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	Volcano K-12 Experiments for Lesson Plans & Science Fair Projects
		Important exceptions exist in hotspot volcanoes, which occur at locations far from plate boundaries; hotspot volcanoes are also found elsewhere in the solar system, especially on its rocky planets and moons.
		Hotspots were originally a catch-all for volcanoes that didn't fit into one of the above two categories, but today this refers to a more specific circumstance - where an isolated plume of hot mantle material hits the underside of the crust, either (oceanic or continental).
		Iceland is sometimes cited as a third classical example, but complicated by the coincidence of a hotspot intersecting an oceanic ridge constructive margin.
	www.juliantrubin.com /encyclopedia/earthsciences/volcano.html (5881 words)

	Iceland & the N Atlantic Igneous Province
		Iceland is underlain by a low-wave-speed anomaly that all seismic tomography studies with good upper-mantle resolution agree extends only down to the mantle transition zone [e.g., Ritsema et al.
		Historically, crustal seismic data from Iceland have been interpreted both as indicating that the crust is thin and the mantle beneath hot (the “thin, hot” model), and that the crust is thick and the mantle beneath cool (the “thick, cold” model).
		A model whereby the Iceland melting anomaly is derived from shallow sources in the mantle and processes consequential to plate tectonics (see also Anderson [2001] and PT Processes page) is consistent with the absence of very high temperatures, the persistence of the melting anomaly on the mid-Atlantic ridge, the seismic tomography, crustal structure and geochemistry.
	www.mantleplumes.org /Iceland1.html (5076 words)

	WHOI : Oceanus : Hitting the Hotspots
		Hotspots are relatively small regions on the earth where unusually hot rocks rise from deep inside the mantle layer.
		A theoretical geodynamic model shows that a narrow hotspot "root," such as the one recently discovered beneath Iceland, would generate a vigorous source of heat (light colors) and produce a huge volume of magma that would migrate laterally along and across the ridge axes hundreds of kilometers away from the hotspot source.
		Iceland, the Azores, and the Galápagos are examples of these “hotspot” islands—so named because they are believed to form above small regions scattered around the earth where unusually hot rocks rise from deep inside the mantle layer.
	www.whoi.edu /oceanus/viewArticle.do?id=2396 (1567 words)

	Iceland (Site not responding. Last check: 2007-10-08)
		Iceland was formed by the spreading boundary of the North American and European plates and a hotspot or mantle plume.
		Despite the amassing of land in high latitudes, the world climate remained relatively mild because of the enormous increase in the size of the tropic seas and because of the fact that the land was not elevated sufficiently enough to produce glaciers.
		Iceland is also one of the most geologically active places in the world and that is why it is continually being used as a labratory of geologists and geology students the world over.
	www.oberlin.edu /~Geopage/projects/204projects/weaver/ICELAND.HTM (928 words)

	Hydrogen to the rescue? Questions about Iceland's sustainability \| EnergyBulletin.net \| Peak Oil News Clearinghouse
		Because of its geology and latitude, Iceland is disadvantaged agriculturally.
		The opposite argument is a massive cooling of Iceland’s climate, due to a stalled global conveyor belt, which is responsible for keeping Iceland as temperate as it is (9).
		If Iceland is successful in doing this, it would acquire so much financial and political capital that it could purchase oil for its ship imports at almost any cost, even if oil spikes to $100 or $200 a barrel.
	www.energybulletin.net /19791.html (1546 words)

	Volcano (Site not responding. Last check: 2007-10-08)
		Shield volcano: Hawaii and Iceland are examples of places where volcanoes extrude huge quantities of lava that gradually build a wide mountain with a shield-like profile.
		Iceland is sometimes cited as yet a third classical example, but complicated by the coincidence of a hotspot intersecting an oceanic ridge constructive margin.
		On the third hand, high-resolution seismology of different hotspots is yielding different pictures of the deep sub-structure of Hawaii versus Iceland.
	volcano.iqnaut.net (3495 words)

