posted on Jun, 11 2004 @ 10:03 PM
Mt. Bromo erupted on the Tuesday previous to Thursday's Mt Awu eruption.
Originally posted by cmdrkeenkid
anyone have any idea how this may affect the atmosphere?
Volcanic eruptions disperse quantities of dust and gas into the atmosphere that become aerosols; small particulates that can hang around in the
atmosphere for long periods of time. The major gas content is usually sulphur dioxide which can react with moisture, oxygen and sunlight to form a
sulphuric acid haze.
Numerous factors such as eruption force and duration, altitude of the volcano's summit and the volcano's latitude can have differing impacts on the
atmosphere with how those aerosols are dispersed.
In a simplistic "rule of thumb" explanation: If the aerosols of a large eruption reach the stratosphere, they can reflect some of the sun's
emissions back into space or block (absorb) the emissions causing a cooling effect. If the eruption is small, the aerosols only reach into the
troposphere where they can cause brief regional warming effects by blocking returning solar emissions from the earth. Sometimes, short-lived regional
cooling effects are observed. These events are short lived since their lower altitude aerosols settle out of the atmosphere after a few months.
Large eruptions such as Mt. Pinatubo (1991) and El Chi chon (1982) brought on cooling effects. Mt. Pinatubo was responsible for a cooling effect that
started shortly after it's eruption beginning in 1991 and lasting through most of 1994. Usually, it takes a few months for the aerosols to propagate
throughout the stratosphere before a cooling effect is noticed.
Smaller eruptions like Mt. St. Helens resulted in some short term regional cooling effects.
April, 1815, saw a large eruption of the Tambora Volcano in Indonesia, perhaps the most powerful eruption on record. Tambora's cloud of dust and gas
lowered global temperatures by as much as 3°C. Most of the northern hemisphere experienced sharply cooler temperatures during the summer months even a
year after the eruption. 1816 was known as "the year without a summer" in parts of Europe and in North America.
Fortunately, neither the Mt. Bromo or Mt Awu eruptions were near this magnitude. They were more on the order of Mt. St. Helens. Therefore, short term
regional cooling is expected. However, it isn't currently clear if the volcanic activity is settled yet.
[edit on 11-6-2004 by Outland]