Where are volcanoes on Earth?
The vast majority of volcanoes on Earth are concentrated along the boundaries of tectonic plates - subduction zones and mid-oceanic ridges. Subduction zones are areas where one tectonic plate moves under another plate, sinking into the Earth's mantle (a zone beneath the crust). This process creates a lot of energy, resulting in partial melting of the mantle and forcing magma (molten rock) to rise towards the surface.
In contrast, mid-oceanic ridges are areas where two tectonic plates are slowly separating causing the uplift of seafloor. This process heats up the magma in the Earth's mantle beneath and causes it to rise and extrude, creating new oceanic crust.
Some volcanoes have a different origin - they are called to be born on top of so called 'hot spots' that are outside of subduction zones and mid-oceanic ridges. It is believed that the Earth's mantle at the hot spot is much hotter than elsewhere creating 'mantle plumes' where hot magma rises from deep underneath the tectonic plate to the surface. Hot spots exist underneath either continental plates or oceanic plates, and can be away from plate boundaries.
The Pacific Ring of Fire
Image curtesy of U.S. Geological Survey
Photograph by therealbrute
The Pacific Ring of Fire marks the Earth's tectonically busiest areas located at the subduction zones around the Pacific Ocean. These areas are home to over one thousand volcanoes, many of them active, and also where large numbers of earthquakes.
Starting from the far north and going clockwise the Ring of Fire includes the following major volcanic areas:
- the Aleutian Islands and Alaska, home to volcanoes such as Mt. Spurr, Redoubt, Novarupta, Augustine, Pavlof or Kanaga,
- Cascade Volcanic Arc near the US west coast, including Mt. St. Helens, Mt. Rainier, Lassen Peak and Mt. Shasta,
- Mexico with a number of volcanoes, including Fuego de Colima, one of Central America's most active volcanoes, famous Popocatepetl near Mexico City, or Pico de Orizaba, the country's highest mountain,
- Central America; most volcanoes here are located in Guatemala (Santa Maria, Pacaya, Fuego), El Salvador (Izalco), Nicaragua (Cerro Negro, Masaya) and Costa Rica (Arenal, Irazu, Poas, Turrialba, Ricon de la Vieja),
- South American Andes with Nevado del Ruiz and Galeras in Colombia, Cotopaxi and Reventador in Ecuador, Llullaillaco, Villarrica, Calbuco and Monte Burney in Chile,
- New Zealand; most famous volcanoes there are Taupo, Ngauruhoe and Ruapehu
- Tonga-Kermadec island chain, Samoa and the New Hebrides; probably the most interesting place here is the Tanna Island, that belongs to Vanuatu nation, with the active Yasur volcano,
- Papua New Guinea with its Rabaul volcanoes,
- Indonesia with some of the world's most famous volcanoes: Krakatau and Tambora as well as Merapi, Agung, Semeru or Galunggung; Indonesia is home to 76 volcanoes that have been active in historic times,
- Philippines, home to several dangerous volcanoes like Pinatubo, Taal or Mayon,
- Japan with the famous Mt. Fuji and other frequently active volcanoes like Unzen, Sakurajima or Shinmoedake that violently erupted in January 2011,
- Kurile Islands and Kamchatka Peninsula; some of the major volcanoes in this area are Bezimianny, Karymsky, Kluchevskoy, Tolbachik, Avachinski or Koryak.
Many of the places noted above are very attractive travel destinations and excellent for volcano tours. Most interesting for the travelers from North America are certainly the volcanoes in the continental US, Mexico and Costa Rica, due to short distance and good tourism infrastructure. Enthusiasts of volcano tours from Australia will probably find New Zealand or Indonesia the most convenient places to go to, with Vanuatu being a very interesting destination too, mostly for the more adventurous types. As for European residents - they don't have to look very far - Italy, Iceland or Greece are beautiful and perfect destinations for volcano explorations.
Volcanoes along the mid-Atlantic Ridge
The chain of volcanic islands on the mid-Atlantic ridge extends from island of Jan Mayen in far north through Iceland, Azores islands, the Canary Islands, Cape Verde Islands, the island of St. Helena, Gough Island and to the Bouvet Island in the south. From the traveler's point of view, the most interesting destinations belonging to this chain are Iceland, Azores, Canary Islands and Cape Verde Islands, all of them very popular with visitors.
