glaciers take on lives of their own

One of the Icelandic exports is a vodka called Fire and Ice. Though I won’t comment on its quality, the name itself is of interest.

One of the Icelandic exports is a vodka called Fire and Ice.

Though I won’t comment on its quality, the name itself is of interest.

Iceland, you see, is a large volcanic island in the North Atlantic Ocean, and more than a one-tenth of its surface, or 11 per cent, is covered by glaciers.

This is, despite the fact that Iceland has a maritime climate that is surprisingly mild at lower elevations, where there is more rain than snow.

On the higher mountains and plateaus, however, perennial snowfields support numerous ice caps and glaciers.

What’s more, many of Iceland’s glaciers are situated atop active volcanoes.

Iceland is, therefore, a natural laboratory in which to observe the interaction of glaciers, climate, volcanoes, and the resulting sediments and landforms.

During the last ice age, almost all of the country was covered by permanent snow and glacier ice, but today, three main glaciers exist in Iceland, along with several smaller ones.

These ice caps have all shrunk significantly during the 20th century, and at least one has completely disappeared.

One of the gems is Vatnajökull, Europe’s largest ice cap. Not only that, it is also one of the world’s largest glacier, at 8,300 square kilometres.

Its highest point, which is also Iceland’s highest point, is just under 2,000 metres. One of its southern outlets, Breitamerkurjökull, descends to sea level.

Snæfellsjökull, of 11 square kilometres, is another famous glacier. It’s only a small one, but it offers a fascinating sight from Reykjavík bay at sundown in clear weather.

This glacier is best known for supplying the French writer Jules Verne’s with his opening to the centre of the Earth in his novel, Voyage to the Centre of the Earth.

The size and extent of glaciers are determined by the climate of a region, and interestingly, almost all types of glaciers are found in Iceland, ranging from the small cirque glaciers to extensive glacier caps reminding one of the inland ice of Greenland.

The smallest ones are confined to mountain valleys called valley glaciers or alpine glaciers. Larger masses of ice, ice caps, may cover an entire mountain range or volcano.

These may cover several thousand square kilometres. Vatnajökull, the largest ice cap in Europe, covers an area larger than the US state of Rhode Island, and is up to 1,000-metres thick in places.

Valley glaciers that drain an ice cap or ice sheet are called outlet glaciers.

But what is a glacier?

A glacier is a thick mass of ice that forms from the compaction and recrystallization of snow, and a glacier’s ice is constantly moving under the force of gravity.

Their existence is easily explained: They form simply because more snow falls in the winter than can melt in the following summer. This usually occurs in areas of high elevation and or high latitude.

With cold temperatures, the snow changes to ice, and the evaporation and recondensation of the water causes recrystallization to form smaller, thicker and more spherical grains of ice. This recrystallized snow is called firn.

As more snow is deposited and becomes firn, the pressure on underlying grains increases.

When the thickness of the snow and ice exceeds tens of metres, the weight is sufficient to cause the firn to grow into even larger ice crystals.

It may only take a few years for snow to be transformed into ice in glaciers where melting occurs in the zone of snow accumulation

In contrast, in places like Antarctica where there is little or no melting, it may take hundreds of years to change the snow into ice.

Iceland’s continuous volcanic heat and occasional sub-glacial eruptions give rise to unusual conditions, both for the glaciers and the volcanoes.

Due to frequent eruptions, Iceland’s glaciers contain a high content of volcanic ash — tephra.

In addition, among the most dramatic results of the eruptions are jökulhlaups, sudden outbursts of subglacial melt-water in massive floods.

Jökulhlaups are powerful agents of erosion, transportation and deposition beneath and beyond glaciers.

Broad, barren outwash plains, called sandurs, mark the regions inundated by frequent jökulhlaup floods.

One cannot live on the sandurs. It’s too dangerous.

To help prove that point: In large areas near Vatnajökull, the only road around the country can be blocked off either due to the danger of a jökulhlaup, which can sweep kilometres of the road out to sea, or, more often, due to heavy sandstorms.

These can quickly ruin the paint on your car, in which case it’s good to know that insurance agents in Iceland don’t cover such damage, calling it an “act of God”.

But as Canadians are well aware, global warming may be bringing an end to the glaciers as we’ve known them until now.

Do not despair.

The vodka will likely remain.