Eyjafjallajökull Volcano and Glacier

Eyjafjallajökull is a stratovolcano, also called a composite volcano, in South Iceland, with an ice cap filling its summit caldera. Its name means "glacier of the island mountains," and that ice shaped the opening days of the 2010 eruption: meltwater flash-boiled against rising magma and shattered it into fine ash, which winds carried over Europe, grounding about 100,000 flights. Roughly a 2-hour drive from Reykjavík and visible from parts of the Ring Road, Eyjafjallajökull is one of Iceland's best-known volcanoes.

Eyjafjallajökull is a composite volcano, formed through many separate eruptions. Lava, ash, and tephra, the rock and volcanic glass thrown out during eruptions, built up over time to create the mountain we see today.

Stratovolcanoes can erupt violently because their magma is thicker and gassier than a shield volcano's thin, fluid lava. As that magma rises, the gas expands, and pressure builds until it's released in an eruption. Eyjafjallajökull's magma is basaltic-andesite, a composition of basalt and andesite. That thick, layered mix produces both lava flows and large amounts of ash.

Eyjafjallajökull's eruptions have produced a wide range of magma, from fluid basalt to thick, silica-rich rhyolite. The two phases of 2010 showed the difference: the Fimmvörðuháls fissures poured out fluid lava, while the magma that reached the summit was more viscous and more explosive.

The volcanic system extends east to west for about 25 km (15.5 mi) and is roughly 15 km (9.3 mi) wide. Beneath the mountain, researchers have identified several levels of magma storage and movement, from shallow depths of around 4 to 6 km (2.5 to 3.7 mi) to deeper levels of about 19 to 24 km (11.8 to 14.9 mi). Eyjafjallajökull lies in the Eastern Volcanic Zone, roughly 25 km (15.5 mi) west of Katla, part of the wider chain linked to the Mid-Atlantic Ridge, where the North American and Eurasian plates pull apart.

Yes, Eyjafjallajökull is still active, although it’s not erupting at present. Its known eruptions have been separated by long, irregular quiet periods, including the possible eruption around 920, and then documented ones between 1612 and 1613, 1821 to 1823, and 2010. Katla, its neighboring volcano, has been much more active historically, with an average interval of around 50 years between eruptions since Iceland’s settlement.

Eyjafjallajökull will likely erupt again eventually, but no one can say when. For now, there’s no reason to plan an Iceland trip around an eruption. The Icelandic Met Office monitors Eyjafjallajökull using seismic and GPS data, helping experts spot any signs of renewed unrest.

The 2010 Eyjafjallajökull eruption grounded flights because volcanic ash and jet engines don't mix. The glassy particles can melt inside a running engine and build up on its internal parts, so aviation authorities closed airspace wherever the ash was forecast to drift. Around 100,000 flights were canceled, making it one of the biggest disruptions to European air travel in modern times.

The eruption unfolded in two stages. A smaller, mainly effusive phase began at Fimmvörðuháls on March 20, where lava flowed from fissures for 23 days before activity stopped on April 12. On April 14, the eruption shifted to the ice-covered summit crater. It was strongly explosive for the first few days, quieter through late April as lava flowed north, then explosive again from early May, peaking in mid-May. The last sustained activity was recorded on May 22, 2010, though small explosions flared again in early June.

The ice cap explains why the ash was so fine in those first days. When rising magma met meltwater beneath the summit, the water flashed into steam and shattered the molten rock into tiny, glassy particles. In samples from that phase, around 35 to 50% of the fragments were finer than 0.063 mm (0.0025 in), small enough to stay in the atmosphere and travel long distances on high-altitude winds. Those winds carried the ash south and east toward European air routes.

The meltwater effect didn't last. From about April 18, the explosions were driven by the magma's own gas and the ash was much coarser, yet the May phase still sent ash high into the atmosphere. The ice explains the extremely fine ash of the opening days, not why the eruption as a whole produced so much of it.

The name breaks into three parts: eyja (islands), fjalla (mountains), and jökull (glacier). Put together, Eyjafjallajökull means “glacier of the island mountains.” Saying it takes a little practice. 

Try it one syllable at a time: AY-ya-FYAT-la-YO-kutl. The double ll in fjalla and jökull sounds closer to tl than a regular English l.

The lowland between Eyjafjallajökull and the coast is called Landeyjar, meaning "land islands." One local story says that glacial floods, known as jökulhlaups, once poured down from the volcano's ice cap and split the plain into scattered patches surrounded by water. Farmers reportedly rowed between these small islands until the flood drained away, and the name stuck.

Eyjafjallajökull is located in South Iceland, between Skógafoss waterfall and the Mýrdalsjökull ice cap. On a clear day, you can see the mountain from Route 1, Iceland's Ring Road, as you travel along the South Coast. To reach Eyjafjallajökull from Reykjavík, follow the Ring Road east toward the waterfall. The drive is about 147 km (91 mi) and usually takes up to 2 hours in good conditions.

You can’t drive up Eyjafjallajökull itself, but nearby trailheads give you access to the surrounding landscape. Gígjökull and Steinholtsjökull are two well-known outlet glaciers flowing down the mountain’s northern side. Gígjökull drains from the summit caldera, while Steinholtsjökull lies in the next valley to the east.

