Bardarbunga

Geography & Climate

Bardarbunga is located in Iceland, within the Iceland Neovolcanic Rift Volcanic Province of the broader Atlantic Ocean Volcanic Regions. Situated at 64.63° N, 17.52° W in the Northern Hemisphere, the volcano lies within a subarctic climate zone. With a summit elevation of 2,000 meters above sea level, Bardarbunga is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Bardarbunga is situated along a rift zone, where tectonic plates are pulling apart. As the crust thins and fractures, magma rises to fill the gap, creating volcanic activity. Rift volcanism typically produces more fluid lava flows rather than explosive blasts, which means communities near Bardarbunga in Iceland generally face slower-moving hazards like lava flows and ground fissures rather than sudden pyroclastic events. However, rift volcanoes can still generate significant ash emissions and gas releases that affect local air quality. The dominant rock type is basalt / picro-basalt, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Bardarbunga has 55 recorded eruptions in the geological database, spanning from 7100 BCE to 2015 CE. The most powerful recorded event was a colossal eruption capable of affecting global climate for years in 1477 CE, reaching VEI 6 on the Volcanic Explosivity Index. Notable eruptions include 1717 CE (VEI 3), 1477 CE (VEI 6), 870 CE (VEI 4). With an average interval of roughly 166 years between eruptions over a span of 9,114 years, this is one of the more frequently active volcanoes in the database. This persistent activity suggests a robust and well-supplied magma system beneath the volcano. With eruptive activity as recently as 2015 CE, Bardarbunga remains an actively monitored volcano.

Significance

Bardarbunga has produced at least one eruption of VEI 6 or higher, placing it among the most powerful volcanic systems on Earth. Eruptions of this magnitude inject massive quantities of sulfur dioxide into the stratosphere, affecting global climate by lowering average temperatures for one to three years after the event. Its 55 recorded eruptions make it one of the most prolific volcanoes in the entire global volcanic record, reflecting an exceptionally persistent magma supply system that has sustained near-continuous eruptive activity over millennia. Given its recent activity, Bardarbunga is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

The large central volcano of Bárðarbunga lies beneath the NW part of the Vatnajökull icecap, NW of Grímsvötn volcano, and contains a subglacial 700-m-deep caldera. Related fissure systems include the Veidivötn and Trollagigar fissures, which extend about 100 km SW to near Torfajökull volcano and 50 km NE to near Askja volcano, respectively. Voluminous fissure eruptions, including one at Thjorsarhraun, which produced the largest known Holocene lava flow on Earth with a volume of more than 21 km3, have occurred throughout the Holocene into historical time from the Veidivötn fissure system. The last major eruption of Veidivötn, in 1477, also produced a large tephra deposit. The subglacial Loki-Fögrufjöll volcanic system to the SW is also part of the Bárðarbunga volcanic system and contains two subglacial ridges extending from the largely subglacial Hamarinn central volcano; the Loki ridge trends to the NE and the Fögrufjöll ridge to the SW. Jökulhlaups (glacier-outburst floods) from eruptions at Bárðarbunga potentially affect drainages in all directions.

— Smithsonian Institution, Global Volcanism Program