After a short period of rest, the Villarrica volcano in southern Chile recently exploded to life again, sending a plume of boiling ash high into the atmosphere.
The eruption triggered an increase in the alert level near the volcano to orange, the second highest rating.

The 2860-metre-high snow-capped stratovolcano, located 750 kilometres south of the capital Santiago, is one of the most active in Chile.

The latest series of eruptions began on 7 February with several minor explosions and ash plumes triggering a yellow alert.

A further pre-dawn eruption on 3 March sparked the evacuation of thousands of people from within a 10-kilometre radius of the volcano.

That eruption covered the mountain's eastern flank with a huge volume of volcanic material.

Villarrica is one of Chile's most active volcanoes with at least 66 recorded eruptions since the arrival of Europeans.

This image of Villarrica's latest eruption was taken from an altitude of about 700 kilometres by the Advanced Land Imager onboard NASA's EO-1 satellite on 18 March, 2015.

Eric Worrall writes: The Guardian has published an unusually interesting article about the danger to our civilisation, of a new Tambora scale volcanic eruption.
According to Bill McGuire, professor emeritus of geophysical and climate hazards at UCL;

"In April 1815, the biggest known eruption of the historical period blew apart the Tambora volcano, on the Indonesian island of Sumbawa, 12,000km from the UK. What happened next testifies to the enormous reach of the biggest volcanic blasts.

The Tambora volcano had shown no signs of life for 1,000 years; a single eruption in the previous five millennia provided the only indication that magma was still churning far beneath. It is very likely that the residents of the island considered the volcano extinct, and possible even that they did not know the impressive 4,300m (14,107ft) mountain - at the time, probably the highest in the East Indies - was a volcano at all. This all changed, however, with the rumblings and earthquakes of 1812, a full three years before the climactic blast. Over time, the seismic shocks were superseded by steam blasts and small ash explosions, engendering increasing trepidation on the island and signalling that something bigger might be imminent. It was. On 5 April 1815, a titanic explosion hurled a cloud of ash to a height of more than 30km."
...

The consequences for the developed societies of the northern hemisphere were dire. A dry, sulphurous, fog draped itself across the landscape of eastern North America, causing temperatures to plunge and bringing unprecedented summer cold. In New York State, snow fell in June, while the bitter cold and killing frosts wiped out crops and halved the length of the growing season across much of the region. On the other side of the Atlantic, Europe saw summer temperatures down by 2C compared to the average for the decade; the unseasonal cold accompanied by incessant rains and - into the following winter - by unusually powerful storms. Analysis of climate records reveals that 1816, the so-called "year without a summer", was the second coldest in the northern hemisphere of the past six centuries."

Read the rest of the article here.

Strong explosions continue to occur. An eruption at 08:20 local time this morning produced several pyroclastic flows that traveled down the western flank of the volcano.

Citing increased seismic intensity, the U.S. Geological Survey is upgrading the volcano alert level status for Semisopochnoi, an Aleutian Island volcano, to "advisory," the agency said in a notice issued Wednesday morning.

Seismic activity at the Semisopochnoi volcano began in January, but "has increased in intensity over the past few days," USGS wrote in the notice. "In addition, we have detected brief periods of seismic tremor, which can indicate movement of magma or magmatic gases."

Semisopochnoi is remote even by Alaska standards. It lies on an island of the same name some 127 miles from Adak and 1,283 miles from Anchorage.

• The volcano erupted earlier this month, triggering evacuations of thousands of people, including tourists
• Residents in Pucon, a resort town near the volcano, were fearful that clouds of smoke could signal another eruption was on its way
• The March eruption was Villarrica's first major eruption since 1984

A steady stream of smoke and ash leaking from the Villarrica volcano has residents of a nearby town wondering if - or when - disaster might strike.

Chilean officials raised threat levels to orange on Wednesday due to increasing signs of activity in the 2840-meter tall volcano, leaving area residents fearful of an eruption.

'No one can sleep peacefully because the other day the eruption surprised us at 3 in the morning,' said Francisco Valenzuela, a tour guide in the nearby resort town of Pucon.

'The tourists are also a little uncertain,' Valenzuela said. 'Could something happen today? Could something happen tomorrow?'

The BBC reports that local authorities canceled classes for the more than 5,500 students in the area.

Many of the residents in towns and communities surrounding the volcano had to be evacuated earlier in the month, when lava and smoke erupted from the peak in the early hours of the morning.

'It was spewing lava and ash hundreds of meters into the air,' 29-year-old Australian tourist Travis Armstrong said. 'Lightning was striking down at the volcano from the ash cloud that formed from the eruption.'

The volcano continues to produce sometimes strong vulcanian-type explosions that seem to have picked up in strength over the past days.

An eruption at 03:08 am local time produced fountaining of lava several hundred meters high and appears to have caused a small pyroclastic flow.

Two new explosion of gas and ash Friday mid-morning broke a brief period of low activity at Turrialba Volcano, located in the province of Cartago, 67 kilometers from the capital San José.

The new explosions follow one that occurred at 4:30 a.m. Friday and four on Thursday.

The Volcanological and Seismological Observatory of Costa Rica (OVSICORI)'s web cameras recorded the explosions Friday. The agency reported that columns of material reached some 1,500 meters high (4,921 feet), similar to those recorded on Thursday.

Spewings of ash and gases lasted for periods of some 30 minutes, OVSICORI reported.

UPDATED at 7:00 p.m. with airport re-opening time.

Juan Santamaría International Airport will remain closed until at least 8:00 a.m. Friday, March 13, according to airport administration. Airport spokeswoman Silvia Chávez said that the Friday re-opening was conditional on overnight activity at Turrialba Volcano.

UPDATED at 5 p.m. with information on affected flights.

Falling ash from Costa Rica's Turrialba Volcano closed the country's Juan Santamaría International Airport on Thursday afternoon at approximately 4:00 p.m., according to airport management.

Two of Guatemala's three active volcanoes have now rumbled to life, officials said Wednesday, one day after the Santiaguito volcano began belching smoke and showering nearby towns with ash.

Guatemala's Fuego volcano, in the southwest, over the past several weeks has spewed adjacent towns with soot, forcing the temporary closure last month of a neighboring airport.

Now the Santiaguito volcano in the west has awakened as well, emitting columns of ash 400 meters (1,300 feet) tall above its crater.

Santiaguito, whose peak soars to 2,500 meters above sea level, is located in western Quetzaltenango province.

The sleeping giant began to stir on Tuesday, but officials said that thus far, they have not had to evacuate populated areas nearby.

The 3,700-meter tall Fuego — whose name means fire in English — last month spewed out large columns of ash, prompting an orange alert and forcing nearby residents to wear protective masks.

Volcano Villarrica in southern Chile erupted in the early hours of Tuesday, sending a plume of ash and lava high into the sky, and forcing the evacuation of nearby communities.

The volcano, located near the popular tourist resort of Pucon around 750 km (460 miles) south of the capital Santiago, is one of South America's most active. It last erupted in 2000.

A column of ash and rock particles shot up to 3 km (nearly 2 miles) into the sky overnight. Although the initial violent eruption was short-lived, intermittent clouds of steam and gas continue to issue from the volcano.

A major lava flow is not expected, said Luis Lara, head of national geological service Sernageomin on Tuesday morning, but that could change.

"After an eruptive pulse, which was pretty intense but very short at 3 am, the volcanic system remains unstable and it is possible that something similar could occur again in the next few hours," he said.

Some 3,385 people had been evacuated as a preventative measure, said Interior Minister Rodrigo Penailillo. There were no reports of any injuries.