PUERTO MONTT, Chile (AP) — Twin blasts from the Calbuco volcano in southern Chile sent vast clouds of ash into the sky, increasing concerns the dust could contaminate water, cause respiratory illnesses and ground more flights. 
 
 This photo provided by NASA’s Earth Observatory shows an image taken by the Moderate Resolution Imaging Spectroradiometer on NASA’s Terra satellite of an ash plume coming from the Calbuco volcano in Chile,... (Associated Press) 
 
 People evacuate the town of Ensenada, Chile after the Calbuco volcano erupted Thursday, April 23, 2015. The volcano erupted Wednesday for the first time in more than 42 years, billowing a huge ash cloud... (Associated Press) 
 
 A woman holds a mask to her face as she stands with her belongings before evacuating the town of Ensenada, Chile after the Calbuco volcano erupted, Thursday, April 23, 2015. The volcano erupted Wednesday... (Associated Press) 
 
 Footprints from humans and animals are left behind in the ash spewed from Chile's Calbuco volcano in Villa La Angostura in southern Argentina, Thursday, April 23, 2015. The volcano erupted Wednesday afternoon... (Associated Press) 
 
 Men remove ash from a building's roof, left by the Calbuco volcano, in Ensenada, Chile, Thursday, April 23, 2015. The volcano erupted Wednesday for the first time in more than 42 years, billowing a huge... (Associated Press) 
 
 ALTERNATE CROP - Children watch the Calbuco volcano erupt, from Puerto Varas, Chile, Wednesday, April 22, 2015. The volcano erupted billowing a huge ash cloud over a sparsely populated, mountainous area... (Associated Press) 
 
 The Calbuco volcano erupts near Puerto Varas, Chile, Thursday, April 23, 2015. The volcano erupted Wednesday for the first time in more than 42 years, billowing a huge ash cloud over a sparsely populated,... (Associated Press) 
 
 A car is covered in ash, left behind by the eruptions of the Calbuco volcano, in Ensenada, Chile, Thursday, April 23, 2015. The volcano erupted Wednesday for the first time in more than 42 years, billowing... (Associated Press) 
 
 The volcano erupted Wednesday afternoon for the first time in more than four decades, spewing out a plume of ash more than 6 miles (10 kilometers) high. Emergency officials were taken by surprise and had only a few minutes to issue an alert. 
 
 Calbuco had another spectacular outburst early Thursday with lightning crackling through a dark sky turned reddish orange by the explosion. 
 
 As the ash cloud spread Wednesday, "people went into a state of panic," said Miguel Silva Diaz, an engineer who lives in Puerto Montt, a city about 14 miles (22 kilometers) from the volcano. "Then, at around 1 a.m., I heard a loud noise, as if somebody had detonated an atomic bomb." 
 
 No injuries were reported and the only person reported missing since the eruption was located Thursday. 
 
 Authorities evacuated 4,000 people as gas and ash continued to spew, and they closed access to the area around the volcano, which lies near the cities of Puerto Varas and Puerto Montt, some 620 miles (1,000 kilometers) south of Santiago. 
 
 "I was shocked. I had just arrived home when I looked through the window and saw the column of smoke rising up. We called our families, posted photos," said Daniel Palma, a psychologist who lives in Puerto Varas. 
 
 "We woke up today with a blanket of fog and it hasn't cleared. We have a layer of smoke above us," Palma said, adding that many were concerned about the possible effects of the ash on their health. 
 
 The Chilean national geology and mining service warned that people should prepare for a third and "even more aggressive eruption." 
 
 President Michelle Bachelet declared a state of emergency, saying the eruption of Calbuco was "more serious and unpredictable" than the one last month at the Villarica volcano, which also forced the evacuation of thousands. 
 
 "We don't have any problems with supplies, water or sewage up to now. That's not the problem," said Bachelet, who visited the area Thursday. "Our problem is a respiratory one, from inhaling all of this ash, and the fact that this ash could generate some sort of environmental contamination." 
 
 The short-term dangers related to the ash also include eye and skin infections as well as water contamination, said Bernardo Martorell, a physician and the head of the sanitary planning division at Chile's health ministry. 
 
 "That's why the people in the area need to evacuate," Martorell said. 
 
 Ash continued to fall Thursday in Puerto Montt and other nearby cities, said Patricio Vera, director of a local radio station. Vera said that after the initial eruption, hundreds of people rushed to buy gasoline, forcing stations to ration sales, while supermarkets closed early to avoid the risk of looting. 
 
 The 6,500 foot (2,000-meter) Calbuco last erupted in 1972 and is considered one of the top three most potentially dangerous among Chile's 90 active volcanos. 
 
 LATAM and other airline companies cancelled flights to and from Puerto Montt because airborne ash can severely damage jet engines. 
 
 In 2011, a volcano in the Caulle Cordon of southern Chile erupted violently, forcing the cancellation of hundreds of flights and the evacuation of more than 3,500 people. Thick, abrasive soot coated slopes in the ski resort city of San Carlos de Bariloche, over the border in Argentina. 
 
 By Thursday afternoon, much ash had made its way to Villa La Angostura, Argentina, a small town about 56 miles (90 kilometers) northeast of Calbuco. Cars and streets were coated with a thin layer of ash, but people were otherwise going about their business. 
 