	Iceland hotspot - Wikipedia, the free encyclopedia
		The Iceland hotspot is a hotspot which is partly responsible for the high volcanic activity which has formed the island of Iceland.
		Iceland's location astride the Mid-Atlantic Ridge, where the Eurasian and North American Plates are moving apart, is partly responsible for this intense volcanic activity, but an additional cause is necessary to explain why Iceland is a substantial island while the rest of the ridge mostly consists of seamounts, with peaks below sea level.
		The plume, of which the Iceland hotspot is thought to be the surface expression, is believed to be quite narrow, perhaps 100 km across, and extends down to at least 400–650 km beneath the Earth's surface, and possibly down to the core-mantle boundary.
	en.wikipedia.org /wiki/Iceland_hotspot (443 words)

	Island Vulnerability, Iceland
		Iceland suffers from some main difficulties in risk management which afflict most countries, yet when a problem is tackled, the Icelanders quickly produce excellent results.
		Iceland, as with other countries, has a record of not accepting natural hazards to be threatening until after a catastrophe has occurred, usually with serious casualties.
		The volcano Eldfell, born in 1973, on the Icelandic island of Vestmannaeyjar.
	www.islandvulnerability.org /iceland.html (3377 words)

	Iceland’s recent ‘mega-flood’
		Icelanders call such sudden drainage events jökulhlaups, literally, ‘glacier bursts.’ It is these that lead to mega-scale flooding with devastating consequences.
		Iceland’s main high-tension power-lines were severed, and the telephone cables ripped apart.
		Iceland’s devastating November 1996 jökulhlaup testifies to the power of Noah’s Flood and that it can easily explain the building of the geological record.
	www.answersingenesis.org /creation/v21/i3/iceland.asp (1278 words)

	Volcanoes & Iceland (Site not responding. Last check: 2007-10-08)
		Iceland is a volcanic island built almost completely of cooled basaltic lava.
		Iceland is one of the few places in the world where a mid-ocean ridge is exposed above sea level.
		Geologists think that Iceland is above sea level because at this one place on Earth, the position of the mid-ocean ridge coincides with the position of a hotspot.
	www.casdn.neu.edu /~geology/department/staff/colgan/iceland/volcanos.htm (1358 words)

	CIW - News 991110
		For the Iceland plume, the answer is now in." The other authors of the paper are Yang Shen, the lead author (previously of Woods Hole and recently relocated to the University of Rhode Island), Cecily Wolfe (Woods Hole), and Ingi Bjarnason (University of Iceland's Science Institute).
		The Iceland plume is one of the most extensively studied plumes in the world.
		Their map of the upper mantle beneath the Iceland hotspot, based on seismic data gathered from an array of portable seismometers on the surface, showed that a cylinder of hot, upwelling material directly beneath Iceland occupies a slender zone about 300 km wide.
	carnegieinstitution.org /news_980902.html (904 words)

	A fiery debate about volcanoes (Site not responding. Last check: 2007-10-08)
		Estimates of the number of hotspots in the world range from a handful to more than a hundred, but most scientists agree to a list of several dozen.
		When a mid-ocean ridge moves right across a hotspot, as the Reunion hotspot in the Indian Ocean has done, the ridge doesn't excavate the hotspot; instead, volcanism jumps from one plate to the other.
		The evidence is strong for half a dozen hotspots, but others may owe their persistent existence to different mechanisms.
	www.lbl.gov /Science-Articles/Archive/ESD-volcanic-debate.html (1109 words)

	Honolulu Star-Bulletin Hawaii News
		In fact, they said, there may not be hotspots, that plate tectonics may explain volcanoes far from the edges of continental plates (such as Hawaii and Iceland) instead of lava rising from the Earth's mantle.
		Another theory is that the deep upwelling at the hotspot could be caused by a crack in the lithosphere (earth's crust) or weaknesses allowing the material to rise, she said.
		Some people think the hotspots are very narrow upwellings of solid rock from the mantle, she said, pointing out the rocks are buoyant and rise up because of hotter temperatures than normal.
	starbulletin.com /2003/05/11/news/story3.html (837 words)

