The Apollo missions that brought back rock samples from the Moon enabled geologists to establish that the lunar circles, that are clearly visible from the Earth through a telescope, are basalt extrusions.
The presence of other volcanoes in the solar system was discovered by the Voyager 1 and 2 probes,
· including Mount Olympus on Mars, which is 24 km high and has a diameter of 500 km. It is the biggest volcano in the solar system;
Mount Olympus on Mars is the biggest known volcano in the solar system.
· Several extra-terrestrial eruptions were observed in March 1979 on lo, a satellite of Jupiter, in the form of sulphur plumes of between 70 and 280 km high;
· Signs of cryo-volcanism (cryo = ice) and geysers on Triton, Neptune's first satellite;
· In 1990, the Magellan probe and its airborne radar revealed that the surface of Venus displays numerous types of volcanic structures: drop shaped domes and giant shield volcanoes. In fact, nearly 140 volcanoes were counted that were more than 100 km wide, along with more than 800 structures of 20 to 100 km in diameter and several million small volcanoes.
For geo-astronomers, the "volcano" phenomenon is therefore the way in which a planet expels the excess heat contained at its core.
A few significant volcanic eruptions
Volcano Place Date of the eruption Number of casualties Direct and Indirect consequences
Crater Lake (Mt Mazama eruption) United States 4860 BP - 50 km3 of pyroclastic surges + lahars + tephras
El Chichon Mexico 1981 2,500 0,5 to 0,6 km3 of pyroclastic surges
Etria Sicily, Italy 1843 59 Lava flows 1979 9 Phreatic eruptions
Galung gung Indonesia 1822 4,000 Lahars
Hemaey Iceland 1973 Houses Destroyed, no casualties 0,11 km3 of tephras + lava flows
Kelud Indonesia 1919 5,110 0,04 km3 of mud
Kilauea United States (Hawaii) Quasi continuous eruptions Houses and roads destroyed, no casualties Liquid lava flows and fountains
Krakatau Indonesia 11 August 1883 36,400 $ATT$ (tidal waves of volcanic arlgin)
Mount Pélée Martinique 8 May 1902 29,000 Pyroclastic surges
Lake Nyos Cameroon 1986 1,746 Release of cartion dioxide
Lakagirar Iceland 1783 10,000 Toxic gases + 10 km of tephras on cultivated areas leading to famines
Lamington New Guinea 15 January 1951 3,000 10 km3 of pyroclastic surges + lahars
Maklan Indonesia 1760 2,000 Lahars
Merapi Indonesia 22 November 1994 64 Pyroclastic surges
Mt St Helens United States (Washington state) 18 May 1980 48 Violent directed blast + 3 km3 of pyroclastic surges + lahars
Nevado det Rulz Columbia 15 November 1985 25,000 Lahars
Paricutin Mexico 1943-1952 100 Viscous lava flows - famine
Pinatubo Philippines 12 June 1991 700 9 km3 of of pyroclastic surges and fallout + lahars
Santa-Maria Guatemala 1902 6,000 Pyroclastic surges + lahars
Santorini Greece 1500 BC Disappearance of the minoan civilisation 30 km3 of pyroclastic surges + tsunamis
Stromboli Eolian Is. (Italy) Eruption has been going on for 2000 years Less than 50 casualties in the 20th century Pyroclastic projections and fallout
Soufrière Guadeloupe 1976 No casualties Phreatle eruptions and ash fallout
Soufrière-Hill Montserrat 1996-1998 19 Pyroclastic surges
Soufrière Saint-Vincent 1902 1,565 Pyroclastic surges
Surtsey Iceland 14 November 1969 No casualties 11 km3 of ash fallout
Tambora Indonesia 10 April 1815 60,000 including 11,000 buried under tephras 150 km3 of pyroclastic surges + tsunamis + tephras + famines + $ATT$
Toba Indonesia 75000 BC - 1,000 km3 of pyroclastic surges + tsunemis + tephras
Unzen Japan 1792 15,200 Tsunamis + 15 km3 of pyroclastic surges
Vesuvius Italy 79 AD 3,000 ? 3 km3 of pyroclastic surges + lahars
Vesuvius Italy 1631 4,000 Pyroclastic surges + tephras
Vulcano Eolian Is. (Italy) 1888-1889 ? Pyroclastic surges + tephras
The highest volcano in the world is the Nevado Ojos de Salado in Chile; this sleeping volcano reaches a height of 6.885 m.
The smallest volcano is only 50 cm high; it was observed in August 1980 by one of the authors (Pierre Lavina) near the Krafla, in Iceland
