Geology of Iceland

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Iceland Mid-Atlantic Ridge map.svg
Map of hotspots. Iceland is number 14. Hotspots.jpg
Map of hotspots. Iceland is number 14.

The geology of Iceland is unique and of particular interest to geologists. Iceland lies on the divergent boundary between the Eurasian plate and the North American plate. It also lies above a hotspot, the Iceland plume. The plume is believed to have caused the formation of Iceland itself, the island first appearing over the ocean surface about 16 to 18 million years ago. [1] [2] The result is an island characterized by repeated volcanism and geothermal phenomena such as geysers.

Contents

The eruption of Laki in 1783 caused much devastation and loss of life, leading to a famine that killed about 25% of the island's population [3] and resulted in a drop in global temperatures, as sulfur dioxide was spewed into the Northern Hemisphere. This caused crop failures in Europe and may have caused droughts in India. The eruption has been estimated to have killed over six million people globally. [4]

Between 1963 and 1967, the new island of Surtsey was created off the southwest coast by a volcanic eruption.

Geologic history

The opening of the North Atlantic and the origin of Iceland

Iceland is located above the Mid-Atlantic Ridge. Some scientists believe the hotspot beneath Iceland could have contributed to the rifting of the supercontinent Pangaea and the subsequent formation of the North Atlantic Ocean. Igneous rocks which arose from this hotspot have been found on both sides of the Mid-Atlantic Ridge, which originated 57–53 million years ago ("Ma"), around the time North America and Eurasia separated and sea floor spreading began in the Northeast Atlantic. [5] Geologists can determine plate motion relative to the Icelandic hotspot by examining igneous rocks throughout the Northern Atlantic region. This is possible because certain rocks attributable to hotspot volcanism can be interpreted as volcanic traces left by the Iceland hotspot. [5] By assuming that the hotspot is stationary, geologists use what is called the "hotspot frame of reference" to gather plate motion estimates and to create maps of plate movement on the surface of the Earth relative to a stationary hotspot.

Most researchers of plate motion agree that the Iceland hotspot was probably located beneath Greenland for a period of time. As the North Atlantic Ocean continued to spread apart, Greenland was located to the southeast of the Iceland hotspot and likely moved over it 70–40 Ma. [6] Some research using new plate motion data gathered from hotspot reference frames from around the world suggests that the Iceland hotspot's path differs from that estimated from older investigations. Many older rocks (dated 75–70 Ma) located throughout the area to the west are not only located near hypothesized Iceland hotspot paths but are also attributable to hotspot volcanism. This implies that the Iceland hotspot may be much older than the earliest rifting of what is now the northernmost Northeast Atlantic. If this is true, then much of the rifting in the North Atlantic was likely caused by thinning and bulging of the crust as opposed to the more direct influence of the mantle plume which sustains the Iceland hotspot. [5]

In other scientific work on the path of the Iceland hotspot, no such westward track toward Canada (where the aforementioned older igneous rocks exist) can be detected, which implies that the older igneous rocks found in the Northern Atlantic may not have originated from the hotspot. [6] [7] Although the exact path of the Iceland hotspot is debated, a preponderance of geophysical evidence, such as the geothermal heat flux over Greenland, shows that the hotspot likely moved below Greenland around 80–50 Ma. [7]

Around 60–50 Ma, when the hotspot was located near the eastern coast of Greenland and the Mid-Atlantic Ridge, volcanism, perhaps generated by the Iceland hotspot, connected the Eurasian and North American continents and formed a land bridge between the continents while they spread apart. This feature is known as the Greenland Scotland Transverse Ridge, and it now lies below sea level. [8] About 36 Ma, the Iceland hotspot was fully in contact with the oceanic crust and possibly fed segments of the Mid-Atlantic Ridge which continued to form the oldest rocks located directly to the east and west of modern-day Iceland. The oldest sub-aerial rocks in modern-day Iceland are from 16.5 Ma. [5] [8]

Although most scientists believe Iceland is both in contact with a mantle plume, and being actively split apart by the Mid-Atlantic Ridge, some other seismological and geophysical evidence calls the previously discussed mantle plume/hotspot assumption into question. Some geologists believe there is not enough definitive evidence to suggest a mantle plume exists beneath Iceland because sea floor heat flow through the lithosphere surrounding Iceland does not deviate from normal oceanic lithosphere heat flow that is uninfluenced by a plume. [9] This cold crust hypothesis directly opposes the idea that Iceland is located above a hot mantle plume. Additional evidence indicates that seismic waves created under Iceland do not behave as expected based on other seismic surveys near hypothesized mantle plumes. [10] As it is one of the only places where sea floor spreading can be observed on land, and where there is evidence for a mantle plume, the geological history of Iceland will likely remain a popular area of research.