For one of the best roadside views, stop at the designated viewpoint at the historic farm Þorvaldseyri, just off the Ring Road. Its information panels show photographs from the 2010 eruption, and the mountain rises directly above the surrounding farmland. You’ll also get broad views of Eyjafjallajökull on the stretch of Route 1 between Seljalandsfoss and Skógafoss. Be sure to stop only at marked pullouts or parking areas, not on the road.

Yes, there are two main ways to hike Eyjafjallajökull: the Fimmvörðuháls trail, which passes the craters formed in 2010, or a guided hike onto the glacier itself. The first follows marked hiking trails between Þórsmörk (Thor’s Valley) and the small village Skógar. The second involves glacier travel and requires a qualified guide.

The shorter Fimmvörðuháls hike begins in Þórsmörk valley and climbs through the 2010 lava fields to Magni and Móði. This 14 km (8.7 mi) route returns along the same path and takes a full day with transfers from Reykjavík.

For the complete trail, start at Skógar, cross the pass, and descend into the valley. The 25 km (15.5 mi) route can be completed in one long day or split over two days with an overnight stay at Baldvinsskáli mountain hut.

The trail is usually accessible from late June to mid-September, although the exact dates depend on snow and weather conditions. It’s a demanding hike with around 1,000 m (3,281 ft) of ascent, and conditions can change quickly near the pass. Look up the forecast and trail conditions before setting out.

Hiking Eyjafjallajökull’s glacier is the harder option and should only be done with a qualified guide. The route is challenging, with crevasses, uneven ice, and changing conditions that require ropes, crampons, and glacier safety equipment. The 2010 eruption melted ice within the summit caldera and along Gígjökull, reshaping parts of the glacier and the terrain below it.

For a different way to experience Iceland’s glaciers, guided glacier hiking tours take you onto the ice to explore crevasses, ridges, and meltwater channels up close.

Iceland is often called the Land of Fire and Ice, and this part of the South Coast makes the contrast easy to see. Glaciers and active volcanoes shape the landscape here, including Katla and Hekla, two of the best-known volcanoes near Eyjafjallajökull. Katla lies beneath an ice cap, while Hekla rises above open farmland, showing how varied Iceland’s volcanoes can be within one region.

The Katla volcano is a stratovolcano beneath the Mýrdalsjökull ice cap, and its last confirmed eruption was in 1918. The eruption lasted about 23 days, sent an ash plume up to 14 km (8.7 mi) high, and caused glacial floods that carried ash, tephra, and rock to the sea. The deposits temporarily extended parts of the coastline by around 3 to 4 km (1.9 to 2.5 mi).

Katla has erupted alongside Eyjafjallajökull twice: together in 1612, then again shortly after the 1821 to 1823 eruption. However, Katla did not erupt in 2010. Icelandic authorities monitor the area for earthquakes, ground movement, and changes in water conditions, while Vík and nearby communities have evacuation plans in place.

Known as the gateway to hell, the Hekla volcano was long Iceland’s most famous volcano. The first recorded eruption was in 1104, and the most recent was in 2000. Hekla rises to 1,490 m (4,888 ft) above the surrounding farmland and is visible from parts of the South Coast on clear days. Its volcanic system includes a fissure swarm about 60 km (37 mi) long.

These waterfalls, glacier valleys, and volcanic craters are some of the most rewarding attractions on Iceland’s South Coast, all within easy reach of Eyjafjallajökull.

• Seljalandsfoss: A 60 m (197 ft) waterfall where a path leads behind the falling water. Wear waterproof layers, especially on windy days, as spray reaches the trail.
• Gljúfrabúi: Just a short walk from Seljalandsfoss, this smaller waterfall is partly hidden inside a narrow cleft. Step through the opening in the rock walls to see it fall into an enclosed pool.
• Skógafoss: This 60 m (197 ft) waterfall is 25 m (82 ft) wide and is just off the Ring Road at the foot of Eyjafjallajökull. The Fimmvörðuháls trail begins here and leads toward Magni and Móði.
• Magni and Móði: These two craters formed during the first stage of the 2010 eruption and were named after Thor’s sons in Norse mythology. Reaching them on the Fimmvörðuháls trail is one of the best things to do near Skógafoss if you want to continue beyond the waterfall.
• Þórsmörk: Also known as Thor’s Valley, this nature reserve lies between Eyjafjallajökull, Mýrdalsjökull, and Tindfjallajökull. You reach it via Road F249, which includes river crossings, so most visitors arrive by highland bus or with an experienced driver in a suitable vehicle.
• Gígjökull: This outlet glacier was swept away by meltwater floods during the 2010 eruption. Its glacial lagoon disappeared beneath volcanic sediment within a day of the eruption, leaving an outwash plain where older photographs show water.
• Sólheimajökull: This outlet glacier flows from Mýrdalsjökull and is reached from Road 221, just off the Ring Road. It’s one of the more accessible places on the South Coast for guided glacier hikes and ice climbing.