A erupção do Pinatubo, que afetou significativamente o clima da Terra, começou há 32 anos

The eruption column of Mount Pinatubo on June 12, 1991, three days before the climactic eruption

      

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Cabusilan Mountains separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The volcano's Plinian/Ultra-Plinian eruption on June 15, 1991, produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya bringing a lethal mix of ash and rain. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and altering the river systems months to years after the eruption.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes  or 10 km³ of magma, and 20,000,000 tonnes of SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of particulate into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C and ozone depletion temporarily increased substantially.
    

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A erupção do Pinatubo, que afetou significativamente o clima da Terra, começou há 31 anos

The eruption column of Mount Pinatubo on June 12, 1991, three days before the climactic eruption

    

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Cabusilan Mountains separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The volcano's Plinian/Ultra-Plinian eruption on June 15, 1991, produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya bringing a lethal mix of ash and rain. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and altering the river systems months to years after the eruption.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes  or 10 km³ of magma, and 20,000,000 tonnes of SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of particulate into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C and ozone depletion temporarily increased substantially.
    

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Uma erupção do Pinatubo afetou significativamente o clima em toda a Terra há trinta anos

The eruption column of Mount Pinatubo on June 12, 1991, three days before the climactic eruption

    

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Cabusilan Mountains separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The volcano's Plinian/Ultra-Plinian eruption on June 15, 1991, produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya bringing a lethal mix of ash and rain. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and altering the river systems months to years after the eruption.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes  or 10 km³ of magma, and 20,000,000 tonnes of SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of particulate into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C and ozone depletion temporarily increased substantially.
    

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Começou há 29 anos uma erupção que afetou significativamente o clima em toda a Terra

The eruption column of Mount Pinatubo on June 12, 1991, three days before the climactic eruption

    

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Cabusilan Mountains separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The volcano's Plinian/Ultra-Plinian eruption on June 15, 1991, produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya bringing a lethal mix of ash and rain. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and altering the river systems months to years after the eruption.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes  or 10 km³ of magma, and 20,000,000 tonnes of SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of particulate into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C and ozone depletion temporarily increased substantially.
    

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O Pinatubo, vulcão das Flipinas, teve há 28 anos uma erupção que afetou o clima terrestre

The eruption column of Mount Pinatubo on June 12, 1991, three days before the climactic eruption

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Cabusilan Mountains separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The volcano's Plinian/Ultra-Plinian eruption on June 15, 1991, produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya bringing a lethal mix of ash and rain. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and altering the river systems months to years after the eruption.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes (1.1×10¹⁰short tons) or 10 km³ of magma, and 20,000,000 tonnes (22,000,000 short tons) of SO
2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of particulate into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C and ozone depletion temporarily increased substantially.
  

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O Pinatubo, vulcão das Flipinas, teve há 23 anos uma erupção que afetou o clima do mundo inteiro

The eruption column of Mount Pinatubo on June 12, 1991, three days before the climactic eruption

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Cabusilan Mountains separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The volcano's Plinian/Ultra-Plinian eruption on June 15, 1991, produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya bringing a lethal mix of ash and rain. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and altering the river systems months to years after the eruption.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes (1.1×10¹⁰short tons) or 10 km³ of magma, and 20,000,000 tonnes (22,000,000 short tons) of SO
2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of particulate into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C and ozone depletion temporarily increased substantially.

in Wikipédia

Aviação e vulcanismo no Público

80 casos documentados nos últimos 20 anos
Cinzas vulcânicas: um novo perigo para a aviação?

As poeiras dos vulcões podem fazer parar os motores dos aviões

As cinzas cuspidas pelos vulcões são um grande risco para a aviação civil, porque podem danificar os motores dos aviões e reduzir drasticamente a visibilidade. Por isso é que foram encerrados inúmeros aeroportos por causa da erupção do vulcão islandês.

Ao longo dos últimos 20 anos, foram registados 80 casos de aviões apanhados em nuvens de partículas vulcânicas. As cinzas provocaram a perda de dois Boeing 747 e danificaram outros 20 aparelhos, com custos de reparação na ordem de centenas de milhões de euros, segundo peritos.

“Na alta atmosfera, onde circulam os aviões comerciais, a cinza vulcânica pode causar uma avaria no motor, danificar as pás das turbinas ou ainda as sondas electrónicas de Pitot, podem provocar a perda de aparelhos e mortes”, segundo o jornal especializado "Natural Hazards".

Com o tráfego de passageiros a aumentar 5 por cento ao ano no mundo, “o carácter imprevisível das erupções vulcânicas pode fazer deste novo risco uma ameaça significativa”, dizem peritos da Noruega e da Austrália nesta revista de 2009.

“A ameaça para a aviação é óbvia”, disse hoje à AFP Kjetil Toerseth, responsável pelas questões de poluição no instituto norueguês de investigação aérea.

“A poeira pode fazer parar os motores, mas pode apenas fazer alguns danos, e é necessário então fazer uma verificação completa dos motores se sabemos que o avião atravessou uma nuvem de cinza", acrescentou.

Para informar a aviação internacional sobre a posição e os movimentos destas nuvens, foram instalados “centros de conselho sobre as cinzas vulcânicas” em institutos meteorológicos em nove regiões do mundo.

O primeiro caso amplamente documentado de um avião que atravessou uma nuvem de cinzas vulcânicas foi o de um voo da British Airways em 1982, no momento da erupção do vulcão indonésio Gulanggung.

Todos os reactores do avião perderam a potência enquanto o aparelho atravessava uma nuvem de cinzas. A aeronave caiu mais de 4 mil metros antes de chegar a um lençol de ar não poluído, o que permitiu o recomeço dos motores.

O avião conseguiu então finalmente uma aterragem de urgência em Jacarta, apesar de um dos pára-brisas ter ficado completamente opaco por causa das cinzas.

Cinzas podem manter-se vários meses

Em 1989, um avião assegurando o voo KLM 747 entre Amesterdão e Anchorage, no Alasca, deu por si no meio de uma nuvem de cinzas do vulcão Redoubt, a 177 quilómetros da cidade norte-americana, apesar dos sistemas de alerta previstos, o que levou à perda de potência dos motores. Conseguiu ainda aterrar em Anchorage, mas a substituição dos quatro motores danificados custou 80 milhões de dólares.

Durante as grandes erupções do vulcão indonésio de Pinatubo em 1991 – quando as nuvens de cinzas tiveram ainda uma influência sobre o clima – foram reportados mais de 40 incidentes com aviões.

“A influência sobre o clima depende de onde decorrem as erupções vulcânicas”, disse hoje à AFP Yves Tourre, investigador da dinâmica do clima no Instituto Meteorológico francês.

Nos trópicos – no caso de Pinatubo – as nuvens de cinzas podem-se manter “vários meses, até mesmo um ano” a mais de 18 quilómetros de altitude, bloqueando os raios solares, com um impacto na temperatura ao sol, diz Tourre. Mas a situação deverá ser diferente no caso do vulcão islandês.

in Público - ler notícia

NOTA: a notícia tem um lapso - coloca o Pinatubo na Indonésia (é lá perto - as Filipinas são logo a seguir...) mas não deixa de ser interessante.