From Wikipedia, the free encyclopedia - View original article
Iceland has a high concentration of active volcanoes due to its location on the mid-Atlantic Ridge, a divergent tectonic plate boundary. The island has 30 active volcanic systems, of which 13 have erupted since the settlement of Iceland in AD 874.
The most fatal volcanic eruption of Iceland's history was the so-called Skaftáreldar (fires of Skaftá) in 1783-84. The eruption was in the crater row Lakagígar (craters of Laki) southeast of Vatnajökull glacier. The craters are a part of a larger volcanic system with the subglacial Grímsvötn as a central volcano. Roughly a quarter of the Icelandic nation died because of the eruption. Most died not because of the lava flow or other direct effects of the eruption, but from indirect effects, including changes in climate and illnesses in livestock in the following years caused by the ash and poisonous gases from the eruption. The 1783 eruption in Lakagígar is thought to have erupted the largest quantity of lava from a single eruption in historic times.
The eruption under Eyjafjallajökull ("glacier of Eyjafjöll") in 2010 was notable because the volcanic ash plume disrupted air travel in northern Europe for several weeks; however this volcano is minor in Icelandic terms. In the past, eruptions of Eyjafjallajökull have been followed by eruption of the larger volcano Katla, but after the 2010 eruption no signs of an imminent eruption of Katla were seen.
The eruption in May 2011 at Grímsvötn under the Vatnajökull glacier sent thousands of tonnes of ash into the sky in a few days, raising concerns of a repeat of the travel chaos seen across northern Europe.
The eruption series that started on August 17, 2014 under the Bárðarbunga system, started with an extremely heavy earthquake swarm followed by clusters of volcanic activity that have been going continuously since. This resulted in multiple lava fountain eruptions in Holuhraun  Lava flow is between 250 cubic meters per second and 350 cubic meters per second and comes from a dyke over 40 km long. There is little to no ash output from this eruption so far. The primary concern with this eruption is large plumes of sulphur dioxide (SO2,) in the atmosphere that are causing breathing conditions across Iceland, depending on wind direction.
The smooth flowing basaltic lava Pāhoehoe is in Iceland called helluhraun,[Islandsbok 1] it forms rather flat surfaces that is quite easy to pass.