Volcanoes

This category includes most unusual and interesting volcanoes of the world.

What are volcanoes?

Over the last 10,000 years in some 1,500 places around the Earth through the crust of the planet has been emitted lava, ash, and gases from the mantle of Earth. Each of these places could be considered to be an active volcano. Every year some 50 – 70 volcanoes are erupting, at any moment there are some 20 – 30 eruptions ongoing.

Best known and visually most impressive are stratovolcanoes – tall and conical mountains with a vent that opens in the summit. But there are other types of volcanoes as well, such as shield volcanoes and fissure vents – linear rows of smaller volcanoes or even open fissures. Not always it is easy to decide whether the diverse closely located volcanic features are parts of a single volcano or separate volcanoes.

What defines "unusual volcanoes"?

The mission of Wondermondo is to describe all the unusual places ("wonders") around the world. Each of the 1,500 active volcanoes and also some of the inactive ones are such unusual places. But, as always in life, some are more unusual than others.

The most unusual volcanoes can have the following characteristics:

• Record size or other superlatives;
• Unusual volcanic and other geological processes;
• Unusual geochemistry and characteristics which are linked to it;
• Unusual shape.

Volcano records

The tallest active volcano on Earth (above sea level) is the Ojos del Salado (Chile), 6,891 m tall. It contains also the world’s highest-located lake at a height of 6,390 m.

The world’s tallest volcano as measured from its base is Mauna Kea (United States, Hawaii) which rises from the ocean floor 10,203 m tall. This is the tallest mountain in the world.

Chimborazo volcano (Ecuador) holds an unusual record – this 6,268 m tall mountain is the farthest point on the Earth’s surface from the center of Earth.

The deepest known volcano is located in Cayman Trough, Caribbean. These deep-sea vents are located at the depth of some 5,000 m.

World’s biggest volcano – Tamu Massif under the waves of north-west Pacific – falls outside the scope of Wondermondo as its area exceeds 500 km² multiple times – it is some 311,000 km² large!

The oldest still-active volcano in the world is the giant Mount Cameroon (Cameroon). It has managed to have the stamina (e.g. reservoir of magma under it) for the last 30 million years at least.

Only a few volcanoes in the world have lava lakes and the most persistent lava lake is in Erta Ale volcano (Ethiopia) – this volcano holds a lake of liquid stone since 1906 at least.

The largest intact volcanic caldera is Ngorongoro Crater (Tanzania) – an amazing structure with an area of 260 km² and surrounded by up to 610 m tall walls and steeps.

The largest lava lake was seen in Masaya Volcano (Nicaragua) in 1670 – it was approximately 1 km wide.

Unusual processes

There are few volcanoes in the world which are constantly active – constantly erupting. This offers predictable and magnificent sights. Among the most active ones can be mentioned Etna and Stromboli (Italy) which are erupting almost constantly for millennia, Kīlauea (Hawaiian Islands), Mount Yasur (Vanuatu), Piton de la Fournaise (Reunion), and others.

In most cases volcanoes are erupting from a single vent – there is a mountain with the eruption at its summit. But there are times when Earth seems to open and from a long crack starts to flow lava. One such eruption took place in Iceland in 1783 – 1784, when simultaneously erupted a chain of 130 craters – Laki fissure vent.

Active volcanoes are dynamic and often – changing. Some of these changes and processes are very unusual and impressive. Thus, for example, there are volcanoes which are rising from the sea: there appears a new island – volcano… it is washed away by the ocean waves and rises again and then – again… Some examples are Home Reef (Tonga), and Kavachi (Solomon Islands). Often such submarine volcano manages to rise successfully and new island persists – such as Surtsey (Iceland) which rose from 1963 to 1967. Curtis Island (Kermadec Islands) has risen earlier and continues to rise quickly, with almost daily earthquakes. And there are also volcanoes that are rising and soon they might reach the surface of the ocean (Kick-’em-Jenny in Grenada).

A natural wonder, albeit often very unpleasant is volcanoes that suddenly rise from a flat field. Such recent surprises have been Parícutin (Mexico) and Shōwa-shinzan (Japan).

