Eruption column over Mount Pinatubo in the Philippines

An eruption column consists of hot volcanic ash emitted during an explosive volcanic eruption. The ash forms a column rising many kilometres into the air above the peak of the volcano. In the most explosive eruptions, the eruption column may rise over 40km, penetrating the stratosphere. Stratospheric injection of aerosolz by volcanoes is a major cause of short-term climate change. USGS.gov picture of Mt Pinatubo eruption File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... USGS.gov picture of Mt Pinatubo eruption File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... 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. ... 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 volcanoes in geology. ... The stratosphere is a layer of Earths atmosphere that is stratified in temperature, with warmer layers higher up and cooler layers farther down. ... http://visibleearth. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years Climate change refers to the variation in the Earths global climate or regional climates over time. ...

A common occurrence in explosive eruptions is for column collapse to occur. In this case, the eruption column is too dense to be lifted high into the air by the force of the explosion, and instead falls down the flanks of the volcano in the form of a pyroclastic flow. Pyroclastic flows sweep down the flanks of Mayon Volcano, Philippines, in 1984 Pyroclastic flows are a common and devastating result of some volcanic eruptions. ...

Formation of eruption columns

Eruption columns form in explosive volcanic activity, when the high concentration of volatile materials in the rising magma caused it to be disrupted into fine volcanic ash and coarser tephra. The ash and tephra are ejected at speeds of several hundred metres per second, and can rise rapidly to heights of several kilometres, lifted by enormous convection currents. Volatile is the name of more than one concept: A financial instrument with high volatility is considered volatile in economics. ... Magma is molten rock often located inside a magma chamber beneath the surface of the Earth. ... 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. ... Tephra, as a generic term, refers to air-fall material produced by a volcanic eruption - regardless of composition or fragment size. ... Convection is the transfer of heat by currents within a fluid. ...

Eruption columns may be transient, if formed by a discrete explosion, or sustained, if produced by a continuous eruption or closely spaced discrete explosions.

Column heights

Eruption column rising over Redoubt volcano, Alaska

Several factors control the height that an eruption column can reach. Intrinsic factors include the diameter of the erupting vent, the gas content of the magma, and the velocity at which it is ejected. Extrinsic factors can be important, with winds sometimes limiting the height of the column, and the local thermal temperature gradient also playing a role. The atmospheric temperature in the troposphere normally decreases by about 10 K/km, but small changes in this gradient can have a large effect on the final column height. Theoretically, the maximum achievable column height is thought to be about 55km. In practice, column heights ranging from about 2-45 km are seen. Image File history File links Download high resolution version (1024x689, 149 KB) Picture of Mount Redoubt Eruption Ascending eruption cloud from Redoubt Volcano as viewed to the west from the Kenai Peninsula. ... Image File history File links Download high resolution version (1024x689, 149 KB) Picture of Mount Redoubt Eruption Ascending eruption cloud from Redoubt Volcano as viewed to the west from the Kenai Peninsula. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... This article is about velocity in physics. ... I am cool. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ...

Eruption columns over 10-15 km high break through the tropopause and inject ash and aerosols into the stratosphere. Ash and aerosols in the troposphere are quickly removed by rain and other precipitation, but material injected into the stratosphere is much more slowly dispersed, in the absence of weather systems. Substantial amounts of stratospheric injection can have global effects: after Mount Pinatubo erupted in 1991, global temperatures dropped by about 0.5°C. The largest eruptions are thought to cause drops of up to several degrees, and are potentially the cause of some of the known mass extinctions. The tropopause is a boundary region in the atmosphere between the troposphere and the stratosphere. ... http://visibleearth. ... The stratosphere is a layer of Earths atmosphere that is stratified in temperature, with warmer layers higher up and cooler layers farther down. ... Rain falling For other uses see Rain (disambiguation). ... Composite satellite image showing the progress of a hurricane weather system approaching the East Coast of the United States Weather comprises all the various phenomena that occur in the atmosphere of a planet. ... 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 (MCMXCI) is a common year starting on Tuesday of the Gregorian calendar. ... An extinction event (also extinction-level event, ELE) is a period in time when a large number of species die out. ...

Hazards

Column collapse

Eruption columns may be so laden with dense material that they are too heavy to be supported by convection currents. When this happens, the column or more commonly part of the column may collapse under gravity, generating a pyroclastic flow which can travel down the flanks of a volcano at speeds of over 100 km/hour. Column collapse is one of the most common and dangerous volcanic hazards. It has been suggested that gravitation be merged into this article or section. ... Pyroclastic flows sweep down the flanks of Mayon Volcano, Philippines, in 1984 Pyroclastic flows are a common and devastating result of some volcanic eruptions. ... Eruption redirects here. ...

Aircraft

Several eruptions have seriously endangered aircraft which have encountered the eruption column. In 1982, two aircraft flew into the upper reaches of an eruption column generated by Galunggung volcano, and the ash severely damaged both the exterior of the planes and their engines. Both craft were forced to descend rapidly due to loss of engine power and make emergency landings in Jakarta. 1982 (MCMLXXXII) is a common year starting on Friday of the Gregorian calendar. ... Galunggung (Galoen-gong, Gunung Galunggung) is a stratovolcano on Java, Indonesia. ... Motto: Jaya Raya (Indonesian): Prosper and Great Founded 22 June 1527 Governor Sutiyoso Area 661. ...

Similar damage to aircraft occurred due to an eruption column over Redoubt volcano in Alaska in 1989. Following the eruption of Mount Pinatubo in 1991, aircraft were diverted to avoid the eruption column, but nonetheless, ash dispersing over a wide area caused damage to 16 aircraft, some as far as 1000 km from the volcano. Mount Redoubt is an active volcano in the Aleutian Range on the Alaska Peninsula in Alaska, at 60°29 North 152°45 West. ... Official language(s) English Capital Juneau Largest city Anchorage Area  - Total  - Width  - Length  - % water  - Latitude  - Longitude Ranked 1st 663,267 mi² / 1,717,854 km² 808 mi / 1,300 km 1,479 mi / 2,380 km 13. ... -1... 1991 (MCMXCI) is a common year starting on Tuesday of the Gregorian calendar. ...

References

1. Casadevall T.J.,Delos Reyes P.J., Schneider D.J. (1993), The 1991 Pinatubo Eruptions and Their Effects on Aircraft Operations, in Fire and Mud: Eruptions and Lahars of Mount Pinatubo, Philippines, published by USGS and PHIVOLCS
2. Glaze L.S., Baloga S.M. (1996), Sensitivity of buoyant plume heights to ambient atmospheric conditions: Implications for volcanic eruption columns, Journal of Geophysical Research, v. 101, p. 1529-1540
3. Wilson L., Sparks R.S.J., Huang T.C., Watkins N.D. (1978), The control of volcanic column heights by eruption energetics and dynamics, Journal of Geophysical Research, v. 83, p. 1829-1836

External links

• USGS information
• Description of Galunggung eruption column