The Ultimate Guide to Icelandic Volcanoes: What Every Volcano Lover Should Know

If you're fascinated by fire-breathing mountains, Iceland should be at the top of your list. With over 130 volcanoes scattered across its wild, raw landscape, this island is one of the most volcanically active places on Earth. This handy guide breaks down what makes Iceland’s volcanoes so special, from the science behind their formation to the famous eruptions that shook the world.

Why Iceland Is a Hotspot for Volcanoes

Iceland’s dramatic volcanic activity comes from a unique combination of geological forces. The country straddles the Mid-Atlantic Ridge, where the Eurasian and North American tectonic plates are slowly pulling apart. As the plates separate, magma rises to the surface to fill the gap, forming new crust and occasionally erupting as lava.

On top of that, Iceland sits directly over a hotspot, an upwelling of extra-hot material from deep inside the Earth’s mantle. This hotspot supercharges the volcanic activity already happening along the plate boundary, creating a perfect storm for frequent eruptions.

This powerful combo is why Iceland averages an eruption every four to five years and why so much of its landscape looks like it was formed yesterday, because in many places, it was.

Types of Volcanoes in Iceland

One of the things that makes Iceland such an attractive destination for volcano fans is the variety of volcano types packed into a relatively small area.

Stratovolcanoes, such as Hekla, are tall, steep, and constructed from layers of hardened lava and ash. These are the classic cone-shaped volcanoes, known for their reputation for explosive eruptions.

Shield volcanoes are broad and gently sloped, made by runny lava that can travel long distances. Skjaldbreiður is a textbook example, massive but not particularly steep.

Fissure volcanoes erupt through long cracks in the ground rather than a central crater. Laki, which caused one of the deadliest eruptions in history, is a famous example.

Subglacial volcanoes lie beneath glaciers. When these erupt, the interaction of lava and ice can cause sudden, violent floods called jökulhlaups. Katla and Grímsvötn are two of the most active of this type.

Caldera volcanoes form when a volcano collapses in on itself after a massive eruption, leaving behind a crater-like depression. Askja is one of the most iconic calderas, complete with a surreal crater lake.

Iceland’s Most Famous Volcanoes

Volcanoes are everywhere in Iceland, but a few have made headlines around the world.

Eyjafjallajökull became a household name in 2010 when its eruption disrupted air travel across Europe. Though not especially large, its ash cloud was a stark reminder of how Icelandic volcanoes can impact far beyond the island.

Katla, hiding under Mýrdalsjökull glacier, is one of the most powerful volcanoes in the country and has a reputation for large, violent eruptions.

Hekla has been erupting since Iceland was settled and was once feared as the gateway to hell. It’s unpredictable and closely monitored.

Grímsvötn holds the record for Iceland’s most frequent eruptions. It’s also under a glacier, making it a prime suspect for jökulhlaups (glacier floods).

Þríhnjúkagígur, while dormant, is a rare geological wonder. You can actually descend into its empty magma chamber, the only place on Earth where that’s possible.

Eruptions That Shaped Iceland, and the World

Iceland's history is dotted with eruptions that have had both local and global consequences.

The Eldgjá Eruption (939 AD)

Considered the largest lava flow in the last two millennia, the Eldgjá fissure eruption spewed out more lava than any other eruption in Icelandic history. It likely impacted the climate and may have been recorded in medieval chronicles.

The Laki Eruption (1783-1784)

This was one of the most catastrophic volcanic events in human history. Over eight months, a 27-kilometer-long fissure opened, releasing approximately 15 cubic kilometers of lava. The eruption produced massive clouds of toxic gas, killing about 20% of Iceland’s population due to famine and disease. The resulting climate effects led to crop failures across Europe and even contributed to global cooling.

Askja (1875)

The explosive eruption of Askja covered much of East Iceland with volcanic ash, causing major damage to farmlands. This eruption triggered a wave of emigration, as many Icelanders left the country for North America due to the devastation.

Eyjafjallajökull (2010)

While not the largest eruption, Eyjafjallajökull’s 2010 eruption gained international fame because of the ash cloud it produced, disrupting air travel across Europe for weeks. It served as a reminder of how Iceland’s volcanoes can have a global impact.

The recent eruptions at the Reykjanes Peninsula

After almost 800 years of dormancy, the Reykjanes Peninsula entered a new volcanic era in 2021. This southwestern corner of Iceland, situated near Keflavík International Airport, is part of the Mid-Atlantic Ridge, where the Eurasian and North American tectonic plates meet.

Fagradalsfjall eruptions (2021–2022)

The eruption at Fagradalsfjall, which began on March 19, 2021, marked the first volcanic activity on the Reykjanes Peninsula in over 800 years. This event was particularly notable for its accessibility and relative safety. Located just a short drive from Reykjavík, the eruption quickly became a popular destination for both locals and tourists, offering a rare opportunity to witness lava flows in person.

This was a fissure eruption, characterized by lava emerging through cracks in the earth’s surface rather than from a central volcano. The lava was fluid and basaltic, flowing slowly across the landscape. There were no explosive events, and the eruption posed no immediate threat to infrastructure.

