Bardarbunga Volcano Eruption (Month 3)

 

Original post and Month 2
 


 
Resources:

 
 


 
November 22, 2014, 4:11 p.m. Pacific: Aviation code: Orange. SO2 is still a consideration, and on the 18th the University of Iceland noted that it has been detected in Belgium, Austria, Switzerland, and Norway.

Per the scientists yesterday:

21.11.2014, 11:00 UTC – Conclusions of the Scientific Advisory Board of the Icelandic Civil Protection:
Attending: Scientists from Icelandic Met Office and the Institute of Earth Sciences University of Iceland along with representatives from the Icelandic Civil Protection, the Environmental Agency of Iceland and the Directorate of Health.

  • The volcanic eruption in Holuhraun continues to be strong. The activity is similar as it has been for the last two weeks but the lava flow is more fluctuating. The lava flow forms an extrusion to the east southeast. From mid-September the productivity of the eruption has decreased.
  • Seismic activity in Bardarbunga continues to be strong. The biggest earthquake that was detected since noon on Wednesday, 18. November at 00:26 was of magnitude M4,6. In total 16 earthquakes bigger then M4,0 were detected over the period and 39 earthquakes between M3,0-3,9. In total 170 earthquakes were detected in Bardarbunga since noon on Wednesday.
  • On Thursday, 20 November at 08:46 an earthquake of magnitude M1,9 was detected in the dyke. Three other earthquakes larger then M1,5 were detected in the dyke since Wednesday. In total 65 earthquakes were detected in the dyke over the period, which is more activity then has been detected over the past few weeks. Most of the earthquakes were detected in north end of the dyke but about 15 earthquakes, including the larger ones, were more to the south and under Vatnajokull glacier.
  • The subsidence of the Bardarbunga caldera and tectonics continues with similar rate as last few weeks. Tectonics movements show depression towards Bardarbunga.
  • Three scenarios are considered most likely:

  • The eruption on Holuhraun declines gradually and subsidence of the Bardarbunga caldera stops.
  • Large-scale subsidence of the caldera occurs, prolonging or strengthening the eruption on Holuhraun. In this situation, it is likely that the eruptive fissure would lengthen southwards under Dyngjujokull, resulting in a jokulhlaup and an ash-producing eruption. It is also possible that eruptive fissures could develop in another location under the glacier.
  • Large-scale subsidence of the caldera occurs, causing an eruption at the edge of the caldera. Such an eruption would melt large quantities of ice, leading to a major jokulhlaup, accompanied by ash fall.

Other scenarios cannot be excluded.

I was thinking that the comment about the subsidence of the caldera being toward Bardarbunga might mean that the caldera isn’t inflating, i.e., a crater eruption would be less likely (unless the heat melts through the ice). But they do also note that other fissures could develop elsewhere under the glacier. Today the Iceland Met Office notes things are pretty much the same but with variability in the seismicity. Something’s changing slightly in the magma system it appears. Time may tell what.
 

 


 

November 10, 2014, 11:03 a.m. Pacific: Aviation code: Orange.
 

 
Per the scientists today, the lava flow now covers 70 km2. Seismicity is still high, but the eruption continues at the same level as in recent weeks. The same three likely scenarios are mentioned:

Three scenarios are considered most likely:

  • The eruption on Holuhraun declines gradually and subsidence of the Bardarbunga caldera stops.
  • Large-scale subsidence of the caldera occurs, prolonging or strengthening the eruption on Holuhraun. In this situation, it is likely that the eruptive fissure would lengthen southwards under Dyngjujokull, resulting in a jokulhlaup and an ash-producing eruption. It is also possible that eruptive fissures could develop in another location under the glacier.
  • Large-scale subsidence of the caldera occurs, causing an eruption at the edge of the caldera. Such an eruption would melt large quantities of ice, leading to a major jokulhlaup, accompanied by ash fall.

Other scenarios cannot be excluded.

And here is a paper (PDF) by Reidar G. Trønnes, published four days ago on “The Bárðarbunga-Nornahraun eruption, Iceland – an ongoing demonstration of rifting and volcanism.”

 


 
Update, November 3, 11:17 a.m. Pacific: Aviation code: Orange. Blush – I put the November 2nd update in the Month 2 post. We’re straightened out now!

Conditions at the eruption are unchanged. The scientists have posted a couple of spectacular pictures from October 29th. Here’s one – check them out!
 

 


 

Update, November 2, 2:40 p.m. Pacific: Aviation code: Orange. Per the IMO geoscientist:

2 November 2014 12:00 – from geoscientist on duty

About 100 earthquakes have been observed in the Bárðarbunga area past 24 hours, slightly more than the day before. No quake was over magnitude five. Over ten quakes were over magnitude four, the largest M4.6 at 04:30. Activity is low in the intrusion. Webcameras show considerable activity at the eruption site.

There is a comparison between this eruption and that of Laki in 1783 up at the Geology In Motion blog.
 
