Galeras
Galeras, December 2005
Elevation	4,276 metres (14,029 feet)
Location	Colombia
Range	Andes
Coordinates	1°13′0″N, 77°22′0″W
Type	Complex volcano
Volcanic arc/belt	Andean Volcanic Belt
Last eruption	2008

Galeras (Urcunina among the XVI century indigenous people) is an active stratovolcano in Colombia, near the city of Pasto. In topography a summit is a point on a surface which is higher in Elevation than all points immediately adjacent to Colombia (kəˈlʌmbɪə officially the Republic of Colombia () is a country in northwestern South America. A mountain range is a chain of Mountains bordered by highlands or separated from other mountains by passes or valleys The Andes form the world's longest exposed Mountain range. They lie as a continuous chain of highland along the western coast of South America. A geographic coordinate system enables every location on the Earth to be specified in three coordinates using mainly a spherical coordinate system. Mountains can be characterized in several ways Some mountains are Volcanoes and can be characterized by the type of lava and eruptive history A complex volcano, also called a compound volcano is a Volcano with more than one feature. A volcanic arc is a chain of volcanic islands or Mountains formed by Plate tectonics as an oceanic Tectonic plate subducts under A volcanic belt is a large volcanically active region Other terms are used for smaller areas of activity such as volcanic fields Volcanic belts are found above zones The Andean Volcanic Belt is a major Volcanic belt in coastal Colombia, Bolivia, Peru, Ecuador and Argentina, South Plate tectonics and hotspots Divergent plate boundaries At the A stratovolcano, also called a composite volcano is a tall conical Volcano composed of many layers of hardened Lava, Tephra, and Volcanic Colombia (kəˈlʌmbɪə officially the Republic of Colombia () is a country in northwestern South America. Pasto, officially San Juan de Pasto, is the capital of the department of Nariño, located in southwest Colombia Its summit lies 4,276 m (14,029 feet) above sea level. Mean sea level (MSL is the average (mean height of the Sea, with reference to a suitable reference surface It has erupted frequently since the Spanish conquest, its first historical eruption data from December 7, 1580^[1], and in 1993, an eruption killed nine people, including six scientists who had descended right into the volcano's crater to sample gases. Events 43 BC - Marcus Tullius Cicero assassinated 1696 - Connecticut Route 108, one of the oldest highways Year 1993 ( MCMXCIII) was a Common year starting on Friday (link will display full 1993 Gregorian calendar) ^[2]

Geological history

Galeras has been an active volcano for at least a million years. Two major caldera-forming eruptions have occurred, the first about 560,000 years ago in an eruption which expelled about 15 cubic kilometres of material, and the second some time between 40,000 and 150,000 years ago, in a smaller but still sizable eruption of 2km³ of material. A caldera is a cauldron-like volcanic feature formed by the collapse of land following a volcanic eruption Subsequently, part of the caldera wall has collapsed, probably due to instabilities caused by hydrothermal activity, and later eruptions have built up a smaller cone inside the now horseshoe-shaped caldera. A horseshoe is a U-shaped item made of metal or of modern synthetic materials nailed or glued to the Hooves of Horses and some other Draught

At least six large eruptions have occurred in the last 5,000 years, most recently in 1886, and there have been at least 20 small to medium sized eruptions since the 1500s. Year 1886 ( MDCCCLXXXVI) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common In light of its violent eruption history and proximity to the 450,000 people of Pasto, Galeras was designated a Decade Volcano in 1991, identifying it as a target for detailed study as part of the United Nations' International Decade for Natural Disaster Reduction. The Decade Volcanoes are 16 Volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI as being worthy Year 1991 ( MCMXCI) was a Common year starting on Tuesday (link will display full calendar of the Gregorian Calendar. The United Nations ( UN) is an International organization whose stated aims are to facilitate cooperation in International law, International security

1993 eruption

Galeras had become active in 1988 after 10 years of dormancy. In January 14TH 1993, the volcano erupted when several volcanologists were inside the crater taking measurements. Year 1993 ( MCMXCIII) was a Common year starting on Friday (link will display full 1993 Gregorian calendar) Volcanology (also spelled vulcanology) is the study of Volcanoes, Lava, Magma, and related geological and Geophysical phenomena The scientists had been visiting Pasto for a conference related to the volcano's designation as a Decade Volcano. Six were killed, together with three tourists on the rim of the crater.

