6 Jun 11 -
The volcanic complex Cordón Caulle erupted on Saturday in
southern Chile, causing the evacuation of thousands of people in
surrounding areas.
A column of steam and ash reached more than ten miles high and then
headed for Argentina as an eerie lightning show danced through the ash
clouds overnight. (Note: MetSul.com says 10 miles. All of my other
sources say 10 kilometers, which is only 6 miles. I don't know which
number is correct.)
Authorities initially said the Puyehue volcano was involved, but later
said the eruption was taking place about 2
˝
miles (4 km) from that peak.
A rift more than 6 miles (10 km) long and 3 miles (5 km) across was torn
in the earth's crust, officials said Saturday night.
The Cordón Caulle complex lies about 550 miles (900 km) south of the
capital, Santiago. Standing some 7,280 feet (2,240 meters) tall, Puyehue
volcano last erupted in 1960, the same year that a major earthquake
struck the country.
Authorities put the area around the volcano on alert after a flurry of
earthquakes. The National Emergency Office says it has recorded an
average of 230 tremors an hour.
Amazingly, there were no immediate reports of injuries.
So far, Bariloche, a major tourist destination in Argentina, is the city
most affected by the cloud of ash and rocks. Around four in the
afternoon in Bariloche the sky was black - "pitch black," said one
resident - and ash began falling. The famous Lake Nahuel Huapi was
covered with ash.
At first, shocked residents thought it was snowing, but once they felt
the ash, they realized that it was something else. "It
feels like dirt is falling," says the narrator on this video.
Officials urged people to stock up on food, cover their mouths and noses
against the ash, and stay inside.
By early Saturday night, the ash measured between 1.8 and 2 inches (3-5
cm) deep in most of Bariloche. The eruption triggered "panic buying,"
with many residents rushing to supermarkets and petrol stations to stock
food, water and gasoline.
With a remarkable accumulation of ash and zero visibility, Briloche
Airport was closed to air traffic. Now it's nighttime, says this article
on MetSul, and thunderstorms are common in the volcanic clouds, a sign
that the explosion is strong. By morning, there are fears that a large
amount of ash will have accumulated.
Another concern is that it may rain on Tuesday, in which case the weight
of the ash added to the volumes of water could compromise structures,
possibly leading to collapsing rooftops.
One cannot rule out that the ash can reach even the region of Buenos
Aires or southern Brazil in the coming days, this article continues.
There are historical precedents of ash from eruptions in Chile reaching
the center of Argentina and Rio Grande do Sul, but in most cases, the
eruptions occurred in the center and not in South Chile.
The transport of ash to distant places such as southern Brazil will
depend on prevailing winds at altitude jet streams and how long and
intensive the eruption continues. Models indicate that during the week,
wind currents could send the ash over the North and Northeast.
Chile's chain of about 3,000 volcanoes is the world's second largest
after Indonesia. Some 50 to 60 eruptions have been recorded over the
past 450 years, and 500 are potentially active.
Chaiten volcano, for example, erupted spectacularly in 2008 for the
first time in thousands of years, spewing molten rock and a vast cloud
of ash that reached the stratosphere, coated towns in Argentina, and was
visible from space.
If this eruption continues with such intensity for a long time, which is
virtually unpredictable, it could force temperatures lower this winter,
says this article on MetSul.
Volcanoes in the tropics tend to influence the climate on a global
scale, especially the more powerful eruptions, which may affect the
hemispheric and regional climate.