Glaciations

Holocene changes and volcanism

Rock types

Volcanic deposits

Intrusive rocks

Sedimentary deposits

One of the rare examples of sedimentary rocks in Iceland is the sequence of marine and non-marine sediments present on the Tjörnes Peninsula in northern Iceland. These Pliocene and late Pleistocene deposits are composed of silt and sandstones, with fossils preserved in the lower layers. [11] The primary fossil types found in the Tjörnes beds are marine mollusk shells and plant remains (lignite).

Active tectonics

Ogmundarhraun lava field, Road 427, Reykjanes Peninsula View of Ogmundarhraun lava field in Iceland from Road 427 2.jpg
Ögmundarhraun lava field, Road 427, Reykjanes Peninsula

The tectonic structure of Iceland is characterized by various seismically and volcanically active centers. Iceland is bordered to the south by the Reykjanes Ridge segment of the Mid-Atlantic Ridge and to the north by the Kolbeinsey Ridge. Rifting in the southern part of Iceland is focused in two main parallel rift zones. The Reykjanes Peninsula Rift in SW Iceland is the landward continuation of the Reykjanes Ridge that connects to the Western Volcanic Zone (WVZ). The more active Eastern Volcanic Zone (EVZ) represents a rift jump, although it is unclear how the eastward propagation of the main rifting activity has occurred. [12] The offset between the WVZ and the EVZ is accommodated by the South Iceland Seismic Zone, an area characterized by high earthquake activity. The EVZ transitions northward into the Northern Volcanic Zone (NVZ), which contains Krafla volcano. The NVZ is connected to the Kolbeinsey Ridge by the Tjörnes Fracture Zone, another major centre of seismicity and deformation.

Associated with the active volcanism in the rift zones are high-temperature geothermal fields. These are driven by magma intrusion and are associated with temperatures around 200–300 °C (392–572 °F) at more than 2 km (1.2 mi) depth while beyond the rift zones, particularly on the North American Plate are found low-temperature geothermal fields related to local disturbances in the general heat flow from the mantle which have temperatures lower than 150 °C (302 °F) at 2 km (1.2 mi) depth. [13]

There is continuing active volcanism and a recent example is the volcanic and earthquake activity occurring in the Reykjanes Peninsula from 2020 onwards, after nearly 800 years of inactivity. After the eruption of the Fagradalsfjall volcano on 19 March 2021, National Geographic's experts predicted that this "may mark the start of decades of volcanic activity". [14] There was a fissure eruption adjacent to the summit of Litli-Hrútur in July 2023, [15] followed in October 2023 with earthquake unrest that lead to the evacuation of the town of Grindavik. Then a new fissure eruption happened in the Eldvörp–Svartsengi area on 18 December 2023, with activity ongoing in 2024. [16]

Modern glaciers

The history of glaciation on Iceland began 3.3 million years ago, marking a dramatic change in environmental conditions. [17] Glaciers cover about 11% of Iceland; easily the largest of these is Vatnajökull. Icelandic glaciers have generally been retreating over the past 100 years. Vatnajökull has been described as one of the more sensitive glaciers to climate change [18] and has lost as much as 10% of its volume. [19]

As many glaciers overlie active volcanoes, subglacial eruptions can pose hazards due to sudden floods produced by glacial meltwater, known as jökulhlaup. Another subglacial volcanic hazard is the phreatomagmatic eruption. In the case of Iceland, this type of eruption is the cause of massive plumes of volcanic ash that migrate to Europe and disrupt air traffic. [20] Historically these explosive eruptions have had other impacts on human civilization as well, including acid rain and significant changes in weather patterns. [18] Grímsvötn – a major sub-glacial volcano located beneath the Vatnajökull ice cap – is prone to this type of eruption. [21]

