ICELANDIC MOUNTAINS AND VOLCANOS

Iceland, the land of ice and fire, is a true paradise. In few places on earth, geology and human history are so closely connected to volcanism as on Iceland. The island owns its existence to a large volcanic hot spot sitting on a mid-oceanic ridge, a unique setting. The plate boundary between the American and Eurasian tectonic plates crosses Iceland from south to North and the spreading process can be directly measured and observed on land.

 

 

Hekla Volcano

Hekla Volcano

HEKLA MOUNTAIN - VOLCANO

1491-m-high Hekla is one of Iceland's most prominent, most known and active volcanoes. It has frequent eruptions that start with an explosive onset producing eruption plumes, then lava fountains and culminate in large lava flows. Most of the volcano's flanks are covered by extensive lava flows from historical eruptions, dating back to 1104 AD.Hekla is located near the southern end of the eastern rift zone. It sits on a rift-transform junction, and has produced basaltic andesites, in contrast to the tholeiitic basalts typical of Icelandic rift zone volcanoes. Hekla's tephras are generally rich in flourine, which is very hazardous to grazing animals.

The elongated shape of the volcano is caused by a 5.5-km-long fissure, Heklugjá, that cuts across the volcano and is often active along its full length during major eruptions. Repeated such eruptions, oblique to most rifting structures in the eastern volcanic zone, have created Hekla's elongated ENE-WSW profile.

Frequent large explosive eruptions during historical times have deposited tephra throughout Iceland and provide important time markers that can be used to date eruptions from other volcanoes in Iceland.

More information available from Wikipedia


EYJAFJALLAJÖKULL - VOLCANO

The name means "glacier" (or more properly here "ice cap") of the Eyjafjöll.

Eyjafjallajökull consists of a volcano completely covered by an ice cap. It is one of the smaller ice caps of Iceland, situated on the southern coast of Iceland, north of Skógar and west of Mýrdalsjökull.  The volcano has erupted relatively frequently since the last glacial period, most recently in 2010.

The mountain, a stratovolcano, stands 1,651 metres (5,417 ft) at its highest point.  The former coastline now consists of sheer cliffs with many waterfalls, of which the best known is Skógafoss. In strong winds, the water of the smaller falls can even be blown up the mountain. The area between the mountain and the present coast is a relatively flat strand, 2 to 5 km (1 to 3 miles) wide, called Eyjafjöll.

In April 2010, almost three thousand small earthquakes were detected near the volcano. The seismic activity continued to increase and from 3–5 March, close to 3,000 earthquakes were measured at the epicenter of the volcano. The eruption is thought to have begun on 20 March 2010.

On 14 April 2010 Eyjafjallajökull resumed erupting after a brief pause, this time from the top crater in the centre of the glacier, causing jökulhlaup (meltwater floods) to rush down the nearby rivers, and requiring 800 people to be evacuated. This eruption was explosive, due to meltwater getting into the volcanic vent. It was estimated to be ten to twenty times larger than the previous one .This second eruption threw volcanic ash several kilometres up in the atmosphere, which led to air travel disruption in northwest Europe for six days from 15 April to 21 April 2010 and also in May 2010,[clarification needed] including the closure of airspace over many parts of Europe. The eruptions also created electrical storms. On 23 May 2010, the London Volcanic Ash Advisory Commission declared the eruption to have stopped, but stated that they were continuing to monitor the volcano. The volcano continued to have several earthquakes daily, with volcanologists watching the volcano closely. As of August 2010, Eyjafjallajökull was considered dormant.

http://archive.boston.com/bigpicture/2010/04/more_from_eyjafjallajokull.html

https://www.discover-the-world.co.uk/destinations/iceland-holidays/about-eyjafjallajokull-volcano

 

 

Eyjafjallajökull / Photo: Reuters, Lucas Jackson

Eyjafjallajökull / Photo: Reuters, Lucas Jackson


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REYKJANES PENINSULA

Reykjanesskagi Peninsula is found on the Southwestern end of the Iceland and close to Reykjavik, the capital city of the country. The peninsula is characterized by active volcanic reactions beneath the surface and large fields of lava with very little vegetation. Hot springs and sulfur springs abound in plenty, especially in the southern half of the peninsula.

