The Icelandic Met Office has downgraded the aviation alert for Bardarbunga, from red to orange, meaning that eruption is not imminent. Subglacial eruption is not thought to have occurred yesterday. Seismic activity is still strong and the dyke intrusion in Dyngjujokull has propagated to the north.
Icelandic Met Office (IMO) said this around 12.00 GMT, after a meeting with scientists and the Civil Protection Agency. The aviation alert was raised yesterday to red, but has now been downgraded to orange. Observations show that a sub-glacial eruption did not take place yesterday as previously thought and the low-frequency seismic signal observed has other explanations.
The dyke intrusion under Dyngjujokull, north and east of the Bardarbunga caldera has however been propagating to the north, and is now believed to be about 30 kilometers long. A 4.2 earthquake was detected there this morning, along with numerous other quakes. Since midnight, more then 700 quakes have been detected in the area. IMO says no indication that the seismic activity is slowing down; therefore an eruption can not be excluded.
Two strong earthquakes occured in the Bardarbunga caldera last night and this morning (Magnitude 5,3 and 4.6). These quakes are associcated with pressure changes in the magma chamber beneath the caldera as magma flows out to the intrusion.
The Civil Protection Agency (CPA) declared an emergency phase yesterday and extended the restricted area north of Vatnajokull. CPA will reassess the situation later today.
Source: www.ruv.is
Iceland24
Expert: Likely no eruption yet
The IMO has changed the aviation color code from red back to orange. No visible sign of eruption but seismic activity still ongoing.
Geoscientists in Iceland seem to be of differing opinion regarding the small eruption that is believed to have taken place today. The Iceland Met Office said today that an eruption had likely taken place, but a professor of geophysics at University of Iceland sees no signs of an eruption.
A group of scientists surveyed the glacier today from the air, aboard a surveillance plane from the Icelandic Coastguard. After the flight, Magnus Tumi Gudmundsson, professor of geophysics at University of Iceland, was interviewed at RUV.
„The most likely scenario is that an eruption has not begun. This morning we saw a large increase in seismic activity and tremors, so it was perfectly rational to assume that an eruption had begun. A subglacial eruption melts the ice and causes floods. We surveyed the glacier for three hours today. I can of course not assert that nothing has happened, but it is clear that there are no signs of abnormal melting or other signs that normally appear during a subglacial eruption. It is therefore likely that the magma has not reached the surface yet - regardless of what will happen later in this process, because this is a fairly large event and those who delay to give timely warnings can carry a large responsibility.
Therefore, it was considered proper to be careful today but when more information comes in, the most likely conclusion is that an eruption has not begun, whatever happens later in this event,“ said Magnus this evening on RUV television newscast.
„The most current information I have is that the latest GPS deformation measurement shows that the dyke intrusion is getting wider and getting longer. That means that magma is still moving. Whether that results in an eruption or not, only time can tell. If we look at the Krafla eruptions, which are the most similar eruptions, we had a lot of dyke intrusions there at the beginning, but much smaller volcanic activity. We don´t know if this activity will show a similar pattern, but we have to be prepared. This run-up is positive in a way, because we have had time to prepare. There are no tourists in the area, so it´s positive that the process has not been more rapid. And of course, we all hope that this will end without an eruption and the ensuing damage.
“The dyke intrusion has been forming over the last few days. It is now believed to be around 25 km. long, and about 0,2 - 0,3 cubic kilometers of magma is thought to have entered the intrusion from a magma chamber beneath the Bardarbunga caldera. The intrusion has been propagating towards the north: it´s lenght seems to have increased by several kilometers just today.
At this stage measurements taken are based on a small event. The Jökulsárgljúfur canyon has been closed and evacuation of tourists in that area and around Dettifoss waterfall has started. The situation at this stage does not call for evacuation of habitants in Kelduhverfi, Öxarfjördur and Núpasveit. People in those areas are encouraged to watch news closely and have their mobiles switched on at all times.
Source: www.ruv.is
Iceland24
Geoscientists in Iceland seem to be of differing opinion regarding the small eruption that is believed to have taken place today. The Iceland Met Office said today that an eruption had likely taken place, but a professor of geophysics at University of Iceland sees no signs of an eruption.
A group of scientists surveyed the glacier today from the air, aboard a surveillance plane from the Icelandic Coastguard. After the flight, Magnus Tumi Gudmundsson, professor of geophysics at University of Iceland, was interviewed at RUV.
„The most likely scenario is that an eruption has not begun. This morning we saw a large increase in seismic activity and tremors, so it was perfectly rational to assume that an eruption had begun. A subglacial eruption melts the ice and causes floods. We surveyed the glacier for three hours today. I can of course not assert that nothing has happened, but it is clear that there are no signs of abnormal melting or other signs that normally appear during a subglacial eruption. It is therefore likely that the magma has not reached the surface yet - regardless of what will happen later in this process, because this is a fairly large event and those who delay to give timely warnings can carry a large responsibility.
Therefore, it was considered proper to be careful today but when more information comes in, the most likely conclusion is that an eruption has not begun, whatever happens later in this event,“ said Magnus this evening on RUV television newscast.
„The most current information I have is that the latest GPS deformation measurement shows that the dyke intrusion is getting wider and getting longer. That means that magma is still moving. Whether that results in an eruption or not, only time can tell. If we look at the Krafla eruptions, which are the most similar eruptions, we had a lot of dyke intrusions there at the beginning, but much smaller volcanic activity. We don´t know if this activity will show a similar pattern, but we have to be prepared. This run-up is positive in a way, because we have had time to prepare. There are no tourists in the area, so it´s positive that the process has not been more rapid. And of course, we all hope that this will end without an eruption and the ensuing damage.
“The dyke intrusion has been forming over the last few days. It is now believed to be around 25 km. long, and about 0,2 - 0,3 cubic kilometers of magma is thought to have entered the intrusion from a magma chamber beneath the Bardarbunga caldera. The intrusion has been propagating towards the north: it´s lenght seems to have increased by several kilometers just today.
At this stage measurements taken are based on a small event. The Jökulsárgljúfur canyon has been closed and evacuation of tourists in that area and around Dettifoss waterfall has started. The situation at this stage does not call for evacuation of habitants in Kelduhverfi, Öxarfjördur and Núpasveit. People in those areas are encouraged to watch news closely and have their mobiles switched on at all times.
Source: www.ruv.is
Iceland24
Small eruption believed to have started
The Icelandic Met Office says a small subglacial eruption started today beneath the Dyngjujokull outlet glacier, near the Bardarbunga caldera. Scientists aboard a surveillance airplane above the glacier see no signs of an eruption yet. All flight traffic has however been banned near the volcano.
Kristin Jonsdottir, geophysicist at the Icelandic Met Office says that this morning, increased seismic activity and increased tremor was observed around the Bardarbunga caldera, especially in a 25 km. long dyke intrusion north and east of the caldera, near the edge of the Dyngjujokull outlet glacier.
Shortly after 2 PM GMT, the Met Office declared an aviation alert for a large area around Bardarbunga and said a small eruption was believed to have started under the glacier. No signs of glacial flood has been observed and scientists in a surveillance airplane above the glacier see no sign on the surface of the glacier. Even so, the measurements indicated a small eruption under the glacier and it is now believed that it was small enough, not to cause significant melting of glacial ice. A larger eruption can not be ruled out, according to the Met Office.
The dyke intrusion has been forming over the last few days. It is now believed to be around 25 km. long, and about 0,2 - 0,3 cubic kilometers of magma is thought to have entered the intrusion from a magma chamber beneath the Bardarbunga caldera.
At this stage measurements taken are based on a small event. The Jökulsárgljúfur canyon has been closed and evacuation of tourists in that area and around Dettifoss waterfall has started. The situation at this stage does not call for evacuation of habitants in Kelduhverfi, Öxarfjördur and Núpasveit. People in those areas are encouraged to watch news closely and have their mobiles switched on at all times.
Source: ruv.is
August 2014
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