2011 Puyehue-Cordón Caulle eruption
Coordinates: 40°35′25″S 72°07′02″W / 40.59028°S 72.11722°W The 2011 Puyehue-Cordón Caulle eruption () is a volcanic eruption that began in the Puyehue-Cordón Caulle volcanic complex in Chile on June 4, 2011. At least 3,500 people were evacuated from nearby areas, while the ash cloud reached within days cities all around the Southern hemisphere, including Bariloche, Buenos Aires, Montevideo, Stanley, Porto Alegre, Cape Town, Hobart, Perth, Adelaide, Melbourne and Auckland, forcing airlines to cancel hundreds of international and domestic flights and causing travel chaos.
By 18 June the ash cloud had circled the Earth: the said that "the tip of the cloud that has travelled around the world has more or less reached the town of Coyhaique", about 600 kilometres south of the Puyehue-Cordón Caulle.
Although the eruption is referred to as coming from Puyehue volcano, it actually came from a vent in the adjacent Cordón Caulle volcano located some few km northwest of the Puyehue stratocone. Cordón Caulle is a volcanic fissure and has erupted many times in recorded history, most recently in 1960, whereas Puyehue has remained dormant. Cordón Caulle's last eruption occurred in 1960 following the 1960 Valdivia earthquake days earlier.
Eruption
The Southern Andean Volcano Observatory (OVDAS) of Servicio Nacional de Geología y Minería de Chile (SERNAGEOMIN) reported on April 27, 2011, 15:30 local time, an increased seismicity at the Puyehue-Cordón Caulle and set the alert Level to 3, Yellow.
Between 20:00 on June 2 and 19:59 on June 3, OVDAS reported that about 1,450 earthquakes at Puyehue-Cordón Caulle were detected, or an average of about 60 earthquakes per hour. Scientists and regional authorities flew over the volcano, noting no significant changes. The alert level remained at 3, yellow. Area residents reported feeling earthquakes during the evening of June 3 through the morning of June 4.
On June 4, 11:30 local time, a new round of eruption in the Puyehue volcano began. For a six-hour period on 4 June seismic activity increased to an average of 230 earthquakes per hour, at depths of 1–4 km. About 12 events were magnitudes greater than 4 of Richter magnitude, and 50 events were magnitudes greater than 3. The alert level was raised to 5, red.
At 15:15 local time OVDAS reported an explosion and a 5 kilometres (3.1 mi)-wide ash-and-gas plume that rose to an altitude of 10 kilometres (33,000 ft) above sea level. The plume drifted south at 5 kilometres (16,000 ft) altitude, and southeast and east at 10 kilometres (33,000 ft) altitude. The alert level was raised to 6, red.
After 18 days it first erupted, Lava begun spilling from volcano, heading west and flowing "slowly by a channel about 50 meters wide and 100 feet long."
Evacuation
A "red alert" was declared pre-emptively by the National Emergencies' Office (ONEMI) for regions near the volcano: Puyehue, Río Bueno, Futrono, and Lago Ranco; initially 600 persons were evacuated. The "red alert" was later extended for the Los Ríos Region area: the areas of Pocura, Pichico, Los Venados, Contrafuerte, El Zapallo, Futangue, Pitreño, Trahuico, Riñinahue Alto, Ranquil, Chanco, Epulafquén, Las Quemas, Licán, Boqueal, Rucatayo, and Mantilhue were evacuated; and areas in the Los Lagos Region such as , , , , and were also evacuated, increasing the number to at least 3,000 total evacuated people. It was reported that, at first, large land- and farm-owners in Chilean rural areas near the volcano did not allow workers to be evacuated. According to Chilean authorities, the evacuated persons "would be relocated in temporary shelters in safe areas." There are no reports of deaths or injuries.
The families who refused to be evacuated from the riverbed of Rio Nilahue were removed by force by the Carabineros de Chile after a resolution of the Appeal Court of Valdivia. It took the police more than 8 hours to evacuate 40 people. People resisted mainly because they had to leave their livestock behind. Small livestock farmers were permitted to check and care for their livestock once a day.
On June 17, 2011 OVDAS reported that the ash-and-gas plume reached 3 kilometres (1.9 mi) above sea level, and the frequency of earthquakes had dropped to 5 per hour. They reduced the alert level from 6 (moderate eruption) to 5 (imminent eruption), and at least 100 evacuated persons were allowed to return home. People from the Northeast side of the Cordón (Nilahue and Gol Gol Valley) will stay in the shelters.
On June 19 the ONEMI decided that all 4,200 evacuees could return home, as the scale of the eruption continued to decrease.
Ash cloud over Argentina and Uruguay
The ash cloud crossed Chile's borders and precipitated over the Argentine cities of Villa la Angostura, Bariloche and the northern part of Chubut province. The eruption was reported to have produced lightning and strong thunderstorms. Argentine Minister of Defense Arturo Puricelli ordered that "the Argentine Army personnel, means of transport, water treatment plants, and other equipment of VI Mountain Brigade in the province of Neuquén" be moved to the affected areas on the Argentine border with Chile.
In Argentina's affected cities, people have been recommended to stay indoors.
On June 5 the ash rain in Bariloche ceased. There were reports that the ash had caused power outages and prompted the local airport to be closed. The Bariloche Atomic Centre reported that the ashes contain no crystal phases of quartz or cristobalite.
On June 9 ash clouds from Puyehue reached Uruguay, forcing most flights to be cancelled. On June 11 the ash clouds reached the southern tip of New Zealand, with unusual sunsets reported in Invercargill.