Icelandic Surge-type Glaciers

All of Iceland's ice capped volcanic plateaus have unique surge-type glaciers, some of the best studied are Brúarjökull, Eyjabakkajökull and Múlajökull. Surge-type glaciers account for less than 1% of glaciers worldwide and are relegated to a narrow climate band with cold marine low arctic conditions. These glaciers exhibit a dual phase development: 1. long periods of quiescence with small scale seasonal advance and retreat, 2. sudden and rapid advancement lasting several months to years. One of the largest glacial surges in recorded history occurred in 1963-64 when the Brúarjökull glacier advanced 9 km in a period of approximately 3 months. Glacial ice advanced 120 meters per day moving 34 million cubic meters of ice and rock. [22]

Researchers are working to understand the glacial stability and threshold behaviors of these glacial surge events. While mechanisms are still poorly understood, surge frequency could be related to climate cycles, basal hydrology, volcanic eruptions and jökulhlaups. [22] Work has been done to understand the glaciotectonic interactions between the base of glacial ice and subglacial sediment that allows for such rapid motion. A model proposed in 2006 suggests that due to high pore fluid pressures in fine grained basal sediments, surge glaciers like Brúarjökull decouple beneath subglacial sediments along a strong stratigraphic contrast (subglacial sediment vs impermeable basalt bedrock). Connecting these tectonic models with produced moraine products has proved useful in understanding the dynamics of these complex glacial systems. [23]

Plate Movement and Deformation

Global plate motion models have determined that Iceland is rifting at a rate of approximately 1.8–1.9 cm/year (0.71–0.75 in/year). [24] Several processes contribute to the movement and deformation of the Icelandic landmass, such as the spreading plate boundary, active volcanism, seismic activity, and glacial activity. With time, it's believed that the result of these forces will be to create new plate boundaries, with the potential for the formation of new micro-tectonic plates. [17]

The rate of plate rifting, or spreading, varies across the island, but generally is the greatest near zones of more active volcanism. Accordingly, volcanism on Iceland can be related to the amount of crustal spreading in each region. These distinctions reveal that regions of older, less active volcanism are split by regions of younger activity, revealing the location and trend of the active rifting zones. In Iceland there is a high rate of seismicity, with most earthquakes being recorded at or near these zones, correlated with active volcanoes and motion of the spreading boundary, often expressed as system of transform faults. [17] Generally the most significant earthquakes are in the transform zones of the South Iceland Seismic Zone and Tjörnes Fracture Zone, and at central volcanoes undergoing volcanic unrest. [17]

Glaciation on Iceland has a significant impact on erosional patterns, the formation of volcanic landforms, and the movement of the crust. Glacial isostatic adjustment as a response to the retreat of glacial systems since the 1890's shows a horizontal displacement of a few millimeters per year. Vertical rebound is much greater, with thinning of glaciers resulting in approximately 30 mm/yr of vertical motion. Extended periods of monitoring suggest that the rate of vertical motion of Iceland is increasing, as glaciers continue to be depleted. [17]

Human impact and natural catastrophes

Deforestation

Deforestation of Iceland has been a result of human impact and the climate. [25] Since the island’s settlement in the 7th century, the native forests and woodlands have been cut down for fuel and for timber. [25] Upon settlement, it had a rich environment, but it was fragile. After consistent logging and resource exploitation, only about 1.9% of the country is a forest or woodland, mostly made up of small birch and willows. [25] [26] There have been projects to improve the nation's woodland through the Icelandic Forestry Service. [25] [26]

Soil erosion

Soil erosion is a major environmental degradation issue for Iceland with 39% of the country's land being categorized as having extensive soil erosion. [27] The country’s woodlands and forests have been exploited for fuel and timber and as settlements grew, livestock populations increased and agriculture expanded. [26] Many natural and anthropogenic causes have made Iceland a scarce landscape made up of grasses, moss, and short, thin trees, such as pine and birch. [26] Its lack of vegetation cover has left the soil more vulnerable to weathering and natural catastrophe events, such as volcanic activity and landslides. [27] [25] Iceland’s cold climate slows plant growth, leaving the soil susceptible to the impact of strong winds. [25] Soil erosion, and land degradation in general, decreases biodiversity and the health of the surrounding ecosystems. [25]

