Terrain shapes and bedrock
According to COUNTRYAAH, Iceland is a young lava plateau with no less than 200–300 volcanoes, of which about 30 are active. Geologically, the island differs radically from the closest land areas of Greenland, Scotland and Norway. The island’s volcanic character has its explanation in that it is a part of the Atlantic central ridge rising above the sea surface. The reason why a large island was formed here is that the ridge lies straight over a hot spot, which has resulted in an abnormally large outflow of magma.
The rocks in Iceland are mostly volcanic basalts of different ages. The oldest are plateau basal salts from the neogene in the west and northeast (14-18 million years old). During the recent ice age, volcanic eruptions occurred partly down the ice sheet, which caused fragmentation of the lava. The solutes, however, were converted to a hard, hard rock, so-called hyaloclastitis. Volcanism in post-glacial times is concentrated in the rift, or the active central zone of the Atlantic Central Ridge, which covers about 30% of the country’s surface. The rift has a western and an eastern branch, which in northern Iceland merge into one. Here, primarily light-flowing lavor is produced, and long crater chains are built up. However, around volcano centers there are also Andesites, Dacites andryolites in the form of viscous liquor and tea.
The eastern zone includes: Vestmannaeyjar with Surtsey, formed in 1963-67, and Heimaey where the volcano Eldfell erupted in 1973.
Along this zone are most of Iceland’s active volcanoes. Among these, Katla is marked during Mýrdalsjökull and Hekla with about twenty outbreaks each in historical time, furthermore Laki, Tröllagígar, Grímsvötn, Kverkfjöll and Askja as well as Krafla with nine outbreaks in 1975–84. A number of outbreaks have been documented in the western zone, e.g. at the formation of Eldeyjar 1211, Trölladyngja and Eldborgir. At the Langjökull Glacier, this zone turns east and joins the east. To the east of the actual spread zone lies Öræfajökull, a volcano covered by southern Vatnajökull ice masses and with Iceland’s highest peak, Hvannadalshnúkur, 2,119 m above sea level.
Other expressions of Iceland’s volcanically active bedrock are solar fathoms with outflow of steam and hot water in springs. Some of the sources are intermittent, ie. Water is thrown out at regular intervals, and is called geysers.
Glaciers cover 11% of the island’s surface. The largest is Vatnajökull, 8 400 km2, then Hofsjökull, Langjökull and Mýrdalsjökull.
The plateau glaciers descend into valley glaciers and in front of these, sandy fields are built up. A wide network of river arms extends across these vast sandy areas, which has created great difficulties for accessibility and for road and bridge construction.
Iceland is dominated by a plateau and fjord landscape with an average height of 500 m above sea level. Only one quarter of the landscape is lower than 200 m above sea level. The relief is characteristic of a young topography with mostly sharp-cut and spiny shapes, which are evident because no forest and often no vegetation obscures the view. Frost weathering is very effective because of the bedrock cracks and the constant shifts around the freezing point. Through the continual new formation of bedrock along the rift, central Iceland is lowered and the plateau basalts therefore tilt inward. The glacial erosion of the ice age has deepened the original river valleys and sometimes faults have contributed, e.g. i Skagafjörður. The wave erosion has created a continental shelf and wide beach plan as well as impressive coastal cliffs, especially on the south and west coasts. The lava beds stored on top of each other and the pillar gap of the basalt are conspicuous landscape elements. In the interior, active volcanism has created a more open topography with clear linear features in the form of fracture zones, valleys, ridge ridges and crater rows as well as larger volcanoes andplateau mountain.
The rivers in Iceland are short but have relatively high flow due to high rainfall. The farthest is Thjórsá. The glacial rivers, one of the three river types in Iceland, are heavily sediment-laden and often meander over large sandy areas. Another type of rivers, migratory rivers (clear water rivers), dewatering the old basalt areas, has a large number of small falls and strongly varying water flow. A third river type, riverine lakes, dewateres the post-glacial basalt areas, has a constant water flow and temperature, and clear water. The largest waterfall is Dettifoss (48 m) in Jökulsá á Fjöllum, and the most visited is Gullfoss (about 50 m in two ledges). Numerous lakes exist, some of tectonic origin, such as Thingvallavatn, others are dammed by lava flows, e.g. Myvatn. Sudden drops of ice lakes, so-called glacier races, can be disastrous. Grímsvötn in Vatnajökull is the most famous; a glacier can reach a water flow of 50,000 m 3 per second here.
