Iceland is a magnificent example of the interplay of the four elements, and how simple principles such as hot air rising and cold sinking combine to produce a breathtaking array of nature environments, and the habitats to support complex and rare life forms. Its geology is unique in the world; nowhere else do you get a mid ocean ridge, by definition usually on the ocean floor, and a hot spot (or mantle plume) in the same place, and it is also where the Eurasian and American plates meet and are pulling apart at the same rate as finger nails growing. These two features alone are very exciting as they enable us to study at first hand, without getting too remote or wet, mechanisms that could have operated early in planetary formation.
The formation of oceanic crust is the most basic and proliferate process on Earth. Magma wells up from the mantle at constructive plate boundaries and solidifies to form the ocean floor, pushing up large underwater mountains in the process. In Iceland a ridge of this sort rises about 3000 m above the floor, emerging in the Reykanes peninsula in the tip of southwest Iceland, quite close to Keflavík airport, and zig zags across the country forming a rift zone, before plunging deep into the Arctic Ocean in the north. On this peninsula it is therefore possible to ‘hold up a trans-continental bridge’ and its almost ferocious geological activity enable us to ‘blow hot sulphurous air.’
Another famous place to see the spreading ridge at close hand is in Thengvellir National Park, easily accessible as part of Iceland’s Golden Circle. It is also the site of Iceland’s first parliament, the Alping, probably one of the oldest parliament’s in the world. And all of this on a spreading ridge between two continents.
Though basalt is a very common rock type, the varieties in which it can manifest are what gives Iceland its awesome beauty. From blocky lava fields resembling lunar landscapes, infertile and barren, olivine tholeiites have been squeezed up from the upper mantle by decompression melting. Sometimes more regulated, the basalt forms orderly layers resembling a chocolate and coffee cake, stretching for miles along ancient eruption fissures. Infertile lava and ash deserts crunch underfoot like glass, turning easily to dust, but when water is present, tiny white flowers grow in proliferation, carpeting the basalt. Gently undulating volcano slopes covered in mossy green fuzz, sometimes hues of purple, roll for miles, perfect cones loom up from rubble landscapes and others are more craggy, bearing witness to more powerful and inconsistent forms of erosion. At Myvatn, pseudocraters have been formed as a result of lava flowing over damp ground and causing it to bubble up and form cone shapes, and nearby mud pools have been formed from solidified clay.
Along the south coast, weathering and erosion has formed spectacular black sand beaches as far as the eye can see. At Vik, surely Iceland’s most beautiful beach, basalt has organised itself into its most spectacular form, that of hexagonal basalt columns, glistening like black organic pipes covered in exuberant frothy foam from the crashing Atlantic waves, and there are also rugged sea stacks just off shore to admire, one of nature’s sculpture. In the cliffs about the basalt, puffin colonies nest wheeling busily overhead as they fly out on stormy air currents above the turbulent waves. In the western fjords, it is also possible (though rare) to spot a sea eagle, and gyrfalcons can also be seen in the more mountainous areas.
Water is abundant in all of its myriad forms. Milky rivers cut their way through slate grey canyons as warmer temperatures in the summer cause water locked up in snow and ice to melt. Sometimes it forms small streams and trickles over boulders, other times wide frothing rivers gushing urgently downhill, pouring over basalt ledges and crashing into larger rocks so that it leaps in a haze of spray. Occasionally it can also be seen tumbling over volcanic cliffs in a frothy cloud, or else a tiny silver trickle. But at both Dettifoss in the north and Gulfoss in the south, water turns into a furious torrent and erupts over ledges to form the the largest waterfalls in Europe in terms of both volume and height. These spectacular displays of the power leave one exhilarated, awestruck, and drenched. But it is surely water in its solid form that it the most breath takingly beautiful.
