Under the ice…A trip at Vatnajökull glacier
by Cristian Montanaro and Hannah Reynolds
A sweet breeze in the air… steam puffed from the rocks… a big hard sun in a blue sky… immense cauldrons, black-reddish spines and rolling hills in a sea of white all around us… that is what we saw on top of Grimsfjall in Vatnajökull on the last day of our expedition.
It all began on the 31th of May 2014 when a convoy of big jeeps, snow scooters and a Snowcat carried people of science, art and ice, up the slopes of Vatnajökull glacier.
This annual expedition to Vatnajökull is a joint effort between the University of Iceland, the Icelandic Met Office and the Iceland Glaciological Society. One aim of this expedition is to take care of the huts at Grimsfjall, located at 1724 m a.s.l..
These huts are the main refuge for people working on the glacier and are equipped with measurement stations such as GPS, anemometer, rain gauge and a seismometer. There is also an element of luxury with a shower and sauna which are heated by the geothermal system below. Scientists travel the glacier performing GPS profiling, taking ice core samples, and sampling and analysing gas emitted by volcanoes and many more research tasks.
Several central volcanoes are located beneath Vatnajökull, including Grímsvötn, Bárðarbunga and Kverkfjöll. Bárðarbunga recently became famous because of a seismic swarm which started on the 16th of August, and preceded the on-going fissure eruption at Holuhraun (north of Vatnajökull).
Grímsvötn is Iceland's most frequently active volcano, and is covered by a 200-m-thick ice shelf. Only the southern rim of this 6x8 km caldera is exposed, and this is where the two Grimsfjall huts are located.
The icy landscape around the caldera is monitored annually due to its ever-changing nature, with ice depressions and areas of steaming hot ground forming and disappearing due to the evolving geothermal system.
Kverkfjöll volcanic system comprises two dormant sub-glacial calderas and is characterized by geothermal areas around the northern caldera rim. On the 15th of August 2013 the geothermal lake “Gengissig” emptied spectacularly producing a flood (Jökulhlaup) and several small phreatic explosions. A couple of days were dedicated to surveying the deposits in the lake area to gain insight into the dynamics of the phreatic explosions, which are generally poorly studied and poorly understood. On the first day we explored the geothermal field area around the lake, which includes a number of boiling (or near-boiling) hydrothermal pools, sulphurous fumaroles, snow-fed warm melt-water streams, and hydrothermally altered ground. GPS measurements of the lake level were taken as well as the water temperature. We then visited the remaining, and not snow-covered, explosion craters and had a look at the ejecta. This was mainly composed of pyroclasts, lava fragments and volcanic bombs, and clayey materials coming from the underlying hydrothermally altered glacio-lacustrine deposit. On the second day samples were collected in the proximity of craters and ice cores were drilled to retrieve material from the deposit’s distal part to better characterize the fine ejecta dispersed in small fans 1 km north of the lake.
Furthermore we were both lucky to have ”a walk on the rope” to the site of Grímsvötn’s 2011 eruption. The site is marked by an elongate lake with a small island on one end, a scar in the glacier. Through the large valley we went, and down a steep slope we climbed while staring at the lake and at the beauty around us. Huge blocks of ice crumbled from the high walls of ice in the distance while cold wind cut us to the bone, but finally we reached the lake. All around were thick layers of pyroclasts, large blocks, sediment wave structures, impact craters and fumaroles… it was heaven and hell!
So, how was it to live in a hut for a week? Well, not that bad! In the morning we woke up to a tasty porridge and hot coffee, accompanied by some Icelandic song, to warm us up. In the evening, after a working day, a warm welcome was waiting for us…lovely people, a cold beer (can you imagine after a freezing day?) or a bit of good liquor, a warm stew or delicious lamb (besides many other hut treats!) are the perfect way to end a long and hard day!
But every story has to come to an end, and so finally after days of fun, work and adventure we had to depart.
No words can describe what we experienced, the wilderness of a freezing world sculpted in ice and the silence of the wind… but when the curtain opens what greets your eyes is an immense mantle of sparkling snow, a soft blanket surrounding you keeping away the troubles of the world… a window on a magical realm where the sun’s reflections play tag over the smooth and placid snow, while the rock giants silently observe… whoever goes in the Glacier of Lakes will never forget…
We would like to thank Magnus Tumi, who led this unforgettable expedition (and showed us how to break dance!), as well as all the other participants for sharing this unique experience with us.