River temperature and contamination
The eruption of the Chilean volcano Puyehue significantly affected the surrounding environment. The temperature of the Nilahue River rose to 45 °C (113 °F) and killed an estimated 4.5 million fish with an economic impact on fish farming in the area. The cattle economy was also damaged.
Scientists from the Southern University of Chile analyzed waters from the Nilahue and Golgol rivers, the two principal collectors of waters from Cordón Caulle. Scientists found that if solid particles were removed the water was safe to drink.
Livestock
The ash cloud led Argentina to declare a state of emergency for farmers as the prolonged eruption's continued effect on the 2 million head of sheep that graze in southern Argentina. Chubut and had suffered five years of drought, and the ash destroyed the little pastureland still serviceable. 750.000 sheep suffered the consequences, and Rio Negro officials said 60,000 head of cattle also were "at risk."
Transport disruption
Ash poses a significant threat to aircraft because once sucked into engines, it can be transformed into molten glass by the high temperatures and potentially cause an engine to fail.
On the ground lava, but also ash and volcanic stone can impede the vehicle movement.
Chile
Initially, because of the wind direction (to east), the flights whithin Chile were not interrupted and only the highway Route 215-CH and the "Cardenal Samore Pass" was reported to be covered by 10 to 15 cm of "volcanic stone" by Chilean authorities. and closed down on June 4.
The Chilean government increased the frequency of barges on the Pirihueico Lake in Huahum Pass to transport passengers traveling between Chile and Argentina. Huahum Pass is approximately 100 km north of the closed "Cardenal Samore Pass".
On June 22, as the ash cloud rounded the world und "returned" to Chile, the Chilean airline LAN cancelled flights to Temuco and Valdivia in the south of the country.
Argentina, Uruguay and Brazil
On June 4 at approximately 4:30 pm local time, Neuquén Airport was closed due to the ash cloud. Ash fell across a wide swathe of South America, forcing cancellation of most flights across the southern half of the continent. A planned meeting between the presidents of Argentina and Uruguay was cancelled because José Mujica was unable to fly to Buenos Aires.
South Brazil suffered a lot with flights between Buenos Aires, Montevideo, Santiago, Curitiba, Florianopolis and Porto Alegre cancelled.
Falkland Islands
Three Falkland Islands air links with the United Kingdom were merged onto one aircraft. Allocation operated according to a priority system, with passengers ranked in importance. The three highest categories were 1. Travel for medical reasons (as designated by the Director of Health and Education); 2. Students returning to study (as designated by the Director of Health and Education); 3. Business passengers at risk of a serious and unavoidable impact on their business. Passengers were strongly recommended to travel LAN Airlines as the ash cloud did not cover the route over Punta Arenas.
South Africa
On June 14 the South African Civil Aviation Authority released a statement saying that the ash cloud was being monitored and that there was no operational impact to the airlines, however, two local airlines, South African Airways and Kulula.com, cancelled some flights to and from Cape Town International Airport and East London Airport on June 18; operations later returned to normal,
Australia and New Zealand
At its greatest extent, strong winds had carried the ash cloud from Puyehue a great distance at high altitude, and the ash remained present for several days at distinct altitude bands between 20,000–35,000 feet over New Zealand and southern Australia, disrupting flights between Adelaide, Melbourne, Perth, and all of Tasmania and New Zealand. Initially Air New Zealand managed to avoid cancellations by flying their aircraft at lower altitudes (20,000 feet) in order to avoid ash, requiring 10% more fuel. Cancellations started by June 15.
Virgin Australia resumed flights to southern Australia by June 13, but Qantas and its subsidiary Jetstar did not resume flights until June 14 and 15 because the Volcanic Ash Advisory Centre in Australia did not have the technology to determine the thickness of the plume. Losses for the airlines are expected to be in the millions.
Flights to and from Perth were disrupted by the approaching plume of ash, extending from 15,000 to 35,000 feet.
On June 20 flights were once again cancelled at Adelaide and Mildura airports. On June 21 and 22 flights to Sydney, Canberra, Melbourne, Newcastle, Wagga Wagga and Albury airports were cancelled due to the ash cloud. As of 22 June 2011 the ash cloud was expected to move from Australia to New Zealand.
Economic and financial impact
Macquarie Equities placed the cost of disruptions to airlines at AU$21 million for Qantas and $11 million for Virgin Australia. The tourism industry was also impacted, costing AU$15 million during the two-week period, with CEO John Lee of lobbying group Tourism & Transport Forum stating a daily cost of at least AU$10 million as a result of complete closure of Sydney and Melbourne's main airports.
The government of Neuquen province, Argentina, declared an economic emergency as the ash cloud was harming tourism and threatening livestock. The decree by provincial governor Jorge Sapag allowed those affected to claim for tax and other benefits. In Argentina ashes from Puyehue were advertised for sale and some were also used for making handicrafts. The intendant of Villa La Angostura asured that there were plenty of ideas of what to do with the ashes, among them bricks. In addition ashes were used to improve gravel roads around San Carlos de Bariloche.
See also
References
External links
- OVDAS reports
- Chile's Volcano Erupts: Crazy Skies — slideshow by Life magazine
- Volcanic Ash and Pumice From Puyehue, slideshow from The Atlantic, Jun 17, 2011
Retrieved from : http://en.wikipedia.org/wiki/2011_Puyehue-Cord%C3%B3n_Caulle_eruption
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