	Reference.com/Encyclopedia/Volcano
		Volcanic activity can also occur from mantle plumes, the so-called hotspots, which occur at locations far from plate boundaries; hotspot volcanoes are also found elsewhere in the solar system, especially on its rocky planets and moons.
		Hotspots are not located on the ridges of tectonic plates, but on top of mantle plumes, where the convection of Earth's mantle creates a column of hot material that rises until it reaches the crust.
		Hawaii and Iceland are examples of places where volcanoes extrude huge quantities of basaltic lava that gradually build a wide mountain with a shield-like profile.
	www.reference.com /browse/wiki/Volcano (3566 words)

	Iceland hotspot
		hotspot which is partly responsible for the high volcanic activity which has formed the island of Iceland.
		Iceland is one of the most active volcanic regions in the world, with eruptions occurring on average roughly every five years.
		There is an ongoing discussion whether the hotspot is caused by a deep mantle plume or originates at a much shallower depth.
	www.vetty.com /wpcd/wp/i/Iceland_hotspot.htm (447 words)

	Buoyancy Explains How Volcanic Rock Rises Through the Earth's Mantle
		Because the ridge is adjacent to a volcanic hotspot on Iceland, the study also provides new information on how such heat sources affect ridges -- and may prompt reconsideration of existing models that explain such sea-floor spreading.
		"hotspots," which are point sources of high volcanic output associated with quasi-stationary and long-lived heat sources in the mantle.
		The mid-Atlantic ridge is an example of the former; Hawaii, Iceland and Yellowstone National Park are examples of the latter.
	www.spacedaily.com /news/tectonics-01f.html (927 words)

	Crustal Isostasy Indicates Anomalous Densities Beneath Iceland
		The high elevation of Iceland is due to the bouyancy associated with the hot, depleted, partially molten mantle produced by the Iceland plume and to its unusually thick crust (up to 40 km; Darbyshire et al., 1998).
		Many parts of Iceland are sampled, including the zero-age neovolcanic zones and the Tertiary age portions of extreme eastern and western Iceland (Figure 1).
		Petrological and seismic data indicate that the lower crust of Iceland and of the Mid-Atlantic ridge are very similar, suggesting that the density descrepancy between the plateaus and normal ridges arises from a difference between their respective mantles.
	www.ldeo.columbia.edu /users/menke/crust/index.html (2923 words)

	[No title] (Site not responding. Last check: 2007-10-08)
		Eight centuries of periodic volcanism at the center of the Iceland hotspot revealed by glacier tephrostratigraphy
		In comparison with other parts of the plate boundary in Iceland, eruption frequency is greater, episodes of unrest are longer, and intervals of low activity are shorter.
		When combined with historical data on eruptions and earthquakes, our data indicate that rifting-related activity in Iceland as a whole is periodic and broadly in phase with the volcanic activity within Vatnajökull.
	www.hi.is /~mmh/gos/geo.html (198 words)

	ScienceWeek
		This could mean that the Pacific plate was moving northward over a stationary hotspot source, carrying the volcanic record of the Emperor seamounts with it.
		If all Emperor seamounts were at 19ºN when they erupted, this would suggest that the hotspot source was fixed at 19ºN with respect to the North Pole and that there was northward motion of the Pacific plate.
		Seismological studies of the Yellowstone hotspot found no clear evidence for a lower mantle source, while evidence of a deep plume beneath the Iceland hotspot remains equivocal.
	scienceweek.com /2003/sb031010-4.htm (777 words)

