Pacaya
Overview
 
Pacaya is an active complex volcano
Complex volcano
A complex volcano, also called a compound volcano, is a volcano with more than one feature. They form because changes of their eruptive characteristics or the location of multiple vents in an area...

 in Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...

, which first erupted approximately 23,000 years ago and has erupted at least 23 times since the Spanish conquest of Guatemala. Pacaya rises to an elevation of 2552 metres (8,373 ft). After being dormant for a century, it erupted violently in 1965 and has been erupting continuously since then. Much of its activity is Strombolian
Strombolian eruption
Strombolian eruptions are relatively low-level volcanic eruptions, named after the Italian volcano Stromboli, where such eruptions consist of ejection of incandescent cinder, lapilli and lava bombs to altitudes of tens to hundreds of meters...

, but occasional Plinian
Plinian eruption
Plinian eruptions, also known as 'Vesuvian eruptions', are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in AD 79 ....

 eruptions also occur, sometimes showering the any of the nearby Departments with ash.

Pacaya is a popular tourist attraction.
Encyclopedia
Pacaya is an active complex volcano
Complex volcano
A complex volcano, also called a compound volcano, is a volcano with more than one feature. They form because changes of their eruptive characteristics or the location of multiple vents in an area...

 in Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...

, which first erupted approximately 23,000 years ago and has erupted at least 23 times since the Spanish conquest of Guatemala. Pacaya rises to an elevation of 2552 metres (8,373 ft). After being dormant for a century, it erupted violently in 1965 and has been erupting continuously since then. Much of its activity is Strombolian
Strombolian eruption
Strombolian eruptions are relatively low-level volcanic eruptions, named after the Italian volcano Stromboli, where such eruptions consist of ejection of incandescent cinder, lapilli and lava bombs to altitudes of tens to hundreds of meters...

, but occasional Plinian
Plinian eruption
Plinian eruptions, also known as 'Vesuvian eruptions', are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in AD 79 ....

 eruptions also occur, sometimes showering the any of the nearby Departments with ash.

Pacaya is a popular tourist attraction. Pacaya lies 30 kilometres (18.6 mi) southwest of Guatemala City
Guatemala City
Guatemala City , is the capital and largest city of the Republic of Guatemala and Central America...

 and close to Antigua
Antigua Guatemala
Antigua Guatemala is a city in the central highlands of Guatemala famous for its well-preserved Spanish Mudéjar-influenced Baroque architecture as well as a number of spectacular ruins of colonial churches...

. The volcano sits inside the Escuintla Department.

So far, the last activity reported has been the eruption that peaked on May 27, 2010, causing ash to rain down in Guatemala City, Antigua and Escuintla.

Geological history

The Pacaya volcano is a part of the Central American Volcanic Arc, a chain of volcanoes stretching from the northwest to the southeast along the Pacific coast of Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

, formed by the tectonic subduction
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...

 of the Cocos Tectonic Plate
Cocos Plate
The Cocos Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it.-Geology:...

 beneath the Caribbean Plate
Caribbean Plate
The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America....

. Pacaya lies on the southern edge of a sizable volcanic caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

 formed in the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 age which contains Lago de Amatitlán. This caldera has been the source of at least nine very large explosions over the past 300,000 years, erupting a total of about 70 cubic kilometres (16.8 cu mi) of magma
Magma
Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...

.

After the last caldera-forming eruption 23,000 years ago, several smaller vents within and around the caldera have seen eruptive activity. Pacaya is the largest post-caldera volcano, and has been one of Central America's most active volcanoes over the last 500 years. It has erupted at least 23 times since the Spanish conquest, producing basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

 and basaltic andesite
Andesite
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...

.

About 1,100 years ago, the volcano's edifice collapsed, causing a huge landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...

. Deposits from the landslide travelled about 25 kilometres (15.5 mi) from the volcano down to the Pacific coastal plain
Coastal plain
A coastal plain is an area of flat, low-lying land adjacent to a seacoast and separated from the interior by other features. One of the world's longest coastal plains is located in eastern South America. The southwestern coastal plain of North America is notable for its species diversity...