Reykjanesskagi Volcano consists of a very big volcano which covers the Reykjanesskagi Peninsula. It is located on the spot where the Mid-Atlantic Ridge is exposed above the sea level. The volcanic system is made of postglacial basaltic crater rows, small shield volcanoes and lava fields. The volcanic system beneath is contagious and is part of the Reykjavik volcanic system. This system is part of the westernmost series of up to four closely paced fissure systems which extends to the Reykjanesskagi Peninsula.

The Reykjanesskagi Peninsula has a lot of applications to the people of Iceland. For instance, there is a geothermal power station located at Svartsengi and near the power station is large swimming pool installed using hot mineralized water from the power station. The pool is also known as the blue lagoon.

More about Reykjanes here: http://www.visitreykjanes.is/en/moya/news


LAKI VOLCANO

Laki, also known as Lakagigar, is a volcanic fissure situated towards the south of Iceland and not very far from Eldgja canyon. It is part of the Grimsvötn volcanic system, lying between the glaciers of Vatnjokull and Myrdalsjokull. The fissures in this area run from the southwest towards the northeast direction.

The Laki volcanic system erupted between 1783 and 1784 for over duration of eight months. The eruption was from the adjoining Grimsvötn volcano and the Laki fissures, where about 14km3 of basalt lava and poisonous compounds of sulfur dioxide and hydrofluoric acid were released. This eruption led to the death of over 50% of Iceland’s livestock population, consequently leading to a famine which claimed a quarter of Iceland’s human population.

But the death of the livestock and the human population were not the only casualties of the eruption and its aftermath. It further led to a significant drop in the global temperatures, owing to the deposition of large quantities of sulfur dioxide in the northern hemisphere. The drop in the global temperatures led to crop failures in Europe and droughts in India. The consequences of the eruption is believed to have claimed a total of six millions lives globally, thus being recorded as the deadliest eruption in the historical times.

Photo credit: www.trekearth.com

Photo credit: www.trekearth.com


Photo credit: volcano.si.edu

Photo credit: volcano.si.edu

KRAFLA VOLCANO

Krafla Volcano is found in the North of Iceland and it is a caldera with a diameter of about ten kilometers with 90km long fissure zones. The highest peak of Krafla reaches about 818m and is 2km in depths. The volcano has experienced a total of 29 eruptions in recorded history.

The Krafla Volcano comprises of the two best known Viti craters in the country. The word “Viti” in Icelandic mean hell and the name originated from the fact that the locals believed that hell existed beneath the erupting volcanoes. The caldera in Krafla is cut by a N-S fissure system which is believed to the be the source of many eruptive and rifting events during the Holocene period.

Inside the crater of Krafla Volcano, there is green lake, the renowned Mývatn Lake which was formed following the eruptions of the older Laxarhraun lava flow from the Ketildyngja shield volcano. This happened about 3800 years ago before present. The present shape of the lake has been constrained by the lava flow from the younger Laxarhraun within the Krafla volcanic system. Also created by the younger Laxarhraun lava flow are pseudocraters which form part of the Mývatn landscape.  

 


KATLA VOLCANO

Katla Volcano is a large volcano found in southern Iceland. With over twenty eruptions documented between 980 and 1918, it remains one of the most active volcanoes in the country, despite the fact that it has not experienced any violent eruptions in close to 98 years. However, Katla has been experiencing small sporadic eruptions, but of lesser magnitudes which have never been able to break the ice cover. The most recent activities of the volcano were recorded in 1955, 1999 and 2011.

Katla has rim diameter covering an area of about 595km2 and the peak reaches about 1512 meters, partially covered by Myrdalsjkull glaciers. The caldera of the volcano has a diameter of ten kilometers, out of which between 200 – 700m is permanently covered with ice. The volcano has a sequence of eruptions between forty and eighty years, and sometime such eruptions are accompanied by large volumes of floods which can be compared to the combined average discharges of the Nile, Mississippi, Amazon and Yangtze rivers.

