Esja, in Icelandic called Esjan, which means "the Esja" (), is a mountain situated in the south-west of

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

, about ten kilometres north of Iceland's capital city

Reykjavík Reykjavík ( ; ) is the capital and largest city of Iceland. It is located in southwestern Iceland, on the southern shore of Faxaflói bay. Its latitude is 64°08' N, making it the world's northernmost capital of a sovereign state. With a po ...

. Esja is not a single mountain, but a

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

mountain range, made from

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

and

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

Etymology

The name is likely related to an archaic word, , meaning rock flake or carving stone. In the ''

Kjalnesinga saga Kjalnesinga saga () is one of the sagas of Icelanders (''Islandinga Sögur)''. It is preserved in a parchment manuscripAM 471 4to The work concerns historical ages from the ninth to eleventh centuries, and was composed in the fourteenth century, a ...

'', there is a rich widow among Irish settlers named Esja, but it is likely that the woman's name is derived from the mountain and not vice versa. ''Esja'' can be used as a given name in Iceland.

Formation

Esja was built up at the end of the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

with the beginning of the

Ice Age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

. During the warm periods

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

flowed, and in the cold periods ridges of tuff were built up under the

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

. The western part of the mountain range is the oldest (about 3.2 million years) and the eastern part is the youngest (about 1.8 million years). The movements of the

plate boundaries Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...

cutting diagonally through Iceland are continually pushing the

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

to the west and away from the active volcanic zone.Hvernig myndaðist Esjan?
Vísindavefurinn, 9 December 2008 (in Icelandic)

Intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

s, i.e. large

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

channels coming from the old central volcanoes at

Kjalarnes Kjalarnes () is the least populous district in the municipality of Reykjavík, the capital of Iceland, with a population of around 600 inhabitants. Overview Kjalarnes was an independent municipality, until it joined Reykjavík in 1998. It takes a ...

and Stardalur , found entrances into the strata. The result was a series of large lava fields, one above the other, which the Ice Age glacier ground down. It left only the highest summits, like the mountain ranges of Esja or Akrafjall .

Physical features

The easternmost summits of the mountain range, called Móskarðshnúkar , are of an unusually light colour. An Icelandic writer in the 19th century, so goes the story, hoped to see the sun there after a long period of rain. But when he looked closer, it was only the mountaintops with their colours. In reality, it is the

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

stone, often to be found in Icelandic nature near old (and also active)

central volcano Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as ...

es.

Hiking and climbing

Within easy reach of the capital, Esja is a very popular recreation area for hikers and climbers. The best known hiking paths lead to the summits Þverfellshorn (780 m) and Kerhólakambur (851 m). Þverfellshorn is also easily accessible by public transport. The path is divided into sections, marked with signs along the way. Each sign gives an indication of the difficulty of the path ahead with a grade system ranging from 1 boot (easy) to 3 boots (challenging). At the third sign experienced climbers can choose to climb directly to the peak, instead of following the path which goes off to the right.Esjan - leiðir og saga
Ferlir.is (in Icelandic) After approximately 6.6 kilometers of walking and 597 meters altitude gain is a big rock called Steinn . It is here that most inexperienced climbers choose to go down again, as the path becomes increasingly difficult from there. The highest point, at 914 m, is called Hábunga . From Þverfellshorn, reaching Hábunga requires another three-kilometer trek northeast, across a rocky plateau with no directional signs or clear path. As of August 2011, Hábunga was marked only by a large

cairn A cairn is a man-made pile (or stack) of stones raised for a purpose, usually as a marker or as a burial mound. The word ''cairn'' comes from the gd, càrn (plural ). Cairns have been and are used for a broad variety of purposes. In prehis ...

with a wooden stick at the top. There is danger of avalanches in wintertime. The last fatality was in 2020.Man died in avalanche
Rúv.is

References

{{Authority control Mountains of Iceland Volcanoes of Iceland Pliocene volcanoes Pleistocene volcanoes