. The landslide left a large crater, within which the current active cone has grown. The presence of a magma chamber
Magma chamber
A magma chamber is a large underground pool of molten rock found beneath the surface of the Earth. The molten rock in such a chamber is under great pressure, and given enough time, that pressure can gradually fracture the rock around it creating outlets for the magma...

 at shallow depths beneath Pacaya means that distortion of the cone leading to instability and future landslides remains a hazard to the surrounding areas.

Recent eruptions

With its almost continuous activity, the volcano has been a popular location for tourism
Tourism
Tourism is travel for recreational, leisure or business purposes. The World Tourism Organization defines tourists as people "traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business and other purposes".Tourism has become a...

. Pacaya is easily accessible from Guatemala City
Guatemala City
Guatemala City , is the capital and largest city of the Republic of Guatemala and Central America...

 and from Antigua. The volcano and surrounding area now lie within the Pacaya National Park
National park
A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...

, which was created to supervise and protect tourism in this region. The Pacaya Park generates its income from tour groups who are charged a small fee to enter the park.

In 1998, several explosive eruptions emitted lava, debris and ash columns with a height of 1500 m
M
M is the thirteenth letter of the basic modern Latin alphabet.-History:The letter M is derived from the Phoenician Mem, via the Greek Mu . Semitic Mem probably originally pictured water...

 - 5000 m
M
M is the thirteenth letter of the basic modern Latin alphabet.-History:The letter M is derived from the Phoenician Mem, via the Greek Mu . Semitic Mem probably originally pictured water...

. Ash fall affected nearby cities including Guatemala city and La Aurora airport.

During 2006, a slight increase in Pacaya's volcanic activity brought about the creation of several lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 rivers that slowly flow down its slope. Word about these phenomena spread, and local tourism increased significantly.

May 2010 eruption

On May 27, 2010, the Pacaya volcano erupted, followed by several tremors. At approximately 20:00 hours there was a strong eruption ejecting debris and ash columns up to 1500 meters. Ash rained down in many Guatemalan cities to the northwest of the volcano, including Guatemala City. The volcanic ash fall pelted Guatemala City, and the international airport
International airport
An international airport is any airport that can accommodate flights from other countries and are typically equipped with customs and immigration facilities to handle these flights to and from other countries...

, La Aurora
La Aurora International Airport
La Aurora International Airport serves Guatemala City, Guatemala. It is located south of Guatemala City's center and from Antigua. It is administered by the Dirección General de Aeronáutica Civil....

. The National Coordinator for Disaster Reduction
Coordinadora Nacional para la Reducción de Desastres
The National Coordination for Disaster Reduction of Guatemala is an entity created to prevent disasters or reduce their impact on society, and coordinate disaster relief efforts....

 (CONRED) declared a red alert for the communities near the volcano, and recommended the evacuation of some of them. Noti7 reporter Anibal Archila, one of the first to cover the event, was reported killed by volcanic debris.

President Álvaro Colom
Álvaro Colom
Álvaro Colom Caballeros is the President of Guatemala for the 2008–2012 term and leader of the social-democratic National Unity of Hope .-Early years:...

 declared a state of calamity in the region adjacent to the volcano, and the Ministry of Education closed the schools in the departments of Guatemala, Escuintla and Sacatepequez. Heavy rainfall from Tropical Storm Agatha
Tropical Storm Agatha (2010)
Tropical Storm Agatha was a weak, but catastrophic tropical cyclone that brought widespread floods to much of Central America and was the deadliest tropical cyclone in the eastern Pacific since Hurricane Pauline in 1997. The first storm of the 2010 Pacific hurricane season, Agatha originated from...

worsened the emergency situation, causing lahars, landslides and widespread flooding across the country. However, people working in coffee fields considered the rain brought by the storm to be helpful, removing ash from their trees.

External links

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