– Up to 130 meter high lava fountains (RUV, Sep 4, 2014):
Robust activity has been seen in the Holuhraun lava eruption this morning, says volcanologist Armann Hoskuldsson who is monitoring the event. “The highest lava fountains rise up to 130 meters from the craters,” he says. The new lava field is now estimated to be 11 – 12 square kilometers in size.
“We returned to the fissure early this morning and saw considerable volcanic activity at around 7 AM,” says Dr. Hoskuldsson. He and other scientists spent the night at a mountain hut nearby, after an evacuation was ordered yesterday when volcanic tremor was detected in the area, leading to fears that a subglacial eruption was imminent. “The main craters are now very active and the lava fountains from them rise up to 120 – 130 meter height,” he says.
The new lava from the fissure now extends to about 11 – 12 square kilometres says dr. Hoskuldsson. “It´s been robust in the last hours and lava has been flowing westward by about 300 meters. The fissure itself has not changed much however; it´s still 1.7 – 1.8 kilometer long,” he says.
Despite the volcanic tremor yesterday, no signs of a subglacial eruption have been seen, and no change has been observed in water flowing from beneath the glacier. The tremor is still unexplained, but indications point to an area south of Holuhraun, extending under the Dyngjujokull glacier margin where a small rift valley (graben) has formed. One possible theory, according to scientists, is that groundwater has seeped through deep cracks in the bedrock, down to the magma intrusion beneath, causing explosive activity detected by seismometers.
According to the Icelandic Met Office (IMO), GPS measurements indicate that the volume of magma entering the dike intrusion is still more than the volume of lava being erupted at the Holuhraun fissure. The rate of magma being pumped in seems however to have slowed , says Benedikt Ofeigsson, a geophysicist at the IMO.
Seismic activity is still ongoing at Holuhraun, but the strongest earthquakes have been detected near the rim of the Bardarbunga volcano. Four earthquakes, exceeding magnitude 4 have occurred there since midnight. The strongest one was M4,8 according to the IMO.
This story, by the Icelandic National Broadcasting Service (RUV), was updated on 4 September 2014, at 12.30 GMT.