Monday, Apr 14, 2014
A shallow (around 8 km depth) earthquake swarm including two quakes at 2.7 and 2.9 magnitude has started in an area 12 km to the south of Hekla volcano. ... [more]
Hekla volcano1491-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.
Background: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.
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