Fagradalsfjall volcano (Reykjanes peninsula, Iceland): lava overflowed dam and cut off another hiking trail to eruption site
Sat, 18 Sep 2021, 04:1404:14 AM | BY: MARTIN
Lava flows crossed the hiking trail (image: @EIlyinskaya/twitter)
Aerial view of lava flows filling up the Nátthagi valley (bottom right) (image: @EIlyinskaya/twitter)
A new lava flow map depicts the affected area of hiking trail (image: @EIlyinskaya/twitter)
After the resumption of the effusive eruption at the current site one week ago, the activity shows signs of increasing.
Lava flows just before the overtook the artificial dam (image: @EIlyinskaya/twitter)
It proves a formation of new lava flows in the upper part of the Nátthagi valley that have continued to fill up the valley.
The effusion of lava continues at elevated discharge rate. This is most likely reflecting at higher pace of the lava that overtook the artificial dam, crossed the hiking trail and leading towards the southern ring road.
Nátthagi valley by now is largely filled with lava flows.
Fagradalsfjall volcano (Reykjanes peninsula, Iceland): high-resolution lava flow map update
Thu, 16 Sep 2021, 05:5905:59 AM | BY: MARTIN
A new lava flow map of the current eruption site has been published and updated today. The map depicts a spreading field of lava that continues to advance gradually and slowly filling up the valley of Nátthagi.
A new lava flow map of the current eruption from 15 September (image: @geoviews/twitter)
The lava flows have filled up valleys of the Geldingadalir, Meradalir, Meradalur and Nátthagi since the eruption started.
The picture also shows all artificial barriers marked as red lines.
Fagradalsfjall volcano (Reykjanes peninsula, Iceland): activity is back after 7 days of calm and illuminates sky over Grindavik
Tue, 14 Sep 2021, 03:2903:29 AM | BY: MARTIN
Fountaining continues at the lava field in Geldingadalir valley (image: @EIlyinskaya/twitter)
Glowing steam at the current eruption site from live webcam accompanies the activity at the time of this update (image: Youtube/RÚV)
Lava flow returned to the main crater (image: @szharangi/twitter)
After the longest break of 7 days of apparent calm in the effusive activity, it picked up again on 11 September as a new lava flow returned to the western flank of the main crater and continues to descend into the Geldingadalir valley.
Glowing steam illuminates the sky over Grindavik (image: @Vedurstofan/twitter)
Small lava fountains are being observed in the field of lava in the Geldingadalir valley and continue to erupt.
The activity quickly intensified accompanied by a strongly rising signal of volcanic tremor indicating rapid magma flux towards the surface.
Timelapse video of the returned effusive eruption on 11 September showing illuminated sky over Grindavik (source: @ar_etsch/twitter)
new eruption night view from Grindavik… 2021.09.11./12. amazing!#timelapse from footage: Veðurstofa Ísland#massiv #eruption #icelandvolcano #lava #volcano #iceland #icelanderuption #Geldingadalir #Fagradalsfjall #Meradalir pic.twitter.com/rgDj26Ib4U— Ar-etsch (@ar_etsch) September 12, 2021
Fagradalsfjall volcano (Reykjanes peninsula, Iceland): eruption continues with regular pulses of lava fountains
Thu, 26 Aug 2021, 16:1616:16 PM | BY: T
The eruption continues in a very similar way as during the past days, with alternating pulses of lava erupting from the vent and quiet phases, at a rhythm of 12-16 hours approximately between the lava pulses.
Lava fountain and two lava flows this morning at Fagradalsfjall in Iceland (image: RUV webcam)
During the active phases, the crater fills with lava and "boils" over, often forming fountains, and forms multiple lava flows on the surface.
This morning, a new lava flow made its way towards the south and then turned east, while a smaller lava flow emitted a bit further to the west continued southwards towards Natthagi valley (s. image).
The size of the cone is constantly growing although its diameter at the top has decreased. As a consequence of the smaller volume of the bowl-shaped crater, the lava fountains are rising taller.
Activity oscillates like heartbeat from almost absence to spectacular lava overflows
Update Thu 19 Aug 2021 17:42
Eruption in Iceland this evening (image: RUV live webcam)
The eruption continues with no signs of ending, even though it has been going through rhythmically alternating phases of very low to very high levels. Roughly every 24 hours, it changes from one to the other extreme.
Oscillating tremor reflecting the regular magma surges (image: IMO)
When it is high, the crater is filled with a lava lake that overflows on its rims and produces spectacular flows, as can be seen in the recent video below or in the view of the webcam right now (attached); when it is low, there is usually no visible activity at the surface.
Volcanologist Þorvaldur Þórðarson explained that these lava pulses are likely caused by large gas bubbles rising through the magma in the underground feeding system, pushing the magma out of the vent onto the surface.
Since these lava surges come at very regular intervals, these large gas bubbles must rise in very orderly pattern. Nature likes such regular processes and creates order,- think of the rhythmic behavior of geysers, for example.
The gas bubbles that are responsible for the peaks of activity at Fagradalsfjall are of course orders of magnitude larger than most similar phenomena. Likely, they originate at the top of the magma source in the upper mantle at 15-17 km depth, and once large enough to overcome a critical threshold of some sorts, they start rising and pushing the magma column upwards, resulting in the surface activity seen a short time after.