 "We are praying that the volcanic activity will be as short as possible," said mayor Roberto Cacault. 
 
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 Associated Press writer Luis Hidalgo reported this story in Puerto Montt and Luis Andres Henao reported from Santiago. AP writers Gonzalo Keogan in Villa La Angostura, Argentina, and Eva Vergara in Santiago contributed to this report. 
 
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 Luis Andres Henao on Twitter: https://twitter.com/LuisAndresHenao 

 A missing hiker was found alive late Thursday as ash from Chile's Calbuco volcano continued to fill the air, piling on roadways and closing borders in the region. 
 
 The volcano first erupted Wednesday, marking the first such activity in more than 42 years, billowing a huge ash cloud over the sparsely populated, mountainous area in southern Chile. 
 
 Calbuco's second blast overnight was stronger and lasted longer 
 
 A second, more powerful eruption hit around 1 a.m. Thursday, creating swarms of lightning storms. Stunning photos captured the phenomenon, known as “dirty thunderstorms,” which illuminated the night sky. 
 
 The eruption rained down as much as 15 to 20 inches of ash in the nearby town of Ensenada, officials said, closing schools and canceling flights. Several surrounding towns, including Alerce, Colonia Rio Sur and Correntos, were also evacuated. 
 
 About 7 p.m. local time, two earthquakes associated with fracturing of rock occurred. The largest happened less than 3 miles east of the main crater, with a magnitude of 3, officials said in a 9 p.m. update. An additional "minor" eruption is possible, officials said. 
 
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 The volcano could erupt again, possibly within hours, officials say 
 
 The country’s National Service of Geology and Mining said Thursday that the region remains on red alert, meaning there could be a third eruption within hours. President Michelle Bachelet has warned the volcano could soon emit lava. About 5,000 residents were evacuated, and towns within a 13-mile radius of the volcano were declared "exclusion zones." 
 
 No injuries or deaths were reported. A mountain climber reported missing earlier had been found, officials said. A government spokeswoman identified the hiker as 21-year-old Waldo Flores. Interior Undersecretary Mahmud Aleuy tweeted that Flores had been found by a local. He was then taken to a hospital to be checked, the spokeswoman said. 
 
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 Calbuco had been dormant for more than 40 years 
 
 According to the Associated Press, the Calbuco volcano hasn't erupted since 1972. It erupted violently and without warning Wednesday afternoon, sending a massive column of ash and smoke into the air. 
 
 Chile's president has declared a state of emergency 
 
 President Bachelet declared a state of emergency and was scheduled to travel to the region Thursday. 
 
 Officials said they did not anticipate any water, food or fuel shortages. Volcanic ash can contain heavy metals and toxic substances such as arsenic. According to a statement from the Ministry of the Interior, the region draws its drinking water from underground sources. 
 
 If lava begins to flow, however, it could melt snowpacks in the region and bring the threat of landslides or rising rivers to surrounding towns. 
 
 #LosLagos: AHORA, maquinaria de Vialidad trabaja en despeje de Ruta Ensenada - Petrohué y en otros puntos pic.twitter.com/iOVvSxXGk9 #Calbuco — Min. Obras Públicas (@mop_chile) April 23, 2015 
 
 Crews equipped with large machinery worked to clear roadways of piles of soot and ash, photos showed. Military forces have been sent to the region to keep order and guard against looting. 
 
 The government has issued a health advisory within the 13-mile radius of the volcano, and officials plan to distribute 46,000 face masks to area residents to combat the ash. 
 
 Ash fell nearly 70 miles away 
 
 Volcanic ash was falling in the Argentine resort city of Bariloche, about 68 miles east of Calbuco, the Associated Press reported. Officials there were analyzing the ash to see if it posed a threat to drinking water. 
 
 Officials closed several border crossings between Argentina and Chile, after "poor environmental conditions" made the roads impassable. 
 
 In 2008, the Chaiten volcano in Palena province erupted, forcing the evacuations of thousands and sending ash as far away as Buenos Aires, the Argentine capital more than 900 miles to the northeast. 
 
 UPDATES 
 
 7:14 p.m.: This story has been updated with information about earthquakes following the eruption. 
 
 4:23 p.m.: This article was updated with information that a missing hiker had been found alive. 
 
 11:17 a.m.: This article was updated throughout with additional details about a missing hiker and the state of emergency. 
 
 The first version of this article was published at 9:49 a.m.
– Southern Chile is on red alert after twin eruptions of the Calbuco volcano, with authorities warning that a third and "even more aggressive" eruption could be imminent. Two earthquakes, the bigger of which had a magnitude of 3, occurred in the area last night, reports the Los Angeles Times. The volcano's first eruption in 42 years produced some spectacular images, but it has also produced vast clouds of ash that authorities fear could contaminate water and badly disrupt aviation, as well as cause health problems, the AP reports. The ash has already coated the streets of cities more than 50 miles away in Argentina and caused the border to be closed in several places, according to the AP. Thousands of people have been evacuated from a 13-mile exclusion zone around the volcano, though the area is relatively lightly populated and there have been no deaths or injuries reported, the Times notes. A missing hiker was found alive yesterday.