The last major eruption of Katla was recorded in October 1918 which lasted for a period of 24 days. The eruption ended up extending the southern coast with over 5,000 m and its current dormancy is among the longest ever experienced in the history of volcanoes in Iceland.

 

Photo credit: survincity.com

Photo credit: survincity.com


Photo credit: volcanocafe.wordpress.com

SURTSEY VOLCANO

The Surtsey eruption took place between 1963 and 1967 and it went down the books of history as the longest eruption ever witnessed in Iceland. It is believed that the eruptions had started a few days at about 130m deep inside the sea before it finally reached the surface. The explosion of the Surtsey was characterized by various phases in the beginning and due to the faster cooling that happened in the sea, the hot magma that formed quickly turned into tephra or volcanic ash.

So rapid was the production of the volcanic ash that after just one day of the explosion, an island had already been formed. When the explosion finally died out, the new island was at an elevation of 174m above the sea level and over 300 above the sea floor from where the explosion started.

The original size of the ridge is not well known, but when it was measured for the first time in 1616, it was found to be 100 meters from the east to the west and 700 meters from the north to the south. By the year 1903, half of that size had already diminished and by 2001, what was remaining was a mere 90m2, at an elevation of about 8 meters above the sea level.

When the eruptions finally stopped in June 1967, the volcano had been active for close to four years, creating an island of a total area of 2.7km2 and ejecting debris of about 1.1km3 of volcanic materials. In many aspects, the formation of Surtsey volcano can be compared to the eruptions that formed the Palagonite Mountains during the Ice Age in Iceland.

 

 


HENGILL VOLCANO

The Hengill Volcano is located in the Southwest of Iceland and it comprises of a series of NE – SW trending fissure vents, small shield volcanoes, and crater rows covering a total area of 100km2. Though the last eruption was recorded over 2000 years ago, Hengill Volcano is still active, as evidenced by the fumaroles and the plethora of hot water springs.

Hengill Volcano is on the easternmost section of a series of four closed placed basaltic fissures. The system goes diagonally through the Reykjanes peninsula, passing through the point where Reykjanes peninsula, the south Iceland seismic zone and the western volcanic zones come together. Its geographic composition makes it active, even though the last known eruption is believed to have happened thousands of years ago.

The volcano has a strategic importance to the country, since it is the main source of energy serving the southern parts of the country. Other than producing power, the mountainous regions and the hot springs also attract a lot of adventure lovers who come to hike and enjoy the natural sceneries.

Photo credit: volcano.si.edu

Photo credit: volcano.si.edu


Photo credit: memim.com

Photo credit: memim.com

ASKJA VOLCANO

Askja is a sunken crater or caldera found in the remote parts of the Central Highlands in Iceland. Askja is at the center of a volcanic system comprising of many fissures found around the Dyngjufjoil Mountains. The formation of the mountains was due to an eruption which took place under an Ice Age glacier cap. The formation of Askja, in particular, took place at the end of the Ice Age following a major ash eruption which displaced the roof of the magma chamber located at the center the central volcano. After the eruption, a deep circular depression was formed and with time, the depression began to fill up with lava which came for subsequent eruptions.

The rim of Askja stands at between 1300 – 1500 meters above the sea level while the bottom is at 1100 meters below the sea level. The name Askja is used in Iceland to refer to the formation of many similar volcanoes found in other location throughout the country. The last activity of in Askja was an eruption that occurred in 1961 and even though in 2011, an increase in seismic activities was reported, there has never been an eruption since then.  

 


ELDFELL VOLCANO - VESTMANNAEYJAR

Eldfell is located in the island of Heimaey in Iceland. It is a composite volcanic cone rising for slightly over 200 meters above the sea level. The formation of the cone was due to a volcanic eruption which started on the east side of Heimaey and advanced towards the west of the islands in 1973.