The government of Iceland and its people have undertaken many soil restoration projects. They created the Soil Conservation Service of Iceland (SCS) in 1909 which works on ecosystem restoration projects. [27] [25] In 2007, they organized the Hekluskógar project where local landowners and farmers were encouraged to plant native birch and willows on their lands. [28] By 2010 over 2.3 million seedlings were planted in small inlets around the country. [28]

Overgrazing

Soil erosion rates are also increased by overgrazing. Sheep are one of the primary livestock of Iceland and have been there for centuries. [25] During this time, the sheep have grazed on the native vegetation and began to exhaust the local resources as the sheep populations grew. [25] A lack of preventative policy led to overgrazing in multiple areas across the country. The persistent issue of land degradation caused by overgrazing and land exploitation remains a pressing concern. [25]

Other

See also

Related Research Articles

<span class="mw-page-title-main">Geography of Iceland</span> Geographical features of Iceland

Iceland is an island country at the confluence of the North Atlantic and Arctic oceans, east of Greenland and immediately south of the Arctic Circle, atop the constructive boundary of the northern Mid-Atlantic Ridge. The island country is the world's 18th largest in area and one of the most sparsely populated. It is the westernmost European country when not including Greenland and has more land covered by glaciers than continental Europe. Its total size is 103,125 km2 (39,817 sq mi) and possesses an exclusive economic zone of 751,345 km2 (290,096 sq mi).

<span class="mw-page-title-main">Volcanism of Iceland</span>

Iceland experiences frequent volcanic activity, due to its location both on the Mid-Atlantic Ridge, a divergent tectonic plate boundary, and over a hot spot. Nearly thirty volcanoes are known to have erupted in the Holocene epoch; these include Eldgjá, source of the largest lava eruption in human history.

<span class="mw-page-title-main">Grímsvötn</span> Volcano in Iceland

Grímsvötn is an active volcano with a fissure system located in Vatnajökull National Park, Iceland. The volcano itself is completely subglacial and located under the northwestern side of the Vatnajökull ice cap. The subglacial caldera is at 64°25′N17°20′W, at an elevation of 1,725 m (5,659 ft). Beneath the caldera is the magma chamber of the Grímsvötn volcano.

Viedma is a subglacial volcano whose existence is questionable. It is supposedly located below the ice of the Southern Patagonian Ice Field, an area disputed between Argentina and Chile. The 1988 eruption deposited ash and pumice on the ice field and produced a mudflow that reached Viedma Lake. The exact position of the edifice is unclear, both owing to the ice cover and because the candidate position, the "Viedma Nunatak", does not clearly appear to be of volcanic nature.

<span class="mw-page-title-main">Iceland hotspot</span> Hotspot partly responsible for volcanic activity forming the Iceland Plateau and island

The Iceland hotspot is a hotspot which is partly responsible for the high volcanic activity which has formed the Iceland Plateau and the island of Iceland.

<span class="mw-page-title-main">Southern Peninsula (Iceland)</span> Region of Iceland

Southern Peninsula is an administrative unit and part of Reykjanesskagi, or Reykjanes Peninsula, a region in southwest Iceland. It was named after Reykjanes, the southwestern tip of Reykjanesskagi.

<span class="mw-page-title-main">Volcanism of Canada</span> Volcanic activity in Canada

Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes, and maars, along with less common volcanic forms such as tuyas and subglacial mounds.

The Anahim hotspot is a hypothesized hotspot in the Central Interior of British Columbia, Canada. It has been proposed as the candidate source for volcanism in the Anahim Volcanic Belt, a 300 kilometres long chain of volcanoes and other magmatic features that have undergone erosion. This chain extends from the community of Bella Bella in the west to near the small city of Quesnel in the east. While most volcanoes are created by geological activity at tectonic plate boundaries, the Anahim hotspot is located hundreds of kilometres away from the nearest plate boundary.