Iceland is world's most volcanic country and home to about 130 volcanoes, with more than 20 of them active. The best known Iceland volcanoes are Hekla, Krafla, Eldefell and Grímsvötn. Worth mentioning is also the Eyjafjallajökull volcano - although much smaller and less dangerous, but mighty enough to have caused havoc in the air travel business in Europe for several weeks in spring 2010. Iceland is a quite unique place, not only very geologically active and perfect destination for volcano tours, but also exceptionally beautiful with it's spectacular glaciers, geysers, lakes or waterfalls.
Portuguese Azores are a popular vacation destination and have several historically active volcanoes, some of them being submarine volcanoes. The best known are: Auga de Pau, Capelinhos or Monaco Bank (submarine). South-east of Azores are Spanish Canary Islands - also a prime tourist destination (much more crowded and commercial compared to Azores) - with El Teide volcano on Tenerife Island being Spain's highest point. Other famous volcano there is Teneguia, that last erupted in 1971. The highlight of the volcanic islands of Cape Verde is the Fogo volcano that last erupted in 1995.
Photo taken by Brian Snelson during an airplane volcano tour
Hawaiian islands are the effect of the volcanic activity created by a 'hot spot' in the middle of the Pacific Ocean. They were slowly built up from the bottom of the ocean by repeated eruptions which process continues to this day. A new island, Loihi, is currently being built by underwater volcanic eruptions and it will likely become the most active of Hawaiian volcanoes in a few centuries.
Currently the most active Hawaiian volcanoes are Kilauea, Mauna Loa and Haleakala (East Maui). Kilauea volcano is probably the best example of the expanding volcano tourism. Mild eruptions of Kilauea started in 1983 and still continue, giving visitors a great chance to witness magnificent spectacles of lava and fire. Kilauea is also the most accessible (and relatively safe to watch) volcano, adding to the popularity of volcano tours.
Volcanoes in the Mediterranean
The volcanoes of the Mediterranean basin are situated along the subduction zones between the African plate and the Eurasian plate. These subduction zones created two volcanic arcs: the Hellenic (or Aegean) Arc and the Calabrian Arc. The Hellenic Arc comprises several Greek volcanic islands located on the Aegean Sea and includes the famous Santorini with Nea Kameni volcano as well as Nisiros, Milos, Kos, Yali and Methana.
The Calabrian Arc is home to Italian volcanoes, situated along the edge of the Tyrrhenian Sea. The most famous and active volcanoes of this region are Mt. Vesuvius near Naples, Mt. Etna in Sicily, Stromboli and Vulcano. The Stromboli volcano has been active for centuries and is one of the best volcanoes to visit for someone who wants to be sure to see spectacular eruptions.
Thanks to the large number of prime sightseeing destinations that are close by, the weather, well developed tourism infrastructure as well as history and culture of the nations, volcano tours in Greece and Italy have become more and more popular, attracting thousands of travelers.
Most of African volcanoes are concentrated along the East Africa Rift Valley that extends from the Red Sea in Ethiopia to Tanzania. In the northern part of the valley the most famous and very active volcano is Erta Ale in Ethiopia. The volcano has delighted those few who came to visit with one or two lava lakes in its crater. Unfortunately due to political situation in this part of the world, volcano torus there are considered dangerous for tourists (and not because of the volcano itself), so the volcano hasn't have to many international visitors so far.
More accessible volcanoes are located south - Mt. Kenya in Kenlya (no longer active), Mt. Kilimanjaro in Tanzania (Africa's highest point), Ol Doinyo Lengai in Tanzania or the huge caldera of Ngorongoro, also in Tanzania (visited mostly for its wildlife). The west of the Rift Valley is home to two very active volcanoes, located in the Democratic Republic of the Congo (formerly Zaire): Nyiragongo and Nyamuragira.
The highlight of West Africa's volcanoes is Mt. Cameroon, situated at the coast and most active in the western part of the continent; the nearby Oku Volcanic Field is also very known, mostly due to the disaster in 1986 that killed at least 1,700 people who were poisoned by toxic gases released from the bottom of Lake Nyos.
A very interesting destination for volcano torus is the French island of Réunion, located east of Africa, on the Indian Ocean. The Piton de La Fournaise volcano is currently one of the world's most active volcanoes that has had mild eruptions for the past few years and is definitely worth exploring.
The Yellowstone Caldera, sometimes called the Yellowstone Supervolcano, is one of the best known and most visited volcanic areas in the world. The location of the volcano is far from the boundaries of tectonic plates so it is believed that the Yellowstone Caldera was created by a hot spot underneath the Earth's crust. Most of the activity in the caldera is currently in form of geysers and hot springs, but some scientists indicate that the volcano may wake up in the future with eruptions on a very large scale.