Iceland fissure eruption

Volcanic fissures in Iceland, such as the 2021 eruption at Fagradalsfjall, reveal the island's dynamic geology.

About this subject

Fissure eruptions are volcanic events where magma rises through long cracks in the Earth's crust, forming rows of craters and extensive lava flows. In Iceland, these eruptions occur mainly along rift zones where the Eurasian and North American tectonic plates diverge. One of the most devastating examples was the Laki eruption (1783-1784), which released toxic gases and led to a famine that killed about 20% of the Icelandic population. More recently, the 2021 Fagradalsfjall eruption on the Reykjanes peninsula drew thousands of visitors due to its accessibility and visual spectacle.

Icelandic fissure activity is closely monitored by volcanologists using seismic and GPS data to predict events. Eruptions can last weeks or months, forming vast basaltic lava fields. In 2023, new eruptions at Litli-Hrútur and Sundhnúksgígar continued to shape the landscape. The phenomenon also has climatic implications: fissure eruptions release sulfur dioxide that can temporarily cool the Northern Hemisphere, as seen after Laki.

Tourists and scientists benefit from aerial drone imagery, which enables real-time mapping of lava flow and crater evolution. Iceland invests in infrastructure for safe access to these sites, combining adventure tourism with geological education. Each renewed eruption is an opportunity to study the processes building oceanic crust.

Frequently Asked Questions

What causes fissure eruptions in Iceland?

They result from the divergence of the Eurasian and North American tectonic plates, creating fractures through which magma rises. Heat from the Earth's mantle melts rock, fueling these eruptions.

What is the most famous fissure eruption in Iceland?

The Laki eruption of 1783-1784, which produced 15 km³ of lava and released gases causing a devastating famine and altering global climate.

Is it safe to visit active fissure eruptions in Iceland?

Yes, with guidance from authorities. Areas are monitored and closed if risk increases. In 2021, Fagradalsfjall was accessible with marked trails and safety barriers.