<span class="mw-page-title-main">Volcanism of Northern Canada</span> History of volcanic activity in Northern Canada

Volcanism of Northern Canada has produced hundreds of volcanic areas and extensive lava formations across Northern Canada. The region's different volcano and lava types originate from different tectonic settings and types of volcanic eruptions, ranging from passive lava eruptions to violent explosive eruptions. Northern Canada has a record of very large volumes of magmatic rock called large igneous provinces. They are represented by deep-level plumbing systems consisting of giant dike swarms, sill provinces and layered intrusions.

<span class="mw-page-title-main">Brennisteinsfjöll</span> Volcanic system in Iceland

Brennisteinsfjöll is a minor volcanic system, with crater rows and small shield volcanoes on the Reykjanes Peninsula in southwest Iceland.

<span class="mw-page-title-main">Reykjanes</span> Geographic feature in Southwestern Iceland

Reykjanes is a small headland on the south-western end of the Reykjanes Peninsula in Iceland, giving the main peninsula its name. Volcanic action is responsible for forming the entire peninsula. The nearest town is Keflavik.

<span class="mw-page-title-main">Geological deformation of Iceland</span>

The geological deformation of Iceland is the way that the rocks of the island of Iceland are changing due to tectonic forces. The geological deformation help to explain the location of earthquakes, volcanoes, fissures, and the shape of the island. Iceland is the largest landmass situated on an oceanic ridge. It is an elevated plateau of the sea floor, situated at the crossing of the Mid-Atlantic Ridge and the Greenland-Iceland-Scotland ridge. It lies along the oceanic divergent plate boundary of North American Plate and Eurasian Plate. The western part of Iceland sits on the North American Plate and the eastern part sits on the Eurasian Plate. The Reykjanes Ridge of the Mid-Atlantic ridge system in this region crosses the island from southwest and connects to the Kolbeinsey Ridge in the northeast.

<span class="mw-page-title-main">Noronha hotspot</span>

Noronha hotspot is a hypothesized hotspot in the Atlantic Ocean. It has been proposed as the candidate source for volcanism in the Fernando de Noronha archipelago of Brazil, as well as of other volcanoes also in Brazil and even the Bahamas and the Central Atlantic Magmatic Province.

<span class="mw-page-title-main">Krýsuvík (volcanic system)</span> Volcanic region in Iceland

The volcanic system of Krýsuvík, also Krýsuvík-Trölladyngja volcanic system, is situated in the southwest of Iceland on the Reykjanes peninsula. It is located in the middle of Reykjanes and on the divergent plate boundary of the Mid-Atlantic Ridge which traverses Iceland. It was named after the Krýsuvík area which is part of it and consists of a fissure system without a central volcano. However, there are some indications—namely, the discovery by geophysical methods of what scientists interpret as a buried caldera, combined with the well-known, vigorous hydrothermal system above it—that an embryonic central magma chamber may already exist or be actively developing.

<span class="mw-page-title-main">Geology of Reykjanes Peninsula</span> Volcanic area of Iceland

The Reykjanes Peninsula in southwest Iceland is the continuation of the mostly submarine Reykjanes Ridge, a part of the Mid-Atlantic Ridge, on land and reaching from Esja in the north and Hengill in the east to Reykjanestá in the west. Suðurnes is an administrative unit covering part of Reykjanes Peninsula.

<span class="mw-page-title-main">Keilir (mountain)</span>

Keilir is a Pleistocene subglacial mound or perhaps a conical tuya on Reykjanes Peninsula in Iceland. Basal area is 0.773 km2, summit area 0.004 km2, basal width 0.99 km, summit width 0.07 km, volume 0.0362 km3.

<span class="mw-page-title-main">1996 eruption of Gjálp</span>

Gjálp is a hyaloclastite ridge (tindar) in Iceland under the Vatnajökull glacier shield. It originated in an eruption series in 1996 and is probably part of the Grímsvötn volcanic system, though not all the scientists involved are of this opinion.

