Volcanoes


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Lokon-Empung volcano in Indonesia shaken by violent eruption

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An explosion occurred Wednesday (20 May) at 15:22 local time and produced an ash plume of approx 1.5 km height. The eruption was accompanied by strong explosion sounds, which caused concern in nearby villages and the town of Tomohon. After the initial explosion, mild ash venting continued for a while. The eruption came from two vents, both the Tompaluan crater and the new crater west of it that had formed in October last year.

Megaphone

Hear Costa Rica's Turrialba volcano rumble

Ever wondered what the inside of a volcano sounds like? The Volcanological and Seismological Observatory of Costa Rica (OVSICORI) has you covered.

OVSICORI took a selection from a seismograph registered inside Turrialba Volcano's central crater and converted it into a sound file. The effect allows you to "hear" the volcano's sub-audible rumbling.

This particular example was mostly for fun, but Dr. Javier Pacheco, a seismology expert at OVSICORI, said that the technique had practical uses for scientists too. Converting the seismographs into audio files can help scientists identify variations in the frequency of seismological activity that would be difficult to identify visually from the readouts alone, he explained.

Turrialba Volcano has been active during the last several months, closing Juan Santamaría International Airport several times after large eruptions of ash that blew across the Central Valley.

Volcanologists expect that the eruptions will get more frequent and more violent in the coming months and the National Emergency Commission (CNE) has maintained a yellow alert in the area. The Commission recently expanded the evacuation zone around the volcano from 2 km to 5 km.


Bizarro Earth

Hawaiian volcano on brink of eruption

© Thinkstock
Kilauea, on the Big