Controversy has surrounded the events of the disaster, with competing viewpoints represented in various books. Claims have been made that the leader of the expedition, Stanley Williams, ignored basic safety procedures, as well as seismic evidence that an eruption was imminent, thus placing himself and others in danger unnecessarily.

A prediction had been made three days before the eruption based on B-Type activity seen on a seismograph. Seismic B-types had been used successfully to predict eruptions on other volcanoes. However, Williams chose to do the risk assessment based on his own technique using gas emissions, which had indicated that there was little likelihood of an eruption at Galeras. This page is about the physical properties of gas as a state of matter

Twenty-first century activity

the Galeras Volcano', Aerial image by NASA showing activity. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program City of Pasto on the right. Pasto, officially San Juan de Pasto, is the capital of the department of Nariño, located in southwest Colombia

Activity at a low level has continued at Galeras, with small explosions occasionally dusting nearby villages and towns with ash. Volcanic ash consists of small Tephra, which are bits of pulverized rock and glass created by volcanic eruptions less than in diameter The volcano has continued to be well studied, and predictions of eruptions at the volcano have improved. One phenomenon which seems to be a reliable precursor to eruptive activity is a low-frequency seismic event known as a 'tornillo'. Seismology (from Greek grc σεισμός seismos, "earthquake" and grc -λογία -logia) is the scientific study of Earthquakes These have occurred before about four-fifths of the explosions at Galeras, and the number of tornillo events recorded before an eruption is also correlated with the size of the ensuing eruption. In Probability theory and Statistics, correlation, (often measured as a correlation coefficient) indicates the strength and direction of a linear

More than 100 minor tremors were felt during a major eruption in April 2002, although no damage or injury was reported. April 2002: January - February - March - April - May - June - July - August - September An eruption in November 2005^[3] forced an evacuation of the dangerous area surrounding the volcano and about 9400 people from nearby villages (mostly farmers) were ordered to leave. The city of Pasto, about 9 km from the volcano, was blanketed by a layer of ash after the volcanic explosion, forcing the residents to don goggles and face masks. Pasto, officially San Juan de Pasto, is the capital of the department of Nariño, located in southwest Colombia

Numerous minor tremors and ash emissions since March 2006, culminated on Wednesday, July 12, 2006 in three explosive eruptions, producing an ash and gas column reaching an altitude of 8 kilometers. Stories without links will be removed. News stories must be in English Events 1191 - Saladin 's garrison surrenders ending the two-year Siege of Acre. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Rock falls and pyroclastic flows were reported from towns as distant as Consacá, 11. A pyroclastic flow (also known as a pyroclastic density current) is a common and devastating result of some volcanic eruptions. 4 kilometers west of the main crater. The Colombian government has repeatedly ordered evacuations to temporary shelters, of more than 8500 people residing in the highest risk areas surrounding the volcano,^[4][5] with hopes of eventual assistance toward permanent relocation. ^[6]

Space radar image of Galeras Volcano

On Thursday, January 17, 2008 the volcano erupted around 8 p. Events 38 BC - Octavian marries Livia Drusilla. 1287 - King Alfonso III of Aragon invades Minorca 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common m. There were no immediate reports of injuries or serious property damage. Later the experts confirmed partial damage in the national and local TV towers. Radio masts and towers are typically tall structures designed [1]^[7]

References

• Marta Lucia Calvache V. , Gloria Patricia Cortés, Stanley N. Williams (1997), Stratigraphy and chronology of the Galeras volcanic complex, Colombia, Journal of Volcanology and Geothermal Research, v. 77, p. 5
• Peter J. Baxter, Austin Gresham (1997), Deaths and injuries in the eruption of Galeras Volcano, Colombia, 14 January 1993, Journal of Volcanology and Geothermal Research, v. 77, p. 325-338
• Lourdes Narváez M. , Roberto A. Torres C. , Diego M. Gómez M. , Gloria Patricia Cortés J. , Héctor Cepeda V. , John Stix (1997), 'Tornillo'-type seismic signals at Galeras volcano, Colombia, 1992-1993, Journal of Volcanology and Geothermal Research, v. 77, p. 159

Notes

External links

• Galeras volcano website
• Global Volcanism Program
• VolcanoWorld information
• BBC on the November 2005 eruption.
• Colombia: Galeras volcano situation map