Why is it in the news?
- A state of emergency has been declared in Iceland due to a recent surge in seismic activity. This activity primarily occurred in the southwestern Reykjanes peninsula, an area known for its geological and volcanic significance.
- Seismic swarms are sequences of earthquakes that occur without a single, dominant “main shock.” They can last for weeks and involve numerous earthquakes within a relatively confined geographical area. Such swarms are observed in volcanic environments, hydrothermal systems, and other active geothermal regions.
Earthquake Swarms as Precursors to Volcanic Activity
- Deep beneath the Earth’s surface, the intense heat causes rocks to melt and form magma, a thick, flowing substance that is lighter than solid rock. This magma moves upward, with most of it being trapped in underground magma chambers.
- Over time, the magma cools and solidifies, but a small fraction can erupt through surface vents and fissures, leading to volcanic eruptions.
- The movement of magma, especially when it approaches closer to the Earth’s surface, exerts pressure on the surrounding rock. This pressure often results in earthquake swarms. However, it’s important to note that the underground movement of magma does not necessarily guarantee a volcanic eruption. The likelihood of an eruption increases as magma gets closer to the surface, and frequent earthquake swarms can be indicative of this process.
- Iceland is situated on the Mid-Atlantic Ridge, a divergent tectonic boundary where the Eurasian and North American tectonic plates are moving apart. This geological setting makes Iceland a region of significant seismic and volcanic activity.
- The Reykjanes peninsula, located in southwest Iceland, is characterized by vast lava fields, numerous volcanoes, and heightened geothermal activity. It is an area where the effects of tectonic plate movements and geological activity are particularly pronounced.
- Active volcanoes in Iceland are those that have erupted within the Holocene epoch, which began around 11,650 years ago, at the end of the most recent ice age. These volcanoes have the potential to erupt again in the future.
- In the Reykjanes peninsula, there had been no recorded volcanic eruptions for 800 years. However, this trend changed in recent years, with the Fagradalsfjall volcano witnessing a constant eruption over the past 2-3 years. This volcanic activity highlights the dynamic and unpredictable nature of Iceland’s geological landscape.
- Iceland is also known for other famous volcanoes like Eyjafjallajökull, which garnered international attention with its eruption in 2010, as well as Hekla, Grímsvötn, Hóluhraun, and Litli-Hrútur, which is part of the Fagradalsfjall volcanic system.