Esja (; often Esjan , with the feminine definite article) is a mountain situated in the south-west of

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

, about ten kilometres north of Iceland's capital city

Reykjavík Reykjavík is the Capital city, capital and largest city in Iceland. It is located in southwestern Iceland on the southern shore of Faxaflói, the Faxaflói Bay. With a latitude of 64°08′ N, the city is List of northernmost items, the worl ...

. Esja is not a single mountain, but a

volcanic A volcano is commonly defined as a vent or fissure 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 fo ...

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. Reykjavik Esja

Etymology

The name is likely related to an archaic word, , meaning rock flake or carving stone. In the '' Kjalnesinga saga'', 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 ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

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 g ...

. 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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

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

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

. 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 cutting diagonally through Iceland are continually pushing the

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

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 (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

channels coming from the old central volcanoes at Kjalarnes 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 (geology), texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained matri ...

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

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 June 2024, Hábunga was marked only by a large

cairn A cairn is a human-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 (plural ). Cairns have been and are used for a broad variety of purposes. In prehistory, t ...

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