Iceland’s location mainly south of the Arctic Circle results in a humid climate that borders between warm and cold temperatures (see Climate: Earth’s Climate). According to BRIDGAT, the climate is mitigated by the surrounding large sea areas and by the North Atlantic current with its western branch, the Irminger stream, which extends near the south, west and parts of the north coast. However, from the north comes a branch of the cold East Greenlandic current, which can bring drift ice to the north and east coasts. The polar front, the boundary between icy air and warm air from the south, is often located across the island, which is why many migrating low pressures cause windy and humid weather, especially during the winter months.
The annual average temperature is at most about 5 °C in the southern and southwestern coastal regions, and about –9 °C in the coldest regions in the northwestern part of Vatnajökull. The summers are cool with an average July temperature of around 11 °C in the southernmost parts and in some valley regions in the north. Most of Iceland therefore belongs to the Arctic climate group according to Köppen’s climate classification. Winters are mild and rainy with an average January temperature of 0 °C in the south and −15 °C above the inland glaciers. However, the temperature deviations can be large: if the weather fronts pass south of the island, cold air is brought down from the polar area, but if they migrate north, warm air is introduced over Iceland. The absolute heat record is 30.5 °C and the cold record is -39.7 °C. Föhnvindar under favorable conditions, high temperatures also lead to wintertime, and the heat record in February is 20.5 °C, warmer than in any other country in the Nordic countries.
The rainfall can amount to about 2,000 mm per year in the south, although the southern slopes of the glaciers can get over 4,000 mm per year. In the north, the precipitation is between 400 and 1000 mm per year. In the northwest, snow falls for about 100 days, in the south below 40.
Heavy dust storms can form when hard, dry winds from the glaciers spread down over the surrounding dry sandy fields and stir up sand and dust. Particularly frequent are dust storms north of Vatnajökull in the summer and autumn. Thunderstorms are rare in Iceland, but can occur when humid air masses are carried north across the southern coastal regions in late summer or in ash clouds from active volcanoes.
Plant-and animal life
Iceland’s flora and fauna are relatively young and poor in species. Immigration of plants and animals took place only after the latest icing and the low number of species is due to Iceland’s isolated and northern location. The species is northwestern European with few purely arctic features and no endemic species.
Nowadays, a quarter of Iceland is covered by vegetation, compared to twice the size of the first settlements in Iceland in the 8th century. The early settlers used the low-grown birch forests (then 30 percent of the island’s area) as fuel and for cattle grazing. Human intervention has drastically reduced the forests (now 1 percent of the island’s surface) and has thus initiated extensive erosion.
Iceland’s central highlands lack natural vegetation for natural reasons, with the exception of some marshes (where, among other things, Spetsberg Goose hedges) and some drier lands with species such as mountain sip, purple clay and mountain meadow. In the lowlands, grass and rice species with ropes, redwing, crowberry, heather, dwarf birch and low-growing species prevail in the genus Know. The wetlands are dominated by starches.
Large areas of Iceland are completely vegetation-free or covered by lava. New lava is first invaded by lichen and dragonfly, then by rice and bushes and finally, if development is allowed to continue, by glass birch.
High-herb vegetation is found in places that have favorable microclimate or are protected from sheep grazing. Locations with concentrated geothermal heat (hot springs) have special flora and fauna, such as flies of the genus Scatella.
The bird fauna comprises about 75 breeding species (another approximately 300 species have been observed); most are seabirds attached to the bird mountains (for example Vestmannaeyjar), ducks and waders. Common puffins and other alcs are common, as are storm birds and various gulls. Iceland has several colonies with seabirds (among others on the island of Eldey, where the last known pair of the now extinct turtle was killed in 1844) and large lab.