	Seismic structure of the Iceland mantle plume
		Understanding the geometry of upwelling mantle flow and the characteristics of melting beneath hotspots and mid-ocean ridges is of fundamental importance for topics ranging from the formative processes for the crust and lithosphere to the large-scale dynamics and chemical makeup of the mantle.
		One of the most studied regions is Iceland, a hotspot centered on the Mid-Atlantic Ridge, yet previous seismological and geodynamic studies have been unable to constrain the width, temperature, and depth extent of the plume.
		This high-resolution upper mantle image indicates that Iceland is underlain by a hot and narrow plume of upwelling mantle.
	www.mbari.org /seminars/1998/may13_wolfe.html (218 words)

	ScienceDaily: Like A Balloon: Study Supports Buoyancy Explanation For How Volcanic Rock Rises Through The Earth's Mantle
		Hotspot (geology) -- In geology, a hotspot is a location on the Earth's surface that has experienced active volcanism for a long period of time.
		Hotspots were thought to be caused by a narrow stream of hot mantle...
		Continental crust -- The continental crust is the layer of granitic, sedimentary and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves.
	www.sciencedaily.com /releases/2001/08/010831081237.htm (2096 words)

	Baker - On the Global Distribution of Hydrothermal Vent Fields
		According to this criterion, possibly influential hotspots, besides Iceland and the St. Paul-Amsterdam system, include Galápagos, Easter, Jan Mayen, Azores, Ascension, Tristan de Cunha, Bouvet, and Crozet (Figure 1).
		Bouvet and Crozet are near the ultraslow spreading SWIR where the incidence of venting is already low and so the hypothesized "hotspot effect" on venting may be difficult to discern at these locations.
		Tristan de Cunha is distant from the MAR axis, while the effect of the Easter Island mantle plume may be further complicated by tectonic interactions with the adjacent microplate.
	www.pmel.noaa.gov /pubs/outstand/bake2544/hotspot_affected_ridges.shtml (647 words)

	The Iceland hotspot and the North Atlantic Igneous Province
		To understand the origin of the Iceland hotspot, we must look at the big picture and start from the continental-breakup magmatism that took place during the opening of the North Atlantic around 60 million years ago.
		This rather frequent formation of large igneous provinces during the disintegration of the supercontinent Pangea is a surface manifestation of the thermal and chemical state of convecting mantle beneath the supercontinent.
		It is less problematic, for example, to account for the proximity of the Iceland and the Jan Mayen hotspots, which are only ~800 km apart, by upper mantle heterogeneity than two closely-located plumes rising from the depth of ~3000 km.
	www.mantleplumes.org /Iceland3.html (4092 words)

	The American Museum of Natural History - EarthBulletin - Volcanoes - Geologic Setting
		Iceland's geology is among the most unique in the world.
		The country was formed because of an interaction between two separate geologic events: sea-floor spreading at a mid-ocean ridge and a hotspot -- from which lava sporadically erupts -- below the ridge.
		Instead, when the hotspot causes an eruption, the massive melting of the glacier produces huge floods.
	earthbulletin.amnh.org /A/5/2/index.html (294 words)

	Study Supports Buoyancy Explanation for How Volcanic Rock Rises Through the Earth's Mantle
		A new study of the Earth's mantle beneath the ocean near Iceland provides the most convincing evidence yet that simple buoyancy of hot, partially molten rocks can play an important role in causing them to rise and erupt through the surface at mid-ocean ridges.
		Because the ridge is adjacent to a volcanic hotspot on Iceland, the study also provides new information on how such heat sources affect ridges - and may prompt reconsideration of existing models that explain such sea-floor spreading.
		Hot upwelling of volcanic rock from the mantle typically occurs in two environments: (1) mid-ocean ridges, which are linear chains of volcanic activity along the boundary where two plates move away from one another, and (2) "hotspots," which are point sources of high volcanic output associated with quasi-stationary and long-lived heat sources in the mantle.
	gtresearchnews.gatech.edu /newsrelease/BUOYANT.html (867 words)

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