The eruption of Eldfell came without any warning and so serious it was that it almost led to the permanent evacuation of the island. The ash from the eruptions scattered on most parts of the island, destroying over 400 homes and the lava flow almost led to the closure of the harbor, which is Island’s main source of income. To stop the lava flow from causing the closure of the harbor, sea water was pumped onto it to cool it down and make it to solidify to stop further flow.

Following the eruptions, the heat from the cooling lava was used to generate electricity and provide hot water to homes. Some of the volcanic materials from the eruption were also used in extending the runway in Island’s airport and also as landfill which was then used to construct up to 200 homes.

Photo credit: www.metafilter.com

Photo credit: www.metafilter.com


Photo credit: http://www.vatnajokulsthjodgardur.is/english

Photo credit: http://www.vatnajokulsthjodgardur.is/english

ELDGJA VOLCANO

Eldgjá is a volcano and at the same time a canyon in Iceland. It is considered as the largest volcanic canyon in the world, having a length of 40km, a width of 600 meters and running up to 270m deep. Eldgjá was discovered in 1893 and its first documented eruption occurred in 934, which led to the largest flood basalt ever recorded in history back then. During this explosion, the lava covered an area of about 800km2 and about 18km3 of lava was released.

Eldgjá canyon has a beautiful water fall situated on River Ófæruá. It is a two split waterfall, with magnificent sceneries all around it. Up until 1993, the waterfall used to have a natural bridge on the lower parts, but the bridge was covered by water and ceased to exist due to excessive melting of the ice, which increase the volume of the water in the river. Presently, the northern parts of the canyon, including the Ófærufoss and the neighboring regions have been designated as part of the Vatnajökull National Park.

More info here: http://www.vatnajokulsthjodgardur.is/english/destinations/eldgja-langisjor/

 

 


GRIMSVOTN VOLCANO

Grimsvötn Volcano is considered as one of the most frequently active volcanoes in Iceland. This can be attributed by the fact that its location is at the center of an active NE rift zone in the country. A huge part of the volcano is hidden under the Vatnajökull glacier, the largest glacier in Europe.

Grimsvötn Volcano has a caldera at an elevation of about 1725m above the sea level and only the southern rim of the caldera is exposed. Inside the caldera, there is a lake of liquid water, believed to be warmed by the energy originating from the volcano. On the surface, the lake is covered by an ice glacier, but during increased activity from the volcano, the pressure emanating from the lake become so powerful that the ice glacier on the surface is poured out on the southern side of the caldera leading to devastating floods known as jökulhlaups.

The structure of Grimsvötn Volcano is dominated by NE- SW trending fissures, which also correspond to the rift zone. Eruptions arising from the fissures can go beyond the glacier, as was the case of the Laki fissure eruptions which took place in 1783. The latest known eruption of Grimsvötn Volcano was in May 2011, which began with 12km high plumes followed by multiple earthquakes. The eruption took place for about five days and it resulted in the cancellation of close to 900 flights across Europe.

 

Photo credit: www.theatlantic.com

Photo credit: www.theatlantic.com


Photo credit: www.lhg.is

Photo credit: www.lhg.is

KOLBEINSEY RIDGE

Kolbeinsey Ridge is a small isle stretching about 65 miles off the northern coast of Iceland. The ridge is in the northernmost part of Iceland and it lies towards the north of the Arctic Circle. Being a basalt landform without any vegetation, Kolbeinsey Ridge has been subjected to rapid wave erosion, making it susceptible to extinction in the near future, with some predicting that to happen in 2020.

The original size of the ridge is not well known, but when it was measured for the first time in 1616, it was found to be 100 meters from the east to the west and 700 meters from the north to the south. By the year 1903, half of that size had already diminished and by 2001, what was remaining was a mere 90m2, at an elevation of about 8 meters above the sea level.

It is believed that the ridge formed due to a submarine eruption reported in 1372 near the northwest of Grimsey. Kolbeinsey Island is the only portion of the Mid-Atlantic ridge that is still visible on the surface. The island is believed to have formed during the late Holocene period, believed to have taken place about 11,800 radiocarbon years ago.