volcanodiscovery/bardarbunga/seismic-crisis-2014/updates.html The volcanic eruption at Holuhraun gives no signs of weakening and continues to eject an impressive lava fountain from the central Baugur crater at a rate similar to the past few weeks. This record-breaking eruption started on the 31st of August 2014 and formed a more than 17 km long lava flow. Using the successive outlines of this lava flow as drawn on a radar image from the Icelandic Coast Guard, researchers from the Institute of Earth Sciences estimated that by now the lava has covered an area of 70 km². Subsidence of the glacier surface above the Bárðarbunga caldera is also still going on. This vertical displacement is monitored by near real time presentation of data from a GPS station that was mounted in the centre of the caldera on September 11. There was a technical problem that prohibited transmission of these GPS data on the 8th of November, but this has been fixed. Comparison of the vertical location of this GPS station before and after the ca. 24 h communication problem shows subsidence of up to half a meter in a single day. The total subsidence recorded at Bárðarbunga caldera since 12 September is 21 m and based on earlier GPS data the total subsidence since the onset of this eruption is at least 44 m. The area’s seismic activity is also continuing at a similar intensity. On November 7 there was a M 5.4 earthquake at the northeastern rim of the caldera and this was the first earthquake over magnitude 5 since the 2nd of November. Since then, 15 earthquakes between magnitude 4 and 5 occurred, as well as quite a few between M 3 and M 4. Lower seismic activity is also observed at the intrusion, the largest earth quake of which was of magnitude 2.5.
Posted on: Sun, 09 Nov 2014 22:48:51 +0000
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