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The Mount Mayon volcano in Albay. Credit: @phivolcs_dost
Thousands of people have been forced into emergency shelters by an active volcano in the Philippines, with warnings a “hazardous eruption” could happen in days.
Officials raised the alert level around Mount Mayon in Albay province to critical after it spewed ash thousands of metres into the air and magma could be seen glowing in the crater.
The first “steam-driven eruption” started at around 5pm local time on 13 January, with the Philippine Institute of Volcanology and Seismology recording an ash column 2,500 meters high.
Two further eruptions have since been recorded, with villagers reporting a sulphurous smell and rumbling sound.
In a statement, the institute said: “Mayon is exhibiting relatively high levels of unrest and that magma is at the crater and that a hazardous eruption is possible within weeks or even days.”
Residents have been urged to protect against inhaling the ash by wearing masks or covering their noses and mouths with damp cloths.
Given the increasing danger, officials have recommended that a “danger zone” of a 7km radius be enforced “due to the danger of rockfalls, landslides and sudden explosions or dome collapses that may generate hazardous volcanic flows”.
Deadly cold lava flows or “lahars” may also be triggered.
People living outside the danger zone have been warned to take precautions against potential roof collapses due to the weight of ash and rainfall.
Mayon last erupted in 2014, with lava flows forcing thousands of people to evacuate.
It was most deadly in February 1841, when 1,200 people were killed and lava buried a town.
Experts say it has been displaying abnormal behaviour since late last year.
Courtesy of Sky News
Hot spots on Erta Ale – the reported flank eruption is not (yet) visible (MODIS data, Univ. Hawai’i)
News have come in about a fissure eruption at the SE flank of the volcano, approx. 7 km distance from the summit caldera and its lava lake (which partially collapsed on and after 20 Jan).
According to our local correspondents, the activity at the summit has decreased a lot, which would be in accordance with the scenario of lava now being drained through lower fissures on the flanks. Apparently, the fissures opened on or shortly after 21 Jan and produce large amounts of lava now flowing into the direction of Afdera.
Courtesy of volcanodiscovery.com
Stromboli’s crater terrace this morning with glow from the central vent (image: INGV Catania Pizzo webcam)
The activity at the “Lighthouse of the Mediterranean” has been much more intense recently than during most of the year.
Explosions mainly from the eastern vent (towards Stromboli village) have been observed at intervals of approx. 10 minutes, ejecting dense jets of incandescent lava to up to estimated 150 m height.
Continuous glow can be seen from adjacent vents in the central crater area as well, suggesting a relatively high lava column inside the conduit.
Courtesy of volcanodiscovery.com
Hot spots on Erta Ale (MODIS data, Univ. Hawai’i)
Activity remains elevated at the volcano in the Danakil. The latest available information show simultaneous effusive activity from both the north and the south crater – the latter, which contained the famous lava lake has been overflowing and building a new lava shield that started to partially fill the summit caldera.
It seems that lava flows have started to overflow even outside the caldera through the low part of the rim on the NE side (judging from satellite data).
Courtesy of volcanodiscovery.com
Just below millions of people there is a supervolcano that has begun to show signs of reawakening. The supervolcano, Campi Flegrei, is 8 miles wide and sits beneath the Bay of Naples offshore Italy. Recent monitoring of the volcano points to a reawakening of one of the largest volcanoes in Europe.
An international team of geoscientists have monitored the volcano’s caldera for signs of activity and recently published results in the journal Nature Communications on the increased danger of an eruption.
Campi Flegrei, which means “burning fields” in Italian, is believed to have formed hundreds of thousands of years ago and has erupted on several occasions in recent geologic time. The initial eruption, which occurred 200,000 years ago triggered a “volcanic winter” from the massive amount of ash ejected into the atmosphere. The volcano then erupted again 40,000 and 12,000 years ago.
The eruption 40,000 years ago is thought to have wiped out most of the European Neanderthals and was one of the largest volcanic eruptions of all time. In recent memory, Campi Flegrei erupted in 1538 for 8 days straight, sending ash across Europe and forming the new mountain Monte Nuovo.
Recent measurements from the Campi Flegrei volcano indicate it is approaching what is called the critical degassing pressure (CDP), a pressure at which the volcano can begin a phase of volatility and volcanic unrest. The CDP is generally speaking a pressure where volcanic gas can release from the underlying magma, heat localized hydrothermal vents, fluids, and rocks. This increased pressure and heat can trigger deformation of the overburden rock and ultimately rock failure, i.e. a volcanic eruption.
Scientists have measured accelerated deformation of the volcano, which has literally risen recently due to increased gaseous pressures. Scientists have measured a 1.25 feet rise of the volcano’s ground since 2005. Gas at high pressures in the subsurface is exceptionally dangerous as it can easily and quickly lead to an unconstrained positive feedback loop. Imagine gas in solution in magma, which is relatively stable.
If that gas begins to escape and rise in the Earth’s subsurface through magma, the gas will subsequently reduce the overlying pressure of the magma below it. That in turn allows for more gas to come out of solution and rise in the magma column. In an instant, you can have a runaway situation whereby decompressed gas allows for more decompression and an eventual blowout. This is not dissimilar to some situations seen during oil and gas well blowouts.
The location of Campi Flegrei is especially alarming, located immediately near the metropolitan area of Naples, a very densely populated metropolitan area. The volcano is therefore actively monitored by the Italian National Institute of Geophysics located in Rome, where real time measurements are analyzed for increasing threat.
Despite the increasing signs of activity, it’s very hard to determine the “tipping point” at which the volcano begins erupting. However, the Italian government recently raised the volcano’s threat level from green to yellow, which requires constant scientific monitoring for changes in volcanic behavior. The most common signs of increased likelihood of an eruption are increased gas output (decreased gas pressure), elevation rise on the volcano’s surface, and increased seismicity within the volcano.
Unfortunately, the best thing we can currently do is actively monitor the volcano for signs of further increasing activity. However, an eruption could not happen for the next century, it’s impossible to accurately model when these events will occur. Similar to many geologic processes on Earth (earthquakes, volcanic eruptions, sinkholes, etc.) the signs of decreasing stability are easy to detect but the tipping point at which the event occurs is very hard to predict.
Courtesy of chiangraitimes.com