Iceland's Volcanic Landscape: A Living Laboratory of Plate Tectonics and Eruptions
Iceland is one of the most volcanically active locations outside tropical zones. Its geological character is defined by the Mid-Atlantic Ridge spreading zone meeting with a mantle hotspot, resulting in a unique combination of spreading and hotspot volcanism. The island has numerous active volcanic zones, including the Reykjanes Volcanic Belt (RVB), the Western Volcanic Zone (WVZ), the Mid Iceland Belt (MIB), the Eastern Volcanic Zone (EVZ), the Northern Volcanic Zone (NVZ), and smaller belts. Divergence tectonics at plate borders produces low-viscosity tholeiitic basaltic lava, resulting in broad lava fields and shield volcanoes, as opposed to steep cone-shaped stratovolcanoes observed in subduction zones.
Volcanic activity occurs beneath Vatnajökull, Europe's largest ice cap by volume. Iceland's glacier covers 7,500 square kilometres and is home to seven active volcanoes. Subglacial and marginal lakes are maintained by volcanism and geothermal heat, which can cause catastrophic jökulhlaups (glacial outburst floods). Vatnajökull has ice domes with an average thickness of 380 meters and a maximum thickness of 950 meters (3,120 feet). The glacier is home to Iceland's highest mountain, Hvannadalshnúkur (2,109.6 meters / 6,921 feet), located on its southern edge.
Recent volcanic activity reveals Iceland's ongoing geological dynamism. In October 2023, pressurised magma pushed through a fissure near Grindavík, causing earthquakes and ground deformation. This is similar to the Mid-Atlantic Ridge spreading, where plates separate, and the underlying mantle rises to fill the gap, causing melting at depth. Visitors to Thingvellir National Park can practically walk between the two diverging tectonic plates—the Eurasian and North American plates—and see topographic scars from the rift in long, linear valleys extending northeast. Iceland is a unique living laboratory for researching plate tectonics, hotspot volcanism, and magmatism. Research institutions around the world use Iceland's natural features to investigate fundamental Earth processes.
