Worldwide volcano guides 

Why are there volcanoes in Europe?

The main seismically active areas of Europe are associated with the active margin between Southern Europe and Africa. Africa is pushing northwards into Europe creating a collision zone. The Mediterranean is split into a number of microplates which form subduction zones,continental plate collision zones and conservative fault zones.As Africa has pushed northwards against Europe the floor of the Mediterranean has sunk into the mantle along a crack in the earths crust along subduction zones causing new magma to rise to the surface. Main areas of volcanism are in southern Italy and Greece. Earthquake activity occur from Turkey to Spain.

The volcanoes of the Mediterranean are explosive and potentially more dangerous to people. Vesuvius ( AD79) and Santorini both erupted suddenly and violently devastating their surrounding populations. These volcanoes are the classic cone and crater volcanoes with lots of ash.

Mt. Etna shows both types of volcanism and is one of Europes most dramatic and active volcanoes. It dominates the Eastern side of Sicilly with its snow capped summit.

The volcanoes of Iceland and the Canaries are due to an upwelling of rock from the earths interior called a mantle plume. This jet of hot rock erupts at the surface by punching hole through the crust above. Black basalt lava flows, fissures and cones shape the landscape.

Why are there volcanoes in North America?

The volcanic regions of North America inlcude the Cascades, The Aleutian Islands and Hawaii. West of the Rockies the volcanic activity is due to the westward movement of the Pacific plate meeting the eastward movement of the Pacific Plate. At present a subduction zone where the Juan da Fuca plate is being subducted beneath the North American plate is producing the volcanics of The Cascades including the infamous Mt.St.Helens. The Yellowstone Caldera is a product of a Hot Spot underneath the continental crust and is potentially one of the worlds most dangerous volcanoes.

Hawaii is the jewel in the crown of the worlds volcanoes. The result of a Hot Spot or mantle plume beneath the Pacific plate which punches a hole through the crust and erupts out lava from the earths interior. Kilauea on Big Island has put on a continuous show of lava flows for decades and it is still going pouring lava into the sea.

Why are there volcanoes in the Caribbean?

Volcanic activity in the Caribbean has created some of the most beautiful paridise islands in the world. During the 20th Century two of these islands were reminded of the destrucutive power of volcanoes. Montserrat and Martinique both had sleeping volcanoes which woke up dramatically.

The Antilles Volcanic Island Arc has created an archipelogo of tropical islands.As the North Atlantic plate has subducted benath the Caribbean plate magma has risen through the crust to puncture the plate above and create volcanic islands. Most of the eruptions would have been violent and included pyroclastic flows like on Montserrat.

In 1995 on the small British island of Montserrat the Soufriere Hills volcano started a series of dramatic eruptions which devasted the southern two thirds of the island.Dramatic pyroclastic flows swept down all sides of the volcano wiping out the tropical landscape and consuming the capital ,Plymouth.

In 1902 Mt.Pelee on the French Island of Martinique killed
30 000 people when a dramatic eruption swept through the town of St.Pierre.

Why are there volcanoes in New Zealand?

New Zealand is one of the most tectonically active countries in the world and sits astride the plate margin between the Australian plate and the Pacific plate. The majority of North Islands active volcanoes are witin the Taupo Volcanic Zone, an area of extension (down faulted graben) caused by the subduction of the Pacific plate beneath the Australian plate. The Pacific Plate is sinking beneath the Australian at a rate of 5cms/year.

The TVZ extends from the centre of North Island from Ruapehu to White Island in the Bay of Plenty and has been active for the last 1.6 million years. The zone is the result of extension and subsidence causing a back arc basin. As the crust thins magma from the mantle can well up, add in the subduction zone and New Zealands North Island is a volcanic wonderland. There is a mixture of volcanic activity types. Lake Taupo hides an enormous supervolcano, Ruapehu is an andesitic strato volcano and Tarawera effuses sticky rhyolite lava domes.

Unlike the North Island the South Island has no active volcanoes because here the plate boundary is not subduction but is a conservative or strike slip boundary where the the two plates side past each other. There are some remannts of old volcanoes such as the Otago and Banks peninsulars which were active 20 million years ago. Taupo, Rotorura and Ruapehu are the most accessible. White Island and Tarawera have more restricted but still possible with some cash.