[News Terms] Unsettling 'Boundary of the Plate'... Another Volcanic Eruption in Iceland

A volcano has erupted again in Iceland. This is the fifth volcanic eruption in the region since December last year. The most recent eruption occurred on March 16. The Icelandic government has warned of the possibility of a volcanic eruption, noting that frequent uplift in the area indicates magma accumulation underground.

On the 29th (local time), a volcanic eruption began near Sundhnukagigar north of Grindavik in southwestern Iceland. [Image source=AP Yonhap News]

The active volcanic activity in Iceland is due to its geographical location at the 'plate boundary' where the tectonic plate and the Eurasian Plate are diverging. The plate boundary literally refers to the region that separates two different tectonic plates. The Earth's crust is mainly composed of seven large plates: the North American Plate, South American Plate, African Plate, Eurasian Plate, Australian Plate, Antarctic Plate, and Pacific Plate, along with medium-sized plates such as the Caribbean Plate, Nazca Plate, Philippine Plate, Arabian Plate, Cocos Plate, and Scotia Plate. These plates move gradually, and at the plate boundaries, where plates moving in different directions and speeds meet, various crustal movements occur. The most representative crustal movements are volcanic eruptions and earthquakes.

Plate boundaries are classified into convergent boundaries, divergent boundaries, and transform boundaries according to the relative movement of the plates. Among these, convergent boundaries occur when plates face each other and collide or when one plate overtakes another from behind, which can be broadly divided into collision type and subduction type. The collision type refers to crustal deformation caused by the collision of continental plates pushing upward, with the Himalayas being a representative example. The subduction type occurs when a continental plate and an oceanic plate collide, and the oceanic plate is forced beneath the continental plate, causing earthquakes or magma formation that leads to volcanic activity. The Japan Trench, Japanese archipelago, and Andes Mountains are examples of subduction zones.

Divergent boundaries occur where plates move apart and retreat. At divergent boundaries, earthquakes occur as plates split, or volcanic activity occurs as magma is expelled due to mantle convection upwelling. Volcanic activity at divergent boundaries tends to be less destructive than at convergent boundaries and involves the eruption of magma with lower viscosity.

At transform boundaries, where plates slide past each other, earthquakes are frequent, but volcanic activity is rare.

Meanwhile, according to foreign media on the 29th, at 12:46 PM local time in Iceland, an eruption began near Sundnukagigar north of Grindavik in the southwest, producing lava fountains reaching 50 meters high. Lava erupted from a 3.4 km long fissure, and the volcanic plume reached an altitude of about 3.5 km. The Icelandic Meteorological Office explained that the volume of lava was very large, estimated at 1500 to 2000 cubic meters per second.