Professor Lukáš Krmíček from FCE documented the birth of a volcano in Iceland
It will be approximately two weeks since the surface in Iceland split in two. This created a new volcano called Litli-Hrútur, or Little Ram. Professor Lukáš Krmíček from the Institute of Geotechnics at the Faculty of Civil Engineering of Brno University of Technology (FAST BUT), who is a member of an international volcanology team led by Thor Thordarson from the University of Iceland, went to investigate it. The volcano’s lava, which can usually only be found in the depths of the Atlantic Ocean in the Mid-Atlantic Ridge, provides information about the Earth's mantle. Lava samples could therefore reveal new information about the interior of our planet.
Professor Lukáš Krmíček from FCE BUT and other members of the volcanology team were the first to examine the volcanic area. The birth of the volcanic fissure not only helped them to document the process of volcanic formation, but also the possibility of obtaining new information about the Earth's interior. The volcano spilled a specific basaltic lava from the Earth's mantle located right under the crust. The specific mid-ocean ridge basalt lava is produced only in Iceland or in the middle of the Atlantic Ocean, where samples are difficult to obtain. And because humans can only drill to the dept of 12 kilometers, reaching merely the uppermost part of the Earth's crust, basaltic lava represents the best example of studying the Earth’s mantle.
Moreover, Iceland has an unusual position among all places with active volcanic activity due to its location. "It is a unique example of a volcanism above a mantle plume, the source of which lies at a depth of 2,900 kilometers at the interface of the Earth's mantle and core. It is also located above the divergent boundary of two lithospheric plates – the North American and Eurasian plates, which are moving away from each other at a rate of several centimetres per year.", explained Krmíček.
A discovery worth risking it for
Just as one does not simply walk into to Mordor, one does not easily get near the Litli-Hrútur volcano. The entire area was completely closed off for several days due to extreme air pollution and the expedition was under the supervision of a team of rescue workers as there were several dangers. In active volcanic areas, the temperature is too high and there is a lack of oxygen, which is partly displaced by carbon dioxide. The scientists carried gas detectors and wore special fireproof suits.
However, to collect the samples, they had to move very close to the volcanic cone whose walls could collapse at any time. The threat is reminiscent of a dam breaking – suddenly a large amount of low-viscosity lava, known by the Hawaiian term pāhoehoe, spills out, and there's no easy escape. A cone collapse is difficult to predict, and in this case, it happened only a few hours after scientists left the vicinity of the cone.
After the volcanic cone collapses, a second problem arises. After a quick lava flow, the surrounding vegetation undergoes rapid thermal decomposition, resulting in pockets of methane-hydrogen fusions that explode randomly. "It's quite scary when the ground starts shaking under your feet and a rock blows up a few metres behind you," said Krmíček. Against all odds, the team safely collected all the necessary samples and has now moved on to the phase of examining them to look even deeper into the Earth's interior.
|doc. Ing. Michal Kriška, Ph.D.