Monika Misztela is a PhD candidate in the Experimental Petrology group at RSES. She is currently involved in a project about the Platinum Group Element geochemistry and fertility of magma systems.
Iceland is a small country in the North Atlantic Ocean with a population of about 365 000 people and over twice as many sheep. The country of fire and ice, trolls, whales, puffins, wild horses, mushrooms, northern lights, waterfalls, glaciers, volcanoes, lava flows, geysers and plate tectonics. For me, Iceland is one of the most beautiful places I have ever visited. I had a chance to spend there three weeks, soon after the Eyjafjallajökull volcano eruption in 2010. As an undergrad student, this trip taught me more in 3 weeks than general geology course in the whole year. Having such a big impact on me, I would like to share some of the trip’s highlights with you.
The Mid-Atlantic Ridge is a divergent plate boundary and a part of the longest chain of mountains on Earth. The vast majority is hidden underwater but the largest portion above the sea level is exposed on Iceland, which was formed from volcanic eruptions about 24 million years ago. The ridge is crossing Iceland and separating North American and Eurasian Plates. It has an average of spreading of c.a. 2.5 cm per year, and it causes mantle material to move towards the surface, decompress and partially melt. More volcanic activity in the area results from the coinciding occurrence of the mid-ocean ridge and mantle plume underlying the island.
The eruption of Eyjafjallajökull was all over the news (it doesn’t happen very often in Europe…), and it caused lots of air travel disruptions. As the volcano is covered with an ice cap, it caused the ice melt, which then caused flooding. This stratovolcano is composed of basalts and andesites, and it is a part of a chain of volcanoes along the tectonic divergence of the Mid-Atlantic Ridge. It is also related to another volcano – Katla, laying 25 km east. From history, we know that each time Eyjafjallajökull erupted, it was shortly followed by another eruption by Katla. Researchers believe there is a high chance we will witness another eruption very soon.
Results of the volcanic activity can be observed all over the island. One of the Icelandic wonders is definitely hexagonal basalt column formations like the ones observed at Aldeyjarfoss or Reynisfjara. The long straight ones are called colonnade, and the more irregular ones – entablature. Both types are formed during the cooling of magma when it contracts around “centres” that are equally distributed. In that case, it formes the hexagonal pattern of fractures. However, if the “centres” are not evenly distributed, fractures may have 5 or 7 surfaces. It is known that water enhances this type of cooling.