By ExploreNow Editor, on April 25th, 2012%
 Krafla Lake
Volcano Type: Caldera
Volcano Status: Historical
Last Known Eruption: 1984
Summit Elevation: 818 m 2,684 feet
Latitude: 65.73°N 65°44’0″N
Longitude: 16.78°W 16°47’0″W
The Krafla central volcano, located NE of Myvatn lake, is a topographically indistinct 10-km-wide caldera that is cut by a N-S-trending fissure system. Eruption of a rhyolitic welded tuff about 100,000 years ago was associated with formation of the caldera. Krafla has been the source of many rifting and eruptive events during the Holocene, including two in historical time, during 1724-29 and 1975-84. The prominent Hverfjall and Ludent tuff rings east of Myvatn were erupted along the 100-km-long fissure system, which extends as far as the north coast of Iceland. Iceland’s renowned Myvatn lake formed during the eruption of the older Laxarhraun lava flow from the Ketildyngja shield volcano of the Fremrinamur volcanic system about 3800 years before present (BP); its present shape is constrained by the roughly 2000 years BP younger Laxarhraun lava flow from the Krafla volcanic system. The abundant pseudocraters that form a prominent part of the Myvatn landscape were created when the younger Laxarhraun lava flow entered the lake.
Click Here For The Rest Of Krafla, Iceland
Originally posted 2010-08-24 04:15:21.
By ExploreNow Editor, on April 17th, 2012%
 Volcano Type: Stratovolcano
Volcano Status: Historical
Last Known Eruption: 1961
Summit Elevation: 1516 m 4,974 feet
Latitude: 65.03°N 65°2’0″N
Longitude: 16.75°W 16°45’0″W
Askja is a large basaltic central volcano that forms the Dyngjufjöll massif. It is truncated by three overlapping calderas, the largest of which is 8 km wide and may have been produced primarily from subglacial ring-fracture eruptions rather than by subsidence. A major rhyolitic explosive eruption from Dyngjufjöll about 10,000 years ago was in part associated with the formation of Askja caldera. Many postglacial eruptions also occurred along the ring-fracture. A major explosive eruption on the SE caldera margin in 1875 was one of Iceland’s largest during historical time. It resulted in the formation of a smaller 4.5-km-wide caldera, now filled by Öskjuvatn lake, that truncates the rim of the larger central caldera. The 100-km-long Askja fissure swarm, which includes the Sveinagja graben, is also related to the Askja volcanic system, as are several small shield volcanoes such as Kollatadyngja. Twentieth-century eruptions at Askja have produced lava flows from vents located mostly near Öskjuvatn lake.
Click Here For The Rest Of Askja, Iceland
Originally posted 2010-08-24 04:15:19.
By ExploreNow Editor, on April 4th, 2012%
Volcano Type: Subglacial volcano
Volcano Status: Historical
Last Known Eruption: 1918
Summit Elevation: 1512 m 4,961 feet
Latitude: 63.63°N 63°38’0″N
Longitude: 19.05°W 19°3’0″W
Katla volcano, located near the southern end of Iceland’s eastern volcanic zone, is hidden beneath the Myrdalsjökull icecap. The subglacial basaltic-to-rhyolitic volcano is one of Iceland’s most active and is a frequent producer of damaging jökulhlaups, or glacier-outburst floods. A large 10 x 14 km subglacial caldera with a long axis in a NW-SE direction is up to 750 m deep. Its high point reaches 1380 m, and three major outlet glaciers have breached its rim. Although most historical eruptions have taken place from fissures inside the caldera, the Eldgjá fissure system, which extends about 60 km to the NE from the current ice margin towards Grímsvötn volcano, has been the source of major Holocene eruptions. An eruption from the Eldgjá fissure system about 934 AD produced a voluminous lava flow of about 18 cu km, one of the world’s largest known Holocene lava flows. Katla has been the source of frequent subglacial basaltic explosive eruptions that have been among the largest tephra-producers in Iceland during historical time and has also produced numerous dacitic explosive eruptions during the Holocene.
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Originally posted 2010-08-24 04:15:29.
By ExploreNow Editor, on March 15th, 2012%
 Grímsvötn Volcano Volcano Type: Caldera
Volcano Status: Historical
Last Known Eruption: 2004
Summit Elevation: 1725 m 5,659 feet
Latitude: 64.42°N 64°25’0″N
Longitude: 17.33°W 17°20’0″W
Grímsvötn, Iceland’s most frequently active volcano in historical time, lies largely beneath the vast Vatnajökull icecap. The caldera lake is covered by a 200-m-thick ice shelf, and only the southern rim of the 6 x 8 km caldera is exposed. The geothermal area in the caldera causes frequent jökulhlaups (glacier outburst floods) when melting raises the water level high enough to lift its ice dam. Long NE-SW-trending fissure systems extend from the central volcano. The most prominent of these is the noted Laki (Skaftar) fissure, which extends to the SW and produced the world’s largest known historical lava flow during an eruption in 1783. The 15-cu-km basaltic Laki lavas were erupted over a 7-month period from a 27-km-long fissure system. Extensive crop damage and livestock losses caused a severe famine that resulted in the loss of one-fifth of the population of Iceland.
 - Grímsvötn Volcano
An ash plume rises from a new crater near the southern margin of Grímsvötn caldera in November 2004. Grímsvötn, Iceland’s most frequently active volcano in historical time, lies largely beneath the vast Vatnajökull icecap. The 6 x 8 km wide caldera is the source of frequent jökulhlaups (glacier outburst floods) produced when melting raises the water level high enough to lift its ice dam. Long NE-SW-trending fissure systems extend from the central volcano, including the noted Laki (Skaftar) fissure, which erupted in 1783.
Originally posted 2010-07-06 17:13:53.
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