Bárðarbunga: Iceland’s Powerhouse of Fire and Ice

Bárðarbunga is one of Iceland’s most powerful and active volcanoes. Hidden beneath the vast Vatnajökull glacier, this subglacial giant has shaped Iceland’s landscape for thousands of years, producing some of the country’s largest eruptions.

Geological Facts About Bárðarbunga

Bárðarbunga, which is classified as a subglacial stratovolcano, rises to 6,591 feet, making it the country’s second-highest peak after Hvannadalshnjúkur. It belongs to the Bárðarbunga–Veiðivötn system, which stretches for more than 118 miles across the vast Icelandic landscape. At its core lies a massive caldera measuring about 27 square miles and plunging to depths of nearly 2,789 feet.

Bárðarbunga is capable of both effusive eruptions, producing expansive lava flows, and explosive eruptions that generate ash and tephra. Geologically, it sits at the boundary where the Eurasian and North American tectonic plates meet, directly above a hotspot beneath the Vatnajökull glacier, which fuels its remarkable activity.

A History of Powerful Eruptions

Bárðarbunga has a long history of eruptions that have reshaped Iceland’s landscapes over millennia. Around 6600 BC, it produced the Þjórsá Lava, the largest Holocene lava flow on Earth, which covered 950 square kilometers. In 877 AD, shortly after Iceland’s settlement, the Vatnaöldur eruption occurred with a Volcanic Explosivity Index (VEI) of 4. Perhaps the most significant event came in 1477, when the Veiðivötn eruption, Iceland’s largest known, reached a VEI of 6.

Between 1701 and 1864, Bárðarbunga experienced a series of smaller eruptions beneath the glacier and nearby fissures, marking a particularly active period. A major eruption followed in 1910 at the Loki-Fögrufjöll area, and in 1996 the Gjálp fissure eruption suggested possible connections between Bárðarbunga and the nearby Grímsvötn volcano. Even in more recent times, Bárðarbunga has shown signs of unrest. In 2010, an earthquake swarm of more than 30 quakes, some reaching a magnitude of 3.7, reminded scientists of the volcano’s ongoing activity.

The 2014–2015 Eruption

Bárðarbunga’s most recent eruption, which lasted from August 2014 to February 2015, was one of Iceland’s most remarkable modern volcanic events. The eruption occurred at the Holuhraun fissure, located just north of the main caldera, and produced approximately 0.4 cubic miles of lava. This created a new lava field covering 33 square miles, the largest in Iceland since the catastrophic Laki eruption of 1783–1784.

The event was accompanied by extraordinary seismic activity, with more than 30,000 earthquakes recorded. It also released vast amounts of sulphur dioxide into the atmosphere, lowering air quality across Iceland and reaching as far as mainland Europe. During the eruption, the Bárðarbunga caldera collapsed by up to 213 feet, a sign of the immense magma movement taking place beneath the glacier.

The Impact of Bárðarbunga’s Eruptions

The consequences of Bárðarbunga’s eruptions extend well beyond the immediate lava and ash. Explosive eruptions, such as the one in 1477, spread tephra across vast regions, blanketing the landscape and altering ecosystems. Subglacial eruptions carry the added risk of jökulhlaups, sudden glacial outburst floods that reshape valleys, move massive amounts of sediment, and change the downstream terrain. The gases released can also pose significant challenges. During large eruptions, these emissions not only affect air quality in Iceland but can also drift across borders, influencing conditions in other parts of Europe.

Signs an Eruption May Be Coming

Before Bárðarbunga erupts, it usually shows a range of warning signs. Swarms of earthquakes are one of the most common indicators, caused by magma forcing its way through the Earth’s crust. Scientists also track changes in the shape of the land, as the ground can rise or sink when magma builds below the surface. In a subglacial setting, unusual melting or shifting of the surface ice may also signal rising heat. Increased emissions of gases such as sulphur dioxide provide another clue that magma is nearing the surface. By piecing together these signs, volcanologists can often forecast when Bárðarbunga is becoming restless.