After several months of activity, the eruption paused in September 2021, only to briefly resume in August 2022. While relatively small in scale, the Fagradalsfjall eruption was significant for signaling the reawakening of the Reykjanes volcanic system.

Litli-Hrútur (2023) and Sundhnúkagígar (2023–2024)

The volcanic activity continued in July 2023 with a new eruption near Litli-Hrútur, followed by another fissure eruption in December 2023 at Sundhnúkagígar, northeast of the town of Grindavík. These eruptions confirmed that the Reykjanes Peninsula had entered an active phase of volcanic activity.

Both eruptions shared common characteristics with the earlier Fagradalsfjall event: they were effusive, meaning they produced flowing lava rather than explosive ash clouds. They also created new lava fields across previously untouched terrain, contributing to the ongoing reshaping of the peninsula's landscape.

While scientists and authorities closely monitored these eruptions, they did not pose an immediate threat to populated areas. However, temporary road closures and localized gas pollution occasionally impacted nearby communities.

Grindavík and the 2024–2025 eruptions

Beginning in late 2023, the Sundhnúkur crater row near Grindavík became the focus of continued volcanic unrest. A series of eruptions in this area extended into 2024 and 2025, with the most recent outbreak occurring in April 2025. These eruptions are part of the Svartsengi volcanic system, which lies beneath and around the town of Grindavík and the nearby Blue Lagoon.

Unlike earlier eruptions, this latest series of events has had more serious consequences. Repeated lava flows have posed risks to roads, pipelines, and buildings, and residents of Grindavík have faced multiple evacuations due to concerns over both lava flow and ground instability. Infrastructure has been damaged, and some lava flows have come dangerously close to residential zones.

These ongoing eruptions represent a shift like volcanic activity on the Reykjanes Peninsula, from relatively isolated lava flows in uninhabited areas to events that can have direct impacts on populated communities. As a result, the Icelandic Meteorological Office and civil protection authorities have heightened surveillance and response measures in the region.

Geologists now believe that the peninsula may be entering a new volcanic era, potentially marked by decades of intermittent eruptions. This pattern mirrors activity seen in other parts of Iceland’s geological history, such as in the 12th and 13th centuries.

How Scientists Monitor Iceland’s Volcanoes

Volcanic eruptions may seem unpredictable, but scientists have developed a range of tools to detect when magma is in motion. In Iceland, volcano monitoring is led by the Icelandic Meteorological Office and university geoscientists working in real-time.

The primary methods include:

• Seismic monitoring: Sensitive seismometers track earthquakes, which often occur as magma shifts underground.

• GPS and satellite data: Instruments detect changes in land elevation, signaling that the ground is swelling due to rising magma.

• Gas measurements: Elevated levels of volcanic gases, such as sulfur dioxide, can indicate that an eruption is imminent.

• Thermal imaging: Satellites and drones monitor temperature changes that could suggest magma is nearing the surface.

All this data is used to issue alerts, adjust risk levels, and coordinate with civil protection agencies. When activity increases, hazard zones are set up, roads may be closed, and if necessary, evacuations are ordered well in advance.

Signs an Eruption May Be Coming

No one can predict exactly when a volcano will erupt, but there are typical warning signs that scientists watch for:

• Increased earthquake activity beneath a volcano, especially swarms of small quakes.

• Ground deformation occurs as the land swells from rising magma.

• Steam or gas emissions are intensifying from fumaroles or vents.

• Cracks or fissures are forming in the surface near the volcano.

These signs can build up over days, weeks, or even months. In some cases, eruptions happen quickly after warning signs appear; in others, the magma may cool and harden underground without erupting at all. That’s why continuous monitoring is key.

Is It Safe for Travelers to Visit Iceland?

Iceland is one of the safest countries in the world to visit, despite its active volcanoes, due to its world-class monitoring system, swift emergency response, and a culture that knows how to coexist with nature’s extremes.

Most volcanic activity happens in remote, uninhabited areas. When eruptions do occur closer to towns or travel routes, authorities respond quickly with road closures, warnings, and evacuation plans. Tourists are kept well-informed through official websites, mobile alerts, and hotel staff.

If you’re planning to visit during active volcanic periods, it’s smart to:

• Check the Icelandic Meteorological Office’s website for real-time updates.

• Respect all road closures and hazard signs.

• Avoid venturing off marked trails in volcanic zones.

In many cases, eruptions become safe attractions, drawing visitors eager to witness nature at its most dramatic. The 2021–2022 Fagradalsfjall eruption, for example, was accessible and spectacular, with viewing trails established for safe lava-watching.

Living With Fire: How Volcanoes Define Iceland

From shaping the land to influencing folklore, volcanoes are deeply woven into Iceland’s identity. They power geothermal energy, inspire awe, and occasionally wreak havoc. But they also attract millions of curious visitors every year. Iceland offers a front-row seat to the planet’s most dramatic natural forces. And with the Reykjanes Peninsula entering a new era of activity, there’s never been a more exciting time to explore it.

At Lava Show, we aim to bring this powerful story to life. Through live lava demonstrations and educational content from Lava Academy, we help you get closer to the Earth’s raw power, safely and up close.