Common waders are heather whiskers, small spawls and small -beaked snake snakes (broad-beaked snake nest with few pairs), and of birds of prey there are hunting falcon, rock falcon, sea eagle (few) and earth owl. The number of species of seals is small, with meadow spruce and red-wing traits being the most common. Iceland has an endemic subspecies of bait.
Of terrestrial mammals, mountain foxes are native, while mink, reindeer and a few species of small rodents have come through human care. Frogs and crawfish are completely missing. The insects comprise about 1,250 species, among which, for example, day butterflies, mosquitoes and ants are missing. Rivers and lakes are often rich in gnats and midges, and therefore also of carnivorous salmonids (salmon, trout and char). The waters around Iceland contain more than 150 marine fish species, and the fauna of the coastal bottoms and beaches is rich.
Lake Mývatn houses one of the world’s largest concentrations of nesting ducks (13 species) with, among other things, the island snake and stream (the latter only in flowing water). These two species together with Islam form the North American feature of the bird fauna; none of them breed in the rest of Europe.
The Vestmannaeyjar archipelago, an archipelago of 15 islands south of the mainland, has Iceland’s largest bird mountain. Most commonly lunnefågel (about 1 million pairs) followed by Leach’s Storm Petrel (167000-225000 pair), storm cool (50,000 to 100,000 pair), Fulmar (65 000 pairs), Guillemot (60 000 pairs) and kittiwakes (32 000 pairs). In order to extinguish the one-sided diet of fish, the population collects eggs of storm birds and alcoves, young soles and catch adult adult puffins every year.
Other famous birdwatchers in Iceland are Eldey, Skoruvik-Skalabjarg, Grimsey, Skrúður, Hornbjarg and Latrabjarg, with the country’s largest colony of spetsberg grissla (80,000–164,000 pairs). At Thjorsarver south of Hofsjökull Glacier in central Iceland, with marshes, lakes and streams scattered on the tundra, there is the largest concentration of spetsberg goose with 6,000 to 10,000 nesting pairs.
The thousands of islands and tidal areas at Breiðafjörður on the western part of the island house more than 40,000 pairs of eider, large cormorant, top cormorant, white-tailed and sea-tailed, and in spring and autumn large flocks of barbed goose and shorebirds gather on their way between the nesting areas in Greenland and wintering areas in winter.
More than 20 different species of whales and dolphins live regularly in the waters around Iceland. Most common are minke whales, porpoises vitnosdelfin and humpback whales, but killer whales, northern bottlenose whale, Atlantic white-sided dolphin, pilot whale, fin whale, blue whale and the sperm whale is rare. More than 100,000 tourists visit Iceland every year for whale watching.
Six different species of seals occur, especially in northern Iceland where seal sighting is offered on the Vatnsnes Peninsula. In addition to the harbor seals and gray seals, who are resident, visited Iceland every year by the harp, blåssäl, ringed seals and bearded (rare).
Nature conservation in Iceland consists of national parks, national parks, nature reserves and monuments and covers about 15% of the country’s area. Around 80 nature-protected areas can be found in Iceland (2012).
National parks are set up on state land to protect unique landscapes, flora and fauna, or places of special historical significance. Iceland’s three national parks are Þingvellir, Snaefellsjökull and Vatnajökull (see table). The largest protected area in Iceland is Vatnajökull, which with an area of 13,000 km2 is the largest national park in Europe. The area includes Vatnajökull glacier, Skaftafell and Jökulsárgljúfur. Thingvellir is one of Iceland’s most popular tourist destinations with a dramatic landscape on the Atlantic Central Ridge, the dispersal zone between the North American and Eurasian tectonic plates. Lake Thingvallavatn, Iceland’s largest, is a unique biotope thanks to mineral supply from volcanic activity. Snaefellsjökull National Park includes the stratovolcano of the same name and a glacier in the western part of the Snaefellsnes peninsula.
Nature reserves are protected areas for sensitive nature, flora and fauna, with limited visitor and exploitation rights. Monuments include unique and beautiful natural phenomena of high conservation value or scientific interest. fossil and mineral deposits, geological formations, waterfalls, volcanoes and hot springs. Landsparker enjoys less strict nature protection, is established on local initiative and is intended for recreation.