Though many of Iceland’s glaciers have receded during the Holocene interstadial, it still has two large ones. At Longjokul in the West it is possible to go inside a glacier and admire at the different hues of blues on display from cerilian to azure, all directly from natures palette, due ot the air being squeezed out from between the ice crystals by the weight of thousands of tons of ice overhead. On the south of the island another marvel awaits, the sight of icebergs calving. As a glacier becomes unstable, usually because of a warming climate, they discharge small icebergs that make their way to the ocean and melt. The site is one of nature’s most majestic, as huge blocks of ice tinted ozone-blue float on a liquid (one of the many unique properties of water) carrying trillions of dust particles that bear witness to thousands of years of accumulated rainfall.
Whilst fire and earth give Iceland its unique geological features, it is the interplay of air and water that creates the environment for its wildlife. Iceland is located at the boundary between the cold dense water of the Arctic comes down from the North, and the warmer Atlantic water masses that come up from the south, including the Gulf Stream. Where warm meets cold a front is created and nutrient and oxygen rich waters are brought up from the depths, made buoyant because of differences in cold salty ocean masses and lighter warmer water bodies. This polar front is also located at the boundary between two giant atmospheric circulation cells that distribute heat and water from the tropics to the poles through the principle of convection. The so-called Ferrell cell is influenced by the warm south westerlies that blow up from the tropics causing warm moist air to rise at 60 degrees north where Iceland is and then descend as cold dry air at around 30 degrees north where another atmospheric circulation cell. This is the Hadley cell and it is powered by the interplay of ocean and wind at the Equator, and the Polar cell by this same cold interplay at the poles. Squeezed between the two, the Ferrell cell near Iceland is dependent on the other two cells for its power, so it is no surprise that Iceland is (inversely) linked to European climate. Last year, 2018, when Western Europe had one of the hottest spring and summer’s on record, it rained every day in Iceland.
Though inconvenient for us when trying to enjoy the outdoors, for animals and birds this mingling of cold and warm, of dense and fresh, of upwelling and downwelling is the very source of life. Nutrient and oxygen rich waters are brought up from the depths attracting krill and plankton, and in turn many different fish and whale species. In the North, it is possible to see the occasion blue whale, sperm whale or orca, and fin, sai and minke and pilot whales in larger numbers. In the past, vast cod and herring shoals came into Icelandic waters but now due to both overfishing and the climate change affecting the positioning of ocean currents, the shoals re now located further north and smaller in number. For the same reasons, it was also once possible to see the majestic blue whale from the snafels peninsula, easily accessible form Reykjavík, but shifts in ocean currents have moved on this king of the ocean.
The Eyjafjorour fjord where Akureyri is located is also a great and comfortable place to see humpback whales who frequently come into the fjord from the Arctic due to the nutrient rich waters. It is also one of the few places on Earth where experienced divers can explore a hydrothermal vent, usually only found at ocean trenches deep in the ocean. Both of these natural and geological wonders are the result of a retreating glacier that once covered the area.
It wouldn’t be fitting to finish without making reference to Iceland’s volcanoes, large and numerous and by far the most active in Europe. Today harnessed as a source of hydrothermal power, the awesome energy of these volcanoes has influenced history for millennia. When Katla erupted in 1918, world history was made and its continuous outgassing makes it one of the largest volcano sources of CO2 on the planet. The eruption of Hekla in the Bronze Age (around 2345 BC) could have been linked to climate change that resulted in the decline of many thriving Bronze Age civilisations, and the 1159 BC event to plague, famine and pestilence during the reign of King David. [1] In more recent times, the sub glacial eruption of Eyfafjallojokull in 2010 grounded European flights for weeks because of fears of volcanic ash and the more recent rumblings of Grimsvotn, lurking beneath the largest glacier on Iceland, threatened to do the same. We are long overdue for the next major eruption, and there are four main candidates as to which one is next. Katla, Hekla, Grimsvotn or Bardarbunga? Nobody knows for sure which one, but at the time of writing (January 2019), a minor earthquake swarm on the Reykanes ridge could just be indicating deeper activity beneath Hekla. Nobody really knows which one, or when, but that it will happen is not in question. And when it does, it will be big.
[1] See ‘Exodus to Arthur’ by Mike Baille for more information
Earth Wisdom Earth Science 