During the eruption one can witness liquid rocks – lava. But in very rare cases there form lava lakes which exist for a longer time. Currently, these volcanoes contain lava lakes:

• Erta Ale (Ethiopia);
• Masaya volcano (Nicaragua) – intermittent, has been up to 1 km wide in 1670;
• Mount Erebus (Antarctica);
• Mount Michael (South Sandwich Islands).
• Mount Nyiragongo (Congo DR) – at some moments this is the largest lava lake in the world;
• Mount Nyamuragira (Congo DR) – intermittent but with a possibility that it will become a permanent lake now;
• Villarrica volcano (Chile) – intermittent.

There existed or could exist some more lava lakes:

• Benbow Crater and Mbwelesu Crater (Vanuatu, Ambrym Island) – both were nearly permanent and spectacular until disappeared;
• Mawson Peak of Big Ben (Heard Islands);
• Halemaumau Crater with a lava lake, Kilauea (Hawaiian Islands), often also in the nearby Puʻu ʻŌʻō crater. In 2019 there is no lava lake in any of these craters;
• Mount Belinda (South Sandwich Islands);

Some volcanoes emit poisonous and also rammish gases which affect wide environs – this is a kind of frequent chemical attack. For example, Mount Asphyxia (South Sandwich Islands) frequently emits suffocating gases which together with the huge amount of penguin guano on the island can make the stay on Zavodovski Island unbearable. Large "field of acid" has been formed by Benbow and Marum volcanoes (Vanuatu), Masaya (Nicaragua), Poás volcano (Costa Rica).

Unusual geochemistry

Volcanoes exhibit interesting chemical properties rather frequently.

In rather many cases volcanic craters contain colourful, acid solutions. Such lakes of acid are found in the craters of Ebeko (Russia, Kuril Islands), Maly Semiachik (Russia, Kamchatka), and Mount Douglas (United States, Alaska). Nakadake Crater Lake (Japan) is almost pure acid, with pH ranging from 0.5 to 1.7, similar acidity is in Ijen Caldera (Indonesia) but Laguna Caliente in Poás volcano (Costa Rica) sometimes reaches even the nearly impossible 0.0 pH. As if this is not enough, phreatic eruptions may eject this acid up to 1 kilometer high.

These lakes may have bright, unusual colors. These colors change over time, turning from white into bright blue or green. Very unusual are Kelimutu crater lakes (Indonesia) – three closely located lakes, where each of which has a different color – from bright red to green and blue.

Even volcanic flames sometimes have unusual colors. Thus the burning sulphuric gases in Ijen Caldera (Indonesia) at the night have an impressive blue color.

Sometimes whole volcano consists of unusual substance. Such unique volcanoes are Ol Doinyo Lengai and Kerimasi in Tanzania – both are erupting very unusual natrocarbonatite lava which soon turns bright white as snow.

Below the waters of oceans are located very weird volcanoes. Thus Daikoku Sulphur Cauldron (Northern Mariana Islands) contains a unique pool of liquid sulfur, and NW Eifuku Champagne Vent (Northern Mariana Islands) emits almost pure liquid carbon dioxide.

Unusual shape

Some volcanic formations have very unusual shape. For example, the Molokini crater (Hawaii) is just a perfect, green crescent rising from the blue ocean. Somewhat similar, but on the land and even more impressive is Fort Rock (United States, Oregon) which reminds ruins of a giant fortress. Suswa Volcano (Kenya) has a unique double crater that looks like a deep-pressed ring around its summit.

Many volcanoes are well known thanks to their perfect, symmetric shape. It is hard to say which one is the most symmetrical in the world but some of the most amazing ones are Mayon (Philippines), Mount Shishaldin (United States, Alaska) and the gorgeous Kronotsky (Russia, Kamchatka).

And many, many volcanoes are just beautiful in everything. Some are famous in the whole world (Mount Fuji in Japan), others are less known but not less gorgeous (Maelifell in Iceland).

Wondermondo has the following articles about volcanoes: