Explosive eruptionIn volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such that expelled lava violently froths into volcanic ash when pressure is suddenly lowered at the vent. Sometimes a lava plug will block the conduit to the summit, and when this occurs, eruptions are more violent.
Ring of FireThe Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur. The Ring of Fire is a horseshoe-shaped belt about long and up to about wide. The Ring of Fire includes the Pacific coasts of South America, North America, Russia's Kamchatka Peninsula, and some islands in the western Pacific Ocean.
GalerasGaleras (Urcunina among the 16th-century indigenous people) is an Andean stratovolcano in the Colombian department of Nariño, near the departmental capital Pasto. Its summit rises above sea level. It has erupted frequently since the Spanish conquest, with its first historical eruption being recorded on December 7, 1580. A 1993 eruption killed nine people, including six scientists who had descended into the volcano's crater to sample gases and take gravity measurements in an attempt to be able to predict future eruptions.
LandslideLandslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, shallow or deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides.
MontserratMontserrat (ˌmɒntsəˈræt ) is a British Overseas Territory in the Caribbean. It is part of the Leeward Islands, the northern portion of the Lesser Antilles chain of the West Indies. Montserrat is about long and wide, with roughly of coastline. It is nicknamed "The Emerald Isle of the Caribbean" both for its resemblance to coastal Ireland and for the Irish ancestry of many of its inhabitants. Montserrat is the only non-fully sovereign full member of the Caribbean Community and the Organisation of Eastern Caribbean States.
LastarriaLastarria is a high stratovolcano that lies on the border between Chile and Argentina. It is remote and the surroundings are uninhabited but can be reached through an unpaved road. The volcano is part of the Central Volcanic Zone, one of the four segments of the volcanic arc of the Andes. Over a thousand volcanoes - of which about 50 are active - lie in this over long chain of volcanoes, which is generatedby subduction of the Nazca Plate beneath the South American Plate.
