A scientist brought hot lava samples from Iceland to Brno

When information about a new erupting volcano arrived from Iceland on 3 August, geologist Lukáš Krmíček did not wait a minute. He contacted his foreign colleagues and a week later they were already planning together on the spot how and from where to remove the hot lava. Accompanied by rescuers and with special equipment, they set off for the Meradalir volcano. While tourists could watch the fire show from a distant hill, a scientist from the BUT was scooping up the hot magma. He brought the still-hot samples back to Brno this week.

Why did the eruption happen? From what depth did the magma come? What to expect in the future? While the first two questions may be of interest only to scientists, the third is something that every Icelandic has been asking themselves lately. For after 800 years of calm, a period of volcanic activity is likely to begin, right on the Reykjanes peninsula, where most of Iceland's population lives. Volcanic experts want to understand the volcanoes better so that they can better predict what is coming.

"My task was quite adventurous, taking samples of the flowing lava and then cooling them. The temperature of such lava is well over a thousand degrees. I wore a volcanology suit, a head shield and had a special sampling rod with me," says Lukáš Krmíček from the Faculty of Civil Engineering at the BUT. Thanks to his research, he was able to go where tourists are forbidden to go. At the same time, he was under the supervision of rescuers and colleagues Thor Thordarson from the University of Iceland and Valentin Troll from the University of Uppsala in Sweden.

VOLCANO LIVE, VOLCANO KILLER

"Professor Troll has been monitoring the concentrations of volcanic gases in my area, it's carbon dioxide and sulphur dioxide. These gases can be really dangerous and have killed before, for example in 1783 when Laki volcano erupted and killed up to a quarter of the island's population. The eruption resulted in very cold summers and crop failures in Europe, leading to famine and, because of social unrest, the French Revolution," the scientist points out the seemingly hidden link.

The volcano is under the watchful eye of scientists who measure the speed and direction of the lava's advance, flying over it with drones. Webcams transmit live views into the volcano, and tourists take unforgettable snapshots from nearby. The latter, according to fresh Professor Krmíček, sometimes start to descend closer to the volcano, where they are especially at risk of carbon dioxide suffocation. The subtle killer fills the valley and can be fatal without proper equipment.

Walking on the freshly solidified lava crust is not recommended either, as Krmíček experienced first-hand: "I went to look at the already solidified rim of the lava outpouring of 2021 while exploring the terrain around the volcano. I cut my hand on the so-called volcanic glass, which is very sharp. Fortunately, it was nothing serious."

LAVA AS THE FINGERPRINT OF OUR EARTH

Despite the minor setbacks and the fact that the volcano forced them to retreat several times, the scientists succeeded in sampling the lava. The hot lava is dropped into a steel bucket of water, which starts boiling immediately. While the sample is already cool on the surface, the temperature inside is still quite high for a long time.

The next part of the research will be studying the samples, which Lukáš Krmíček will be helped with, for example by colleagues from the Faculty of Chemistry at the BUT. I will also grind them into a fine powder and this will be further analysed for isotopic composition. We will separate elements such as strontium or lead," explains the geologist.

The samples carry a kind of fingerprint, a unique piece of information about which elements and at what depth the magma was formed. While the deepest borehole reached about 12 kilometres below the surface, the source of Iceland's magmas can lie hundreds of kilometres down into the centre of the Earth. This provides a unique opportunity for scientists to study the Earth's mantle.