Volcán Santamaria is a large active volcano in the Western Highlands of Guatemala, close to the city of Quetzaltenango. Its eruption in 1902 was the second-largest eruption of the 20th century, and the third large eruption of that one year, after Mt._Pelée in Martinique and Soufriere in Guadeloupe. Santiaguito volcano, seen from the summit of Santamaria. ... Elevation has several related meanings: Geography The elevation of a geographic location is its height above mean sea level (or possibly some other fixed point). ... This article is about longitude and latitude; see also UTM coordinate system Map of Earth showing lines of latitude (vertically) and longitude (horizontally); large version (pdf) The geographic (earth-mapping) coordinate system expresses every horizontal position on Earth by two of the three coordinates of a spherical coordinate system which... The most general definition of mountain range is a group of mountains bordered by lowlands. ... Mountains can be characterized in several ways. ... View of Mount Rainier, a stratovolcano. ... Quetzaltenango is the second most populous city of Guatemala, after Guatemala City, and is the capital of Quetzaltenango Department. ... 1902 was a common year starting on Wednesday (see link for calendar). ... Mount Pelée (French: Montagne Pelée, Bald Mountain) is an active volcano on the northern tip of the French département of Martinique in the Caribbean. ...

The 1902 eruption blasted away most of one side of the 3,772m tall mountain. Some 5.5 cubic km (1.3 cubic miles) of volcanic material was ejected during the 19-day eruption, and the ash column reached heights of up to 28km. The eruption devastated the surrounding areas.

In 1922, a new volcanic vent formed in the enormous crater, and formed a new volcano, named Santiaguito. Santiaguito has been erupting ever since and now forms a cone a few hundred metres tall, reaching an elevation of about 2,500m. Today, it is possible to climb to the top of Santamaria and look down on the ongoing eruptions at Santiaguito, 1,200m below, a situation which may be unique in the world. 1922 was a common year starting on Sunday (see link for calendar). ...

Geological history

Santamaria is part of the Sierra Madre range of volcanoes, which extends along the western edge of Guatemala, separated from the Pacific Ocean by a broad plain. The volcanoes are formed by the subduction of the Cocos Plate under the Caribbean Plate. This is a list of mountain ranges organized alphabetically by continent. ... Subduction zones mark sites of convective downwelling of the Earths lithosphere. ... The Cocos Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America. ... Detail of the Cocos and Caribbean plates from: [Image:Plate tectonics map. ...

Eruptions at Santamaria are estimated to have begun about 30,000 years ago. For several thousand years, eruptions seem to have been small and frequent, building up the large cone of the volcano, reaching about 1,400 m above the plain on which the nearby city of Quetzaltenango sits. Following the cone-building eruptions, activity seems to have changed to a pattern of long periods of repose followed by the emission of small lava flows from vents on the flanks. Quetzaltenango is the second most populous city of Guatemala, after Guatemala City, and is the capital of Quetzaltenango Department. ... In computer programming jargon, lava flow is a problem in which computer code, usually written under less than optimal conditions, is put into production and then built on when still in a developmental state. ...

The cone built by the eruptions had a volume of about 10 km³, and consisted of a mixture of basalt and andesite lavas. Basalt Basalt is an extrusive igneous rock, sometimes porphyritic, and is often both fine-grained and dense. ... Andesite is an igneous, volcanic (extrusive) rock, of intermediate composition, with aphanitic to porphyritic texture. ...

1902 eruption

Steam rises from Santiaguito. The area of the flank destroyed by the 1902 eruption can be clearly seen. Lahar deposits snake down river valleys to the left of the image

The first eruption of Santamaria in recorded history occurred in October 1902. Before 1902 the volcano had been dormant for at least 500 years and possibly several thousand years, but its awakening was clearly indicated by a seismic swarm in the region starting in January 1902. The eruption began on 24 October, and the largest explosions occurred over the following two days, ejecting an estimated 5.5 km³ of magma. The eruption was one of the largest of the 20th century, comparable in magnitude to that of Mount Pinatubo in 1991. October is the tenth month of the year in the Gregorian Calendar and one of seven Gregorian months with the length of 31 days. ... 1902 was a common year starting on Wednesday (see link for calendar). ... January is the first month of the year in the Gregorian Calendar and one of seven Gregorian months with the length of 31 days. ... 1902 was a common year starting on Wednesday (see link for calendar). ... October 24 is the 297th day of the year (298th in leap years) in the Gregorian Calendar, with 68 days remaining. ... This article is about the type of molten rock. ... Mount Pinatubo is an active volcano located on the island of Luzon in the Philippines, at the intersection of the borders of the provinces of Zambales, Bataan, and Pampanga. ... 1991 is a common year starting on Tuesday of the Gregorian calendar. ...

