Posts Tagged ‘Bárðarbunga’

Lava flow continues from fissure eruption near Bárðarbunga

September 12, 2014

The fissure eruption continues in Iceland. The length of the lava stream is now about 16.8 km.

I am looking forward to visiting Iceland next week.

On 5th September:

Bardarbunga Photo taken 5th September at 0939 by Olafur Freyr Gíslason.

Bardarbunga Photo taken 5th September at 0939 by Olafur Freyr Gíslason.

  • The eruptive activity at Holuhraun continues at similar intensity. Lava flows at similar rates as yesterday. The lava is flowing towards East but widens slightly towards North. The main flow follows the river bed of Jökulsá á Fjöllum. No explosive activity due to the lava and river water interaction has been observed, but steam rises from the lava.
  • Forecasts indicate that high concentrations of sulphuric gases may be expected in the northern part of the Eastern fjords, Fljótsdalur, Hérað, Jökuldalur, and Vopnafjörður. High concentrations could occur in other areas as well.
The extent of the lava, Thursday morning. The edge (yellow line) is creeping closer to mountain Vaðalda

The extent of the lava, Thursday morning. The edge (yellow line) is creeping closer to mountain Vaðalda

 

Bárðarbunga, Iceland: A small fissure eruption has started north of Dynjujökull

August 29, 2014

A flight over the glacier has discovered a row of 10-15 m deep cauldrons south of the Bárðarbunga caldera. They form a long line. The cauldrons have been formed as a result of melting, possibly sub-glacial eruption, uncertain when. There are three circular crevasse formations, about 5 km in total length. The ice thickness in the area is 400-600 m. No signs of flooding have been detected.

Now a small fissure eruption further north has been detected.

The Aviation Colour Code remains at the ‘orange’ level for Bárðarbunga.

Iceland Met Office reports:

A fissure eruption has started north of Dynjujökull.

29th August 2014 02:45 – An eruption north of Dyngjujökull

An eruption started in Holuhraun north of Dyngjujökull at around 00:02. Seismic tremor was observed on all seismic stations and the web camera installed in the area by Mila has showed some nice pictures of the eruption.  It is a small fissure eruption and at 02:40 AM the activity appears to have decreased.

28th August 2014 18:14 – from geoscientist on duty

Since midnight over 1100 earthquakes have been detected by the automatic system. The dyke does not appear to have migrated further north since noon. The main activity is in the dyke and at similar depth as before (8-12km). One earthquake of M5 occurred at 08:13 AM by the northern rim of the Bardarbunga caldera. Two minutes earlier (08:11) another event of M3.9 occurred at a similar location. A few earthquakes were detected near Askja, the biggest one of M2.7.

28th August 2014 12:35 – from of the Scientific Advisory Board

Scientists from the Icelandic Meteorological Office and the Institute of Earth Sciences, together with representatives of the Civil Protection in Iceland, met today to discuss the on-going unrest at the Bárðarbunga volcano.

Conclusions of the Scientific Advisory Board:

  • This morning, there was a flight over the Bárðarbunga area and the surface of the glacier was surveyed. No changes to the ice crevasses southeast of Bárðarbunga, that were seen yesterdayevening, were observed. These crevasses were likely formed due to melting at the ice bottom.
  • The depressions have been located southeast of the Bárðarbunga caldera, in all likelihood within the water divide of the river Jökulsá á Fjöllum. There are three circular crevasse formations, about 5 km in total length. The ice thickness in the area is 400-600 m.
  • The water level in Grímsvötn Lake has been surveyed and has likely risen by about 5-10 m in the last days, which corresponds to an addition of 10-30 million m³ of water in the lake. A slight increase in conductivity in Köldukvísl River was measured this morning, but the cause is yet unknown. No change has been measured in the Hágöngulón lagoon, Jökulsá River and Skjálfandi River. It is assumed, that the water from the cauldron has flowed into the Grímsvötn Lake or the river Jökulsá á Fjöllum.
  • The seismic activity is similar to that of the last days. Around midnight, three earthquakes of magnitude around 4 were recorded and one of magnitude 5 at 08:13 this morning, all located within the Bárðarbunga caldera.
  • Shortly before 08:00 this morning, there was a slight increase in seismic activity in the Askja volcano. Changes in the stress field due to expansion caused by the dyke have an effect on the Askja area.
  • Since yesterday, the length of the dyke under Dyngjujökull has increased by 1-1.5 km to the north, which is considerably less than in the last days. The dyke has now reached the fissure system of the Askja volcano and GPS measurements indicate that the area there is greatly affected.
  • The conclusions from the meeting of the Scientific Advisory Board of the Icelandic Civil Protection will continue to be published at around noon, after the meeting, if necessary.
Iceland earthquake swarm 20140829