<span class="mw-page-title-main">Plate theory (volcanism)</span>

The plate theory is a model of volcanism that attributes all volcanic activity on Earth, even that which appears superficially to be anomalous, to the operation of plate tectonics. According to the plate theory, the principal cause of volcanism is extension of the lithosphere. Extension of the lithosphere is a function of the lithospheric stress field. The global distribution of volcanic activity at a given time reflects the contemporaneous lithospheric stress field, and changes in the spatial and temporal distribution of volcanoes reflect changes in the stress field. The main factors governing the evolution of the stress field are:

  1. Changes in the configuration of plate boundaries.
  2. Vertical motions.
  3. Thermal contraction.

Intraplate volcanism is volcanism that takes place away from the margins of tectonic plates. Most volcanic activity takes place on plate margins, and there is broad consensus among geologists that this activity is explained well by the theory of plate tectonics. However, the origins of volcanic activity within plates remains controversial.

References

  1. ↑ Tobias Weisenberger (2013). "Introduction to the geology of Iceland".
  2. ↑ "Catalogue of the Active Volcanoes of the World, Vol. 24" (PDF). Archived from the original (PDF) on 2013-11-13. Retrieved 2012-08-01.
  3. ↑ Gunnar Karlsson (2000), Iceland's 1100 Years, p. 181
  4. ↑ How The Earth Was Made: The Age of Earth (video), History.com
  5. 1 2 3 4 Müller, R. Dietmar; Royer, Jean-Yves; Lawver, Lawrence A. (1993-03-01). "Revised plate motions relative to the hotspots from combined Atlantic and Indian Ocean hotspot tracks". Geology. 21 (3): 275. Bibcode:1993Geo....21..275D. doi:10.1130/0091-7613(1993)021<0275:rpmrtt>2.3.co;2. ISSN   0091-7613.
  6. 1 2 O'Neill, Craig; Müller, Dietmar; Steinberger, Bernhard (April 2005). "On the uncertainties in hot spot reconstructions and the significance of moving hot spot reference frames". Geochemistry, Geophysics, Geosystems. 6 (4): n/a. Bibcode:2005GGG.....6.4003O. doi: 10.1029/2004gc000784 . ISSN   1525-2027.
  7. 1 2 Martos, Yasmina M.; Jordan, Tom A.; Catalán, Manuel; Jordan, Thomas M.; Bamber, Jonathan L.; Vaughan, David G. (2018-08-24). "Geothermal Heat Flux Reveals the Iceland Hotspot Track Underneath Greenland" (PDF). Geophysical Research Letters. 45 (16): 8214–8222. Bibcode:2018GeoRL..45.8214M. doi:10.1029/2018gl078289. ISSN   0094-8276. S2CID   134080119.
  8. 1 2 Denk, Thomas; Grímsson, Friðgeir; Zetter, Reinhard; Símonarson, Leifur (2011-02-23), Introduction to the Nature and Geology of Iceland, 35, retrieved 2018-10-16
  9. ↑ Stein, Carol A; Stein, Seth (February 2003). "Mantle plumes: heat-flow near Iceland". Astronomy and Geophysics. 44 (1): 1.08–1.10. doi:10.1046/j.1468-4004.2003.44108.x. ISSN   1366-8781.
  10. ↑ Foulger, G. R.; Du, Z.; Julian, B. R. (November 2003). "Icelandic-type crust". Geophysical Journal International. 155 (2): 567–590. Bibcode:2003GeoJI.155..567F. doi: 10.1046/j.1365-246x.2003.02056.x . ISSN   0956-540X. S2CID   53983210.
  11. ↑ Símonarson, L. A., & Eiríksson, J. (2008). "Tjörnes-Pliocene and Pleistocene sediments and faunas". Jökull . 58: 331–342. doi: 10.33799/jokull2008.58.331 . S2CID   257224547.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ↑ Einarsson, Páll (2008). "Plate boundaries, rifts and transforms in Iceland" (PDF). Jökull. 58: 35–58. doi:10.33799/jokull2008.58.035. S2CID   55021384.
