Volcanoes are found all over the world, forming primarily at the edges of tectonic plates but can also arise in “hot spots” like the one that created the Hawaiian Islands. In total, there are potentially a few 1,500 active volcanoes on Earth according to the US Geological Survey. From these, 51 are now in continuous rash state, the most recent in La Palma in the Canaries.
Many of these volcanoes are located on the “Ring of Fire” which is located all along the Pacific Rim. However, the greatest number of volcanoes are hidden from view underwater at the bottom of the ocean.
How are volcanoes created?
Volcanoes occur in specific places, either the product of tectonic plate activity or hot spots. They are the result of hot magma melting the rocky crust above and pushing its way to the surface. Once above the crust, the magma becomes lava which gradually builds up from the crack or vent in the crust forming a volcanic cone.
Most volcanoes, about sixty percent, are located near the boundaries between tectonic plates. These are plates of the earth’s crust that float on the softer, more fluid mantle that can move linearly with respect to each other, collide, or pull apart. The last two interactions present the greatest opportunity for volcanic eruptions. When the two plates separate, as in the Rift Valley in Africa or the Mid-Atlantic Ridge, volcanoes can emerge.
When two plates collide and one is thinner than the other, like an oceanic plate, it slides under the thicker and heavier continental plate in a process of subduction. The material in the oceanic plate melts when it is pushed down into the Earth. This molten material then rises to the surface causing volcanic eruptions. This is the process that is at the origin of the “Ring of Fire” encircling the Pacific Ocean where around 350 have been active in historical times.
Not all volcanoes are located at the boundaries of tectonic plates. As the tectonic plates move, parts of their interior may be located on “hot spots“or magma plumes, places where the crust rests on an area of the mantle that is thought to be warmer than the surrounding mantle. Widespread volcanic activity ensues as the magma plume melts and thins the rocky crust above. Examples are the Hawaiian Islands and the Yellowstone supervolcano, and more recently the eruption of La Palma in the Canaries.
Where are the most volcanoes?
The Pacific Rim is home to the Ring of fire contains the most volcanoes on Earth, but there is disagreement over whether to include those in the western Indonesian archipelago and those in Antarctica.
In 2017, researchers at the University of Edinburgh revealed 91 new volcanoes under the vast ice cap of Western antarctica. In addition to the 47 other known volcanoes, this made the Western Antarctic Rift System the densest volcanic region in the world.
Before that, the East African Rift, from the Red Sea to Mozambique, had the highest concentration of volcanoes.
The highest concentration of active volcanoes is in Russia Kamchatka Peninsula. Four volcanoes, Shiveluch, Bezymianny, Tolbachik, and Kizimen are only 110 miles apart. On January 11, 2013, they all erupted at the same time.
What is the most recent volcano?
In 1943, the land opened outside the village of Paricutín in west-central Mexico, and lava began to spit out. It wouldn’t stop for nine years bury Paricutín and nearby San Juan Parangaricutiro. The rash left behind a new volcanic cone measuring 1,475 feet (450 meters).