Iceland is located on the Mid-Atlantic Ridge, which is technically the world’s longest mountain range resting on the floor of the Atlantic Ocean. This distinctive ridge separates the Eurasian and North American tectonic plates, marking a hotspot for seismic activity. Primarily, this ridge lies beneath the sea, extending from the north to the south of the Atlantic. Nonetheless, in the North Atlantic region, it soars above the ocean surface, forming the terrain of Iceland.
This unique geological trait shapes Iceland’s exceptional landscape characterized by geysers (hot springs), glaciers, mountains, volcanoes, and lava fields. Iceland hosts 33 active volcanoes, the highest number in Europe, earning it the nickname, ‘Land of Fire and Ice’. Among these, Eyjafjallajökull is well-known for its 2010 eruption that spewed out a significant ash cloud. Other notable volcanoes are Hekla, Grímsvötn, Hóluhraun, and Litli-Hrútur, belonging to the Fagradalsfjall system.
Vulnerable Volcano Regions Across the Globe
Volcanoes are situated worldwide, mainly along the peripheries of Tectonic Plates. Intraplate volcanoes are exceptions as they form from mantle hotspots.
The Circum-Pacific Belt or the Pacific “Ring of Fire” is an array of volcanoes and areas located on most of the Earth’s subduction zones with a high seismic activity – around the peripheries of the Pacific Ocean. This ring encompasses a total of 452 volcanoes, the majority of which are found on its western edge, extending from the Kamchatka Peninsula in Russia, through the islands of Japan and Southeast Asia, and reaching New Zealand.
The Mid-Continental Belt is a volcanic belt that stretches along the Alpine Mountain system of Europe and North America, through Asia Minor, Caucasia, Iran, Afghanistan, and Pakistan to the Himalayan Mountain system. This belt includes areas such as Tibet, the Pamir, Tien-Shan, Altai, and the mountains of China, Myanmar, and eastern Siberia. Volcanoes in this belt are found in the Alps Mountains, Mediterranean Sea (Stromboli, Vesuvius, Etna, etc.), Aegean Sea, Mt. Ararat (Turkey), Elburz, Hindu Kush, and Himalayas.
The Mid-Atlantic Ridge separates the North and South American Plate from the Eurasian and African Plate. Here, magma ascends through cracks and leaks onto the ocean floor, forming a long, thin undersea volcano. As it gets in contact with water, it cools down and solidifies, adding to the sideways-moving plates. This process over the divergent boundary has resulted in the creation of the world’s longest topographic feature – mid-oceanic ridges submerged beneath the oceans.
Approximately 5% of known volcanoes, not closely related to plate margins, are considered intraplate or “hot-spot” volcanoes. A hotspot is thought to be associated with the rising of a deep-mantle plume due to very slow convection of highly viscous material in Earth’s mantle. It can be represented by a single oceanic volcano or lines of volcanoes, like the Hawaiian-Emperor seamount chains.
A Snapshot of Volcano-Related Queries for the UPSC Civil Services Examination
In the Prelims section of the 2018 examination, examinees were asked whether the following statements about the Barren Island volcano were correct: The Barren Island volcano is an active volcano located in the Indian territory, lying about 140 km east of Great Nicobar, and last erupted in 1991, remaining inactive since then. The correct answer was that the Barren Island is India’s only active volcano, located in the Andaman and Nicobar Islands, and not 140 km from Great Nicobar as stated. Furthermore, this volcano has had a history of eruptions, the latest recorded in February 2016.
In the Mains section, the 2020 examination asked about the geophysical characteristics of the Circum-Pacific Zone. In the 2021 examination, candidates were asked to mention global volcanic eruptions that year and their impact on the regional environment.