Although earthquake activity is still very strong in Bárðarbunga caldera and the fissure in Holuhraun keeps spewing up huge amount of lava and volcanic gases, both events seem to be declining.
The Scientific Advisory Board of the Icelandic Civil Protection (SAB) has reviewed data from the beginning of the unrest in Bárðarbunga on August 16th and the start of the eruption in Holuhraun two weeks later, until the present day. Most of the data shows a decline in the subsidence of the large caldera and the volcanic eruption.
Subsidence and earthquakes at Bárðarbunga
According to SAB the earthquake activity in Bárðarbunga peaked in the first half of September and has slowly decreased since then. The activity however remains intense.
It’s noteworthy that the period of seismic unrest is one of the largest ever recorded in a volcano globally.
In the days following the onset of the seismic unrest in Bárðarbunga, the ice-covered base of the caldera began to subsidence up-to 80 cm (31 in) a day, but the subsidence has since slowed and it is now around 25 cm (10 in) per day, reports SAB. The subsidence is in the shape of a bowl on the surface and it is greatest in the centre of the caldera, about 50 m (164 ft.), but smaller around the edges.
Holuhraun’s massive lava flow
The eruption in Holuhraun is in an ice free zone about 41 km (25 mi) north of the sub-glacial volcano Bárðarbunga in Vatnajökull glacier.
The flow of lava from the eruption is not only great in comparison to other volcanic eruptions in Iceland over the last 200 years, but is also the fastest flowing lava eruption on the entire planet over the same time period.
According to SAB the petrology analysis of the magma suggests that it stabilized at 9-20 km (5.6 to 12.5 mi) depth, meaning it could not have resided at a shallower depth in the crust.
The new lava field in Holuhraun now covers more than 76 square km (29.3 sq. mi) and is still growing. For scale NY’s Manhattan Island is 59.5 square km (22.96 sq. mi).
This is the largest lava flow in Iceland since the Laki eruption (1783-1784) and it is probably the third largest lava field on the planet in modern times according to SAB.
It's estimated that Holuhraun has produced around 1 cubic km (0.24 cu mi) of lava with uncertainty of +/- 0.3 cubic km. For comparison the Puu Oo eruption in Hawaii has produced around 4 cubic km (0.96 cu mi) during the continuing 31 year-long eruption.
The lava flow in Holuhraun was about 200 cubic meters (7,063 cubic ft.) per second in September but the average flow rate for November is estimated to have been less than 100 cubic meters (3,542 cubic ft.) per second.
Volcanic gas pollution
For the first time in 150 years, gas pollution from a volcanic eruption has had an impact on Iceland reports SAB. The reason is the size and the duration of the eruption.
Fewer cases of high sulfur dioxide concentration have been recorded in populated areas over the last few weeks compared to September and October, but in those cases weather conditions may have had an equally large effect as the flux of gas coming from the eruption site.
According to SAB the subsidence of Bárðarbunga and the volcanic eruption on Holuhraun can continue in a similar fashion for at least some months before petering out. But a sub-glacial eruption in Bárðarbunga, or other parts of the 200 km (124 mi) long volcanic system, remains a possibility.
Although earthquake activity is still very strong in Bárðarbunga caldera and the fissure in Holuhraun keeps spewing up huge amount of lava and volcanic gases, both events seem to be declining.
The Scientific Advisory Board of the Icelandic Civil Protection (SAB) has reviewed data from the beginning of the unrest in Bárðarbunga on August 16th and the start of the eruption in Holuhraun two weeks later, until the present day. Most of the data shows a decline in the subsidence of the large caldera and the volcanic eruption.
Subsidence and earthquakes at Bárðarbunga
According to SAB the earthquake activity in Bárðarbunga peaked in the first half of September and has slowly decreased since then. The activity however remains intense.
It’s noteworthy that the period of seismic unrest is one of the largest ever recorded in a volcano globally.
In the days following the onset of the seismic unrest in Bárðarbunga, the ice-covered base of the caldera began to subsidence up-to 80 cm (31 in) a day, but the subsidence has since slowed and it is now around 25 cm (10 in) per day, reports SAB. The subsidence is in the shape of a bowl on the surface and it is greatest in the centre of the caldera, about 50 m (164 ft.), but smaller around the edges.
Holuhraun’s massive lava flow
The eruption in Holuhraun is in an ice free zone about 41 km (25 mi) north of the sub-glacial volcano Bárðarbunga in Vatnajökull glacier.
The flow of lava from the eruption is not only great in comparison to other volcanic eruptions in Iceland over the last 200 years, but is also the fastest flowing lava eruption on the entire planet over the same time period.
According to SAB the petrology analysis of the magma suggests that it stabilized at 9-20 km (5.6 to 12.5 mi) depth, meaning it could not have resided at a shallower depth in the crust.
The new lava field in Holuhraun now covers more than 76 square km (29.3 sq. mi) and is still growing. For scale NY’s Manhattan Island is 59.5 square km (22.96 sq. mi).
This is the largest lava flow in Iceland since the Laki eruption (1783-1784) and it is probably the third largest lava field on the planet in modern times according to SAB.
It's estimated that Holuhraun has produced around 1 cubic km (0.24 cu mi) of lava with uncertainty of +/- 0.3 cubic km. For comparison the Puu Oo eruption in Hawaii has produced around 4 cubic km (0.96 cu mi) during the continuing 31 year-long eruption.
The lava flow in Holuhraun was about 200 cubic meters (7,063 cubic ft.) per second in September but the average flow rate for November is estimated to have been less than 100 cubic meters (3,542 cubic ft.) per second.
Volcanic gas pollution
For the first time in 150 years, gas pollution from a volcanic eruption has had an impact on Iceland reports SAB. The reason is the size and the duration of the eruption.
Fewer cases of high sulfur dioxide concentration have been recorded in populated areas over the last few weeks compared to September and October, but in those cases weather conditions may have had an equally large effect as the flux of gas coming from the eruption site.
According to SAB the subsidence of Bárðarbunga and the volcanic eruption on Holuhraun can continue in a similar fashion for at least some months before petering out. But a sub-glacial eruption in Bárðarbunga, or other parts of the 200 km (124 mi) long volcanic system, remains a possibility.