Is It Dangerous to Visit Iceland During a Volcanic Eruption?

Despite the dramatic nature of Iceland’s eruptions, the country remains remarkably safe for visitors. Bárðarbunga, for example, is located far beneath the Vatnajökull glacier, far from towns and villages. When eruptions occur near settlements, as in the recent eruptions on the Reykjanes Peninsula, Icelandic authorities act quickly by closing access to unsafe areas and issuing gas warnings.

Travelers in Iceland during an eruption are not in danger as long as they follow official guidance. While ash and sulphur dioxide can sometimes affect air quality, Iceland’s civil protection system and real-time updates from the Icelandic Meteorological Office ensure that risks are communicated clearly and that travel remains safe in most regions.

How Scientists Monitor Volcanoes

A network of surveillance systems constantly monitors Bárðarbunga and other volcanoes in Iceland. Sensitive seismographs detect earthquakes deep underground, giving early clues of magma movement. GPS instruments track subtle shifts in the Earth’s surface, while satellites provide detailed images of both the glacier and the land beneath it. Scientists also measure gas emissions, especially sulphur dioxide, to see whether magma is rising. Additionally, scientists closely monitor Vatnajökull, as sudden melting or floods can indicate hidden eruptions.

Together, these tools enable Icelandic scientists to track Bárðarbunga’s behavior in real-time, providing crucial warnings before eruptions escalate.

Bárðarbunga Compared to Other Volcanoes

To understand Bárðarbunga’s power, it helps to compare it with other well-known volcanoes:

• Mauna Loa (Hawaii): Both produce extensive lava flows, but Bárðarbunga’s setting beneath ice creates additional flood hazards.

• Mount Pinatubo (Philippines): Pinatubo’s explosive eruption (1991) was different in style, yet both had far-reaching atmospheric impacts.

• Laki (Iceland): Like Bárðarbunga, Laki’s eruptions released massive amounts of lava and gas, altering climate and ecosystems.

• Mount St. Helens (USA): St. Helens’ 1980 eruption (VEI 5) was devastating, but Bárðarbunga’s 1477 eruption reached VEI 6, making it even more powerful.

A Volcano Under Watch

Today, Bárðarbunga remains closely monitored by Icelandic scientists. Its remote location under Vatnajökull means it poses limited direct risk to towns, but its scale and history make it one of the most important volcanoes in the country.

With past eruptions ranking among the largest in human history, Bárðarbunga serves as a reminder of Iceland’s dynamic geology and why the country remains a focal point for volcanology worldwide.

Frequently Asked Questions About Bárðarbunga Volcano

Where is Bárðarbunga volcano?

Bárðarbunga lies beneath Vatnajökull, Europe’s largest glacier, in Iceland’s remote central highlands. It is part of the extensive Bárðarbunga–Veiðivötn volcanic system.

What type of volcano is Bárðarbunga?

Bárðarbunga is a subglacial stratovolcano with a large, ice-filled caldera. Its volcanic system can produce both flowing lava and powerful explosive eruptions.

How large is the Bárðarbunga volcanic system?

The Bárðarbunga–Veiðivötn system extends for more than 190 kilometres across Iceland. Its central caldera covers approximately 70 square kilometres and reaches depths of around 850 metres.

How tall is Bárðarbunga?

Bárðarbunga rises approximately 2,009 metres above sea level, making it Iceland’s second-highest mountain after Hvannadalshnjúkur.

Why is Bárðarbunga so volcanically active?

Bárðarbunga lies near the boundary between the North American and Eurasian tectonic plates and above the Icelandic hotspot. This combination supplies the volcanic system with magma and contributes to its remarkable activity.

Does Bárðarbunga produce explosive or effusive eruptions?

It can produce both. Effusive eruptions create extensive lava fields, while explosive eruptions eject ash and tephra. Eruptions beneath the glacier may also generate dangerous glacial outburst floods.