November 1, 2014, 10:48 a.m. Pacific: Aviation code: Orange. The geoscientists at the Iceland Met Office have put together a chart of all seismicity in the region of the eruption since it began in August:
 
event-numbers_31102014_1900

Those large magnitudes at the caldera, of course, would be expected for so much movement in a large geological structure.

Otherwise, the eruption is hidden by weather conditions, but no changes are noted.

October 31, 2014, 12:14 p.m. Pacific: Aviation code: Orange. Per the scientists today:

31.10.2014, 11:00 UTC – Conclusions of the Scientific Advisory Board of the Icelandic Civil Protection:
Attending: Scientists from Icelandic Met Office and the Institute of Earth Sciences University of Iceland along with representatives from the Icelandic Civil Protection, the Environmental Agency of Iceland and the Directorate of Health.

  • The volcanic eruption in Holuhraun continues with similar intensity. The lava field is now 65,7 squere kilometres [sic].
  • Seismic activity in Bardarbunga continues to be strong. 200 earthquakes have been detected in the caldera over the last 48 hours. Just over ten earthquakes were bigger then magnitude M4,0. The largest one was M5,3 tonight at 01:30.
  • The GPS station in the centre of Bardarbunga show that the subsidence of the caldera continues with similar rate as it has done over the last few weeks. The total depression in the caldera is now about 42 meters [roughly 138 feet].
  • Energy of the geothermal areas in Bardarbunga is now few hundred megawatts and the melting of water is estimated around 2 cubic meters per. second. The water goes into Skjálfandafljót og Jökulsá á Fjöllum. The flow is too small to effect the total water flow of the rivers.
  • Around 20 smaller earthquakes are detected in the dyke and at the eruption site in Holuhraun, all around magnitude M1,0 and smaller.
  • GPS measurements in the active area show minor changes.
  • A recommendation by the Scientific Advisory Board of the Icelandic Civil Protection: The Scientific Advisory Board concludes that it is necessary to increase monitoring of SO4 so it is possible to evaluate the concentration of sulphuric acid particles and its potential influence on health.

Until reading that and doing a bit of research, I didn’t realize that sulfur aerosols from a volcano can affect global climate even if they’re not blasted into the stratosphere (which Bardarbunga definitely hasn’t done). Per the USGS:

…the explosivity of an eruption and the amount of ash injected into the stratosphere are not the main factors in causing a change in Earth’s climate. Instead, scientists concluded that it must be the amount of sulfur in the erupting magma.

The eruption sure is pumping out a lot of sulfurous gas. And…
 

 


 

October 30, 2014, 11:59 a.m. Pacific: Aviation code: Orange. Here’s the latest Iceland Met Office update:

30 October 2014 10:00 – from geoscientist on duty

The last 24 hours the seismicity in Bárðarbunga has been a slight more than the day before. More than 100 earthquakes have been detected, all under M5. Ca 10 were larger than M4. The largest one was M4.6 at 16:09 yesterday. Ca 10 quakes were between 3 and 4. Seismicity in the northern part of the dike is similar to last days.

Visibility to the eruption is good and no changes can be seen.

October 29, 2014, 10:37 a.m. Pacific: Aviation code: Orange. We’re going into month 3 of the Holuhraun eruption at Bardarbunga. In Iceland. Where people have drones. It’s awesome!
 

Per the scientists today,

29.10.2014, 11:00 UTC – Conclusions of the Scientific Advisory Board of the Icelandic Civil Protection:
Attending: Scientists from Icelandic Met Office and the Institute of Earth Sciences University of Iceland along with representatives from the Icelandic Civil Protection.

  • The volcanic eruption in Holuhraun continues with similar intensity.
  • Seismic activity in Bardarbunga continues to be strong. 130 earthquakes have been detected in the caldera over the last 48 hours. Around ten earthquakes were between magnitude M4-5. Two were larger then M5,0 on the 28. October. The former at 04:54 and the latter at 06:04.
  • The GPS station in the centre of Bardarbunga show that the subsidence of the caldera continues with similar rate as it has done over the last few weeks.
  • Smaller earthquakes are detected in the dyke and at the eruption site in Holuhraun.
  • GPS measurements in the active area show minor changes.
  • No change was detected in water monitoring that cannot be explained by changing weather.

Three scenarios are considered most likely:

  • The eruption on Holuhraun declines gradually and subsidence of the Bardarbunga caldera stops.
  • Large-scale subsidence of the caldera occurs, prolonging or strengthening the eruption on Holuhraun. In this situation, it is likely that the eruptive fissure would lengthen southwards under Dyngjujokull, resulting in a jokulhlaup and an ash-producing eruption. It is also possible that eruptive fissures could develop in another location under the glacier.
  • Large-scale subsidence of the caldera occurs, causing an eruption at the edge of the caldera. Such an eruption would melt large quantities of ice, leading to a major jokulhlaup, accompanied by ash fall.

Other scenarios cannot be excluded.

Also…
 



Categories: volcanoes

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