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Finally… a volcanic eruption!

Location: Iceland - July 2021

For the past 10 days, a low and grey cloud cover has hung over the Reykjanes peninsula in southwest Iceland. Earlier this afternoon, when our flight landed to Keflavik airport 40 km from the Icelandic capital Reykjavik, it was even foggy and we couldn't see anything. The peninsula's bizarre and spectacular volcanic landscape, an image we know all too well from our previous flights to Iceland, remained hidden from us this afternoon. The silent wish that the pilot would fly 'a round' around the volcanic eruption in the Geldingadalur valley was quickly gone…

For may days a low and grey cloud cover has hung of the Reykjanes peninsula.

I have always been fascinated by volcanoes, ever since learning about them at school. I have visited volcanoes in Java and Bali, in Santorini (Greece), made a helicopter landing in the active crater of White Island in New Zealand (read my blog: A voyage to Te Puia o Whakaari) and descended through the crater pipe into the magma chamber of the extinct Thrihnukagigur volcano in Iceland (read my blog: A journey to the center of the earth). However, experiencing a volcanic eruption up close was still high on my wish list but I knew this was a long shot, as the opportunities to do that safely are rare. The eruption in the Geldingadalur valley that started in March 2021 offered the opportunity to observe this natural spectacle up close in a safe way. Yet the Covid-19 pandemic threw a spanner in the works. Because the restrictive measures made traveling to Iceland impossible. Fortunately, we were able to follow the activities through various live webcams posted by Icelandic media!

Four months after the eruption started, my wife and I met the entry requirements and we were able to travel to Iceland.

Due to a strong wind, the drizzle hits the windshield of our car with gusts. The windshield wipers do their job. It is mid-July and with only 8 degrees, even for Icelandic standards, it is too cold for the time of year.

We postpone our first exploration trip to the volcanic area for a while. While we wait for the weather to improve, because the weather in Iceland can change very quickly, we decide to go through our documentation file again in the hotel and make a further travel plan for the next few days.

The documentation file, which I've compiled over the past four months since the start of the volcanic eruption, also includes a section on the geology of the volcanic area.

Reykjanes (see map) lies on a fault line between the Eurasian and American tectonic plates. The two sides of the fracture are moving away from each other by an average of 2 centimeters per year. The Geldingadalur valley is located in the Fagradalsfjall volcanic system (75 km² in area). This system originated more than 11,000 years ago and was inactive for more than 6,000 years until March 2021. The last volcanic eruption on the Reykjanes Peninsula took place 800 years ago.

The 2021 eruption was preceded by increasing seismic activity by more than a year. In the three weeks before the eruption, more than 40,000 smaller and more powerful earthquakes were recorded, the largest of which measured 5.6 on the Richter scale. Because the area is practically uninhabited, no damage was caused and there were no casualties. (Read my blog: A view below the surface of Reykjanes)

What has long been anticipated by geologists happened on Friday evening, March 19, 2021. In the Geldigadalur valley, just south of the dormant Fagradalsfjall volcano, the Earth's crust ripped open and red-hot magma found its way to the Earth's surface. Thus began the first fissure eruption and lava began to flow over the Geldingadalur and surrounding valleys.

Outflowing lava from the split crust in the Geldingadlur valley.

New fissures and 7 volcanic cones were formed in the weeks after the initial eruption and produced lava fountains up to 300 meters high. An average of 10 m³ of lava was emitted per second.

From the beginning of May, the eruption pattern of the then only active volcanic cone changed from a continuous eruption and lava flow to a pulsating one. Periods of eruptions alternated with periods of inactivity, with each cycle lasting from 10 minutes to half an hour. Over the summer, this pattern continued, forming a crater over 300 meters high!

Because a fissure eruption does not have violent explosions of lava, ash clouds and volcanic rock, you can get fairly close to the eruption. However, the risk of inhaling toxic gases remains.

Seven new cones were formed in the weeks after the initial eruption.

The weather gods are with us

In the evening the weather has cleared up reasonably well and the outlook for the next day has also been positively adjusted. It's mid-July and the days are long, so a good time to drive to the volcano area anyway for a short exploration. From our hotel it is a good 20 minutes drive to a makeshift parking lot. From there we look at the hiking possibilities and the condition of the route. From the parking lot it is a 4 kilometer walk to a first viewpoint with two steep climbs on improvised hiking trails…

We know enough!

The next morning it is dry and there is little wind. After a hearty breakfast we leave in time for the volcanic area and from the parking lot we start the walk up on a 'path' along the Nátthagi valley. The lava has also flowed into this valley and the view over the valley is impressive. The solidified lava has a thin crust in many places and close to the surface, the molten lava beneath it can reach a temperature of up to 1000 degrees. Yet we see people who take the risk and walk on the lava…

The Nátthagi valley is also flooded with lave from the eruption fissures in the nearby Geldingadlur valley.

Despite warnings, people still walk on the solidifies lava. In many places, the solidified crust is wafer-thin and beneath it flows liquid lava with a temperature of up to 1,000 degrees!

After a first tough steep climb, the active crater comes into our field of view. What an overwhelming image this is! We look for a place to sit, drink a cup of coffee from our thermos flask we brought with us and make a first series of shots. Then low-hanging clouds drift through the valley, blocking our view of the crater…

During another challenging climb the sky breaks open, the sun comes through and that is the prelude to an otherwise sunny and warm day for Icelandic standards!

After a steep climb we come face-to-face with the 300 meter high and now only active crater for the first time!

We reach the highest point of the ridge along the Nátthagi Valley from where we have an optimal view of the active crater.

We set up our cameras and can take beautiful pictures of today's very active volcano. At intervals of about 10 minutes, the volcano spews masses of liquid lava from the crater into the valley. What a spectacle!

At the highest point of the ridge along the Nátthagi valley we have a spectacular view of the active crater!

When we descend steeply from here to the valley to the edge of the solidified lava, we feel the heat coming towards us. A terrifying pop and hiss from the spewing volcano also increases.

How small and insignificant we feel when we can get so close to the fountains of fire and orange flowing lava rivers…

Only late in the afternoon we start the hike back. Descending the steep slopes is not without risks because there is no smooth path.

When we leave the valley behind, we look back one more time and realize that today we have witnessed a spectacle that is as fascinating as it is unique!

Lava tunnels

On September 18, the eruption stopped and until that moment 150 million m³ of lava has flowed out over an area of ​​4.8 km². In some places the lava layer is 100 meters thick! It is therefore very possible that lava tunnels will form here in the valleys. Hot lava flows like this can solidify very evenly on the outside. This limits the heat loss inside and allows the lava to continue glowing there. (That is why it is also very dangerous to walk on the lava here!). When the eruption stops, the lava eventually flows out from under the solidified crust, creating an empty tunnel. Over time, new lava may flow over it, causing an original lava tunnel to become deeper and deeper.

The entrance to a lava tunnel at Raufarhólshellir is about 50 kilometers from the eruption zone in Gerdingadalur.

A well-preserved lava tunnel close to the earth's surface is located in Raufarhólshellir, not far from the current eruption zone. This tunnel was created during the Leitharaun eruption, an eruption similar to the one in the Geldingadalir valley, but 5,200 years ago. The total length of this discovered tunnel is 1,360 meters, up to 30 meters wide and 10 meters high.

Perhaps in one of the valleys around the recent eruption, in the distant future, the same unique opportunity to visit a lava tunnel as now in Raufarhólshellir will arise and one will have the unique opportunity to see and experience up close the impressive natural forces, which emerged from the center of the earth in 2021.

The middle photo shows the traces of flowing lava.


-Journal of Volcanology and Geothermal Research. Edition 411 - The Reykjavik Grapevine – Iceland monitor - Institute of Earth Sciences, Reykjavik

Photo’s made with Nikon D5600 and Nikon P1000


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