What was the largest eruption associated with Bárðarbunga?

The Veiðivötn eruption of 1477 is considered Iceland’s largest known explosive eruption. It reached an estimated Volcanic Explosivity Index of VEI 6 and spread tephra across a vast area.

What was the Þjórsá Lava eruption?

Around 6600 BC, the Bárðarbunga volcanic system produced the Þjórsá Lava, which covered approximately 950 square kilometres. It is considered the largest known lava flow on Earth from the Holocene epoch.

When did Bárðarbunga last erupt?

Bárðarbunga’s most recent eruption began in August 2014 and ended in February 2015. Lava emerged from the Holuhraun fissure north of the volcano’s main caldera.

What happened during the 2014–2015 Holuhraun eruption?

The eruption produced approximately 1.6 cubic kilometres of lava and created a new lava field covering about 85 square kilometres. It was Iceland’s largest lava-producing eruption since Laki in 1783–1784.

How many earthquakes occurred during the Holuhraun eruption?

More than 30,000 earthquakes were recorded during the event. This intense seismic activity reflected magma travelling underground from Bárðarbunga toward the Holuhraun fissure.

Did Bárðarbunga’s caldera collapse during the eruption?

Yes. As magma left the underground reservoir, the floor of Bárðarbunga’s caldera subsided by as much as 65 metres. This was one of the most significant caldera-collapse events observed with modern scientific instruments.

Did the Holuhraun eruption affect air quality?

Yes. The eruption released enormous quantities of sulphur dioxide, reducing air quality across parts of Iceland. Volcanic pollution was also detected in mainland Europe.

What is a jökulhlaup, and could Bárðarbunga cause one?

A jökulhlaup is a sudden glacial outburst flood. Because Bárðarbunga lies beneath Vatnajökull, an eruption could rapidly melt ice and release large volumes of water and sediment into surrounding river systems.

What warning signs can appear before a Bárðarbunga eruption?

Possible warning signs include earthquake swarms, rising or sinking ground, changes in the glacier and increased volcanic-gas emissions. Scientists assess several signals together to determine whether magma may be moving.

How do scientists monitor Bárðarbunga?

Scientists use seismographs to detect earthquakes, GPS instruments to measure ground movement and satellites to observe changes in the glacier and landscape. They also monitor gas emissions, ice melting and possible glacial flooding.

Is Bárðarbunga dangerous to visitors?

Bárðarbunga’s remote location means it presents limited direct risk to towns and most travellers. However, eruptions may create lava, floods, volcanic gases and poor air quality. Visitors should always follow official guidance and respect closures.

Can I visit Bárðarbunga?

Bárðarbunga lies in an isolated and challenging part of the Icelandic highlands beneath Vatnajökull. Access depends on weather, road and safety conditions and should only be attempted with suitable preparation and guidance.

How does Bárðarbunga compare with other famous volcanoes?

Like Mauna Loa and Laki, Bárðarbunga can produce enormous lava flows. It is also capable of major explosive events, while its location beneath a glacier adds the distinctive danger of sudden glacial floods.

Can I experience real molten lava in Iceland?

Yes. At Lava Show in Reykjavík and Vík, you can safely watch real molten lava flow just metres away, feel its intense heat and hear it crackle as it cools. It brings the volcanic forces that created landscapes such as Holuhraun vividly to life.

Experience Real Molten Lava

The Bárðarbunga eruption was one of the most extraordinary volcanic events in Iceland's history, producing vast lava fields and reminding the world of the immense power hidden beneath the island. While witnessing an eruption like Bárðarbunga is incredibly rare, Lava Show lets you safely experience real molten lava flowing just metres away. It's a unique opportunity to see, hear and feel the volcanic forces that continue to shape Iceland.

Plan your visit:

• Experience Lava Show Reykjavík – Watch real molten lava flow in Iceland's capital.

• Experience Lava Show Vík – Experience the world's only live lava show on Iceland's South Coast.