[2] At least 3,500 people were evacuated from nearby areas,[3] while the ash cloud was blown across cities all around the Southern hemisphere, including Bariloche, Buenos Aires, Montevideo, Stanley, Porto Alegre, Cape Town, Hobart, Perth, Adelaide, Sydney, Melbourne, Wellington, Auckland and Port Moresby, forcing airlines to cancel hundreds of international and domestic flights and causing travel chaos.

The Chilean civil aviation authority 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.

[4] An estimated one hundred million tons of ash, sand and pumice were ejected – requiring power equivalent to 70 Hiroshima atomic bombs.

[5] Cordón Caulle is a volcanic fissure and has erupted many times in recorded history, most recently in 1960, following the 1960 Valdivia earthquake days earlier,[6] whereas the Puyehue stratocone has remained dormant.

[11] 18 days after it first erupted, lava begun spilling from the volcano, heading west and flowing "slowly by a channel about 50 meters wide and 100 feet long.

[5] Evaluation of the total amount of airborne erupted material has proved to be challenging, with estimated values ranging from 0.5 to 1.5 km3 (0.12 to 0.36 cu mi).

[14] 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 El Retiro, Anticura, El Caulle, Forestal Comaco, and Anticura Pajaritos were also evacuated, increasing the number to at least 3,000 total evacuated people.

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.

[18] On 17 June 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.

[21] The ash cloud crossed Chile's borders and precipitated over the Argentine cities of Villa la Angostura, Bariloche and the northern part of Chubut[22] province.

Whereas there appears to be no published support for the existence of heart attacks or throat cancer as a consequence from the exposure to ashes and causing death, there are at least two phenomena which play a role.

Initially, because of the wind direction (to east), the flights within 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.

[45] The Chilean government increased the frequency of barges on the Pirihueico Lake in Huahum Pass to transport passengers traveling between Chile and Argentina.

On 22 June, as the ash cloud rounded the world and returned to Chile, the Chilean airline LAN cancelled flights to Temuco and Valdivia in the south of the country.

[48] South Brazil suffered a lot with flights between Buenos Aires, Montevideo, Santiago, Curitiba, Florianopolis and Porto Alegre cancelled.

[49] On 14 June 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.

[51][52] 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.

[58][59] Subsequently, Rob Fyfe of Air New Zealand hit back at malicious rumours from Australian airlines that continuing to fly was unsafe.

[70] The government of Neuquen province, Argentina, declared an economic emergency as the ash cloud was harming tourism and threatening livestock.

[72] The president Cristina Fernández announced on national television plans to supply $2.41 billion to 1,400 farmers and businesses in the area affected by the ash cloud.

They also plan to spend $7 million on the cleanup operation, and double social benefits, and defer tax payments for the hardest hit regions.