  13. ↑ Björnsson, A. (2005). "Development of Thought on the Nature of Geothermal Fields in Iceland from Medieval Times to the Present" (PDF). In Horne, R.; Okandan, E. (eds.). Proceedings World Geothermal Congress 2005. International Geothermal Association, Auckland, N.Z. ISBN   9789759833206.
  14. ↑ "Eruption in Iceland may mark the start of decades of volcanic activity". Archived from the original on March 22, 2021. Retrieved 27 March 2021.
  15. ↑ "Latest news on the volcanic eruption on the Reykjanes Peninula". Icelandic Meteorological office. 2023-07-10. Retrieved 2023-07-13.
  16. ↑ "Iceland volcano erupts on Reykjanes peninsula". BBC. 2023-12-19. Retrieved 2024-01-09.
  17. 1 2 3 4 5 Sigmundsson, Freysteinn; Einarsson, Páll; Hjartardóttir, Ásta Rut; Drouin, Vincent; Jónsdóttir, Kristín; Árnadóttir, Thóra; Geirsson, Halldór; Hreinsdóttir, Sigrún; Li, Siqi; Ófeigsson, Benedikt Gunnar (2020-02-01). "Geodynamics of Iceland and the signatures of plate spreading". Journal of Volcanology and Geothermal Research. 391: 106436. doi:10.1016/j.jvolgeores.2018.08.014. ISSN   0377-0273.
  18. 1 2 Baldursson, Snorri; Guðnason, Jónas; Hannesdóttir, Hrafnhildur; Þórðarson, Þorvaldur (2018). "Nomination of Vatnajökull National Park dynamic nature of fire and ice for inclusion in the World Heritage List" (PDF).{{cite journal}}: Cite journal requires |journal= (help)
  19. ↑ Björnsson, H., & Pálsson, F. (2008). "Icelandic glaciers" (PDF). Jökull. 58: 365–386. doi:10.33799/jokull2008.58.365. S2CID   257225342.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  20. ↑ Langmann, Baerbel; Folch, Arnau; Hensch, Martin; Matthias, Volker (2012). "Volcanic ash over Europe during the eruption of Eyjafjallajökull on Iceland, April–May 2010". Atmospheric Environment. 48: 1–8. Bibcode:2012AtmEn..48....1L. doi:10.1016/j.atmosenv.2011.03.054. ISSN   1352-2310.
  21. ↑ Jude-Eton, T. C.; Thordarson, T.; Gudmundsson, M. T.; Oddsson, B. (2012-03-08). "Dynamics, stratigraphy and proximal dispersal of supraglacial tephra during the ice-confined 2004 eruption at Grímsvötn Volcano, Iceland". Bulletin of Volcanology. 74 (5): 1057–1082. Bibcode:2012BVol...74.1057J. doi:10.1007/s00445-012-0583-3. ISSN   0258-8900. S2CID   128678427.
  22. 1 2 Ingólfsson, Ólafur; Benediktsson, Ívar Örn; Schomacker, Anders; Kjær, Kurt H.; Brynjólfsson, Skafti; Jónsson, Sverrir A.; Korsgaard, Niels Jákup; Johnson, Mark D. (2016-01-01). "Glacial geological studies of surge-type glaciers in Iceland — Research status and future challenges". Earth-Science Reviews. 152: 37–69. doi:10.1016/j.earscirev.2015.11.008. ISSN   0012-8252.
  23. ↑ Kjær, Kurt H.; Larsen, Eiliv; van der Meer, Jaap; Ingólfsson, Ólafur; Krüger, Johannes; Örn Benediktsson, Ívar; Knudsen, Carita G.; Schomacker, Anders (2006-11-01). "Subglacial decoupling at the sediment/bedrock interface: a new mechanism for rapid flowing ice". Quaternary Science Reviews. 25 (21): 2704–2712. doi:10.1016/j.quascirev.2006.06.010. ISSN   0277-3791.
  24. ↑ DeMets, Charles; Gordon, Richard G.; Argus, Donald F. (April 2010). "Geologically current plate motions". Geophysical Journal International. 181 (1): 1–80. doi:10.1111/j.1365-246X.2009.04491.x.
  25. 1 2 3 4 5 6 7 8 9 10 11 Soils, Society, and Global Change. Italy: United Nations University, Soil Conservation Service Icleand, JRC European Commission, IES. 2009. ISBN   978-92-79-11775-6.
  26. 1 2 3 4 "Forestry". www.government.is. Retrieved 2023-12-03.
  27. 1 2 3 "Soil Conservation". Government of Iceland. Retrieved 10 November 2023.
  28. 1 2 "The Mt. Hekla afforestation project". Hekluskógar. 2015-04-15. Retrieved 2023-12-03.
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