The pumice formed in the climactic eruption fell over an area of about 273,000 km², and volcanic ash was detected as far away as San Francisco, 4,000 km away. The eruption tore away much of the south-western flank of the volcano, leaving a crater about 1 km in diameter and about 300 m deep, stretching from just below the summit to an elevation of about 2,300 m. Top stone is obsidian, below that is pumice and in lower right hand color is rhyolite (light color). ... Diamond Head, a well-known backdrop to Waikiki in Hawaii, is an ash cone that solidified into tuff Volcanic ash is the term for very fine rock and mineral particles less than 2 mm in diameter that are ejected from a volcanic vent. ... This article is about the city in California. ...

Because of the lack of previous activity at Santamaria, local people did not recognise the preceding seismicity as warning signs of an eruption. At least 5,000 people died as a result of the eruption itself, and a subsequent outbreak of malaria killed many more.
Red blood cell infected with Malaria (Italian: bad air; formerly called ague or marsh fever in English) is an infectious disease which in humans causes about 350-500 million infections and over 1 million deaths annually, mainly in the tropics and sub-Saharan Africa. ...

Santiaguito

The 1902 eruption was followed by 20 years of quiet. In 1922, new eruptions began, with the extrusion of a lava dome in the crater left by the 1902 eruption. The dome was christened Santiaguito, and since then, activity has been virtually constant. Santiaguito now reaches a height of about 2,500 m, and has a volume of about 1 km³. From the summit of Santamaria, it is possible to look down on the eruptions at Santiaguito a mile below. 1922 was a common year starting on Sunday (see link for calendar). ... In volcanology, a lava dome is mound-shaped growth resulting from the eruption of high-silica lava (such as rhyolite) from a volcano. ...

Dome growth at Santiaguito has alternated between growth caused by the emission of lava flows, and inflation caused by the injection of magma into the middle of the dome. These dome growth types are described by volcanologists as exogenous and endogenous respectively. Activity has been concentrated at several different vents, and Santiaguito now has the appearance of several overlapping domes.

Although most of Santiaguito's eruptive activity has been relatively gentle , occasional larger explosions have occurred. In 1929, part of the dome collapsed, generating pyroclastic flows which killed several hundred people. Occasional rockfalls have generated smaller pyroclastic flows, and vertical eruptions of ash to heights of a few kilometres above the dome are common. 1929 was a common year starting on Tuesday (link will take you to calendar). ... Pyroclastic flows are a common and devastating result of some volcanic eruptions. ...

Volcanic hazards at Santamaria

A hot lahar rushes down a river valley near El Palmar in 1989

The areas to the south of Santamaria are considerably affected by volcanic activity at Santiaguito. Currently, the most common volcanic hazard at Santamaria is lahars, which frequently occur in the rainy season due to heavy rainfall on loose volcanic deposits. The town of El Palmar, 10 km from Santiaguito, has been destroyed twice by lahars from Santiaguito, and infrastructure such as roads and bridges have been repeatedly damaged. Lahar deposits from Santiaguito have affected rivers all the way downstream to the Pacific Ocean. A lahar is a mixture of rock, mud, and water that flows down from a volcano (or occasionally other mountains), typically along a river valley. ... The wet season is a term commonly used when describing the weather in the tropics. ... This article is about the edifice. ...

Lava flows do not occur frequently from Santiaguito, and tend not to stretch more than a few kilometres from the dome. The magma at Santiaguito is rich in silica and is thus highly viscous. Flows are therefore very slow-moving and are of little danger to human life, although propery damage may occur. Fast-moving pyroclastic flows can occur, and these may travel several kilometres from the dome. The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... The Pitch Drop Experiment at the University of Queensland. ...

One hazard which could be devastating is the collapse of Santamaria itself. The 1902 crater has left the southern flank of the mountain above Santiaguito highly over-steepened, and a large earthquake or eruption from Santiaguito could trigger a huge landslide, which might cover up to 100 km². However, this is thought to be unlikely in the short term. Global earthquake epicenters, 1963–1998 An earthquake is a trembling or a shaking movement of the Earths surface. ... This entry refers to the geological term landslide. ...

In light of the threat it poses to nearby populations, Santamaria has been designated a Decade Volcano, identifying it as a target for particular study by volcanologists to mitigate any future natural disasters at the volcano. A map showing locations of the 16 Decade Volcanoes The Decade Volcanoes are 16 volcanoes identified by the International Association of Volcanology and Chemistry of the Earths Interior (IAVCEI) as being worthy of particular study in light of their history of large, destructive eruptions and proximity to populated areas. ... A natural disaster is the consequence or effect of a hazardous event, occurring when human activities and natural phenomenon (a physical event, such as a volcanic eruption, earthquake, landslide etc. ...

External links

1. Santamaria - pictures and recent activity, from VolcanoWorld (http://volcano.und.nodak.edu/vwdocs/volc_images/south_america/guat/santa_maria.html)
2. Santamaria Decade Volcano information (http://www.geo.mtu.edu/volcanoes/santamaria/decade.html)