Latest status report - eruption continues with little changes
Update Thu 04 Sep 14:47The intensity of the ongoing eruption in Holuhraun is not declining, the Icleandic Met Office reports in the latest status update:
"Lava is flowing toward ENE and it has been elongated considerably since yesterday. Since this morning, a preliminary estimate of lava field extension is about 10.8 km2.
- Seismic activity is still detected in the northern part of the dyke intrusion, along the eruption site and extending south below Dyngjujökull. Event rates are lower than in recent days, 180 earthquakes have been detected since midnight until noon. Four events larger than M4 have been detected in Bárðarbunga caldera. The largest one (M4.8) occurred last night at 03:09.
- The low frequency tremor seen yesterday disappeared last night but started again this morning, however minor compared to yesterday. The source of the tremor is not certain however possible explanation could be magma-water interaction although this interpretation has currently not been confirmed by other observations.
- There are no signs of a subglacial eruption under Dyngjujökull. No obvious changes such as increased water flow or cauldrons on the glacier surface were observed from scientists on board TF-SIF yesterday. Water meters in Jökulsá á Fjöllum do not show any unusual changes in discharge and electric conductivity.
- The GPS time series indicate slower rate of deformation in the last 24 hours. The current deformation pattern north of Vatnajökull still suggests volume increase in the dyke. No significant signs of deformation are observed around Bárðarbunga.
- There have been no observations of ash-fall away from the eruption site. Ash production is negligible.
- Sulphur dioxide emission continues. Low-wind speed condition is present in the area at the moment. Based on radar images the eruption cloud from today (composed of steam and volcanic gases) has not drifted far away and is mostly concentrated around the eruption site. Stations measuring SO2 further away from the eruption site are showing concentration below health and safety thresholds. Since this morning, the cloud reaches 6 km of altitude. The volcanic cloud will drift towards south in the coming hours due to wind rotation."
GPS measurement show significant horizontal deformation between Aug 31-Sep 2 indicating volume increase in dyke (image: @uni_iceland)
SO2 plume from the Holorgaun fissure eruption (ESA)
Tremor drops, activity might be subsiding
Update Thu 04 Sep 10:46
It is far from clear what is currently happening at the eruption. Tremor (indicator of magma moving) stopped yesterday evening around 21:30 local time and has not reappeared according to the Icelandic Met Office. This could indicate that the eruption is subsiding although webcam imagery suggested it continued with no apparent big change during the night.
Earthquakes around Bárdarbunga today so far (IMO)
Authorities are on alert for a possible subglacial eruption.
Earthquakes both under the caldera of Bárdarbunga central volcano, around Askja volcano and under the intrusion below the edge of the ice continue at reduced intensity.
The biggest event of the night was magnitude 4.8 earthquake in northern Bárðarbunga.
The eruption is currently not visible from cameras because of fog. Around 4 o'clock visibility was better and it activity appeared to be the same as before.