Iceland earthquake swarm 20140829

Iceland warns of potential eruption of Bárðarbunga volcano

August 19, 2014

We are due to visit Iceland next month but that may now depend on how this develops.

The Iceland Met Office has upgraded its warning about a potential eruption of Bárðarbunga volcano and said  there were “strong indications of ongoing magma movement”.

The intense seismic activity that started on 16 of August at Bárðarbunga persists. Very strong indications of ongoing magma movement, in connection with dyke intrusion, is corroborated by GPS measurements. There are currently two swarms: one to the E of Bárðarbunga caldera and one at the edge of Dyngjujökull just E of Kistufell. At 2.37 am on the 18th a strong earthquake (M4) was located in the Kistufell swarm.

This is the strongest earthquake measured in the region since 1996. As evidence of magma movement shallower than 10 km implies increased potential of a volcanic eruption, the Bárðarbunga aviation color code has been changed to orange. Presently there are no signs of eruption, but it cannot be excluded that the current activity will result in an explosive subglacial eruption, leading to an outburst flood (jökulhlaup) and ash emission. 

From Volcano Discovery:

The volcano is hidden beneath the northwestern part of the Vatnajökull glacier, and contains a 700-m-deep caldera that is hidden beneath ice and has extensive flank fissures, from where eruptions have taken place: the Veidivötn fissure extends for over 100 km to the SW, almost reaching Torfajökull volcano, while the Trollagigar fissure extends 50 km to the NE touching Askja volcano.

 

vatnajokull glacier and its volcanoes image wired.com

vatnajokull glacier and its volcanos image wired.com

The summary issued on Monday says that though intense earthquake swarm continues at Barðarbunga further movement of magma towards the surface has not been detected.

Summary written 18th August at 20:45

Since the onset of the earthquake swarm at Bárðarbunga on Saturday morning 16th August 03:00am, around 2.600 earthquakes have been detected with the earthquake monitoring network of the Icelandic Meteorological Office (IMO), of these around 950 since midnight (17/18th August). Several of these events were larger than magnitude 3. The swarm initially started in the Bárðarbunga caldera and has been migrating in two clusters towards the north and the east of the volcano.

On Sunday 17th of August, these two clusters were active east and north of Bárðarbunga. The activity in both clusters was migrating northeastwards. While the strongest events were located in the northern cluster, the highest number of events was detected in the eastern cluster. The strongest event since the onset of the swarm was detected on Monday morning 02:37 in the northern cluster. Detailed analysis revealed that its magnitude was 4.5 and it was felt in Akureyri and Lón. By Monday evening, activity has significantly decreased in the northern cluster.

The eastern cluster remains active. Two stronger pulses of activity have occurred between 10:45 and 12:00 as well as 16:50 and 17:30 this morning. Within the first pulse around noon, the cluster was again migrating northeastwards, most events are now located between Bárðarbunga and Kverkfjöll. As reported earlier, GPS ground deformation data has evidenced that the earthquake swarm is caused by magma intrusion.

Throughout the whole sequence until now (18th August at 20:45) the majority of events has been at 5-10km depth. No signs of migration towards the surface or any other signs of imminent or ongoing volcanic activity have been detected so far. IMO is monitoring the area around the clock very closely and will update in case of any changes.

 


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