Red and yellow light have weak energy and are easily absorbed. However, blue light has enough energy to shine through the ice without getting absorbed. So the blue color we see in Jökulsárlón and elsewhere is the result of the blue light having escaped absorption.

When ice is affected by air pockets or is exposed to air for a long period of time, it appears white. This is because the white light of the sun, which is actually comprised of the full spectrum of  light from the sun, is reflected at the boundary between ice and air, leaving snow and exposed icebergs to appear white.

You really do learn something every day.

ZR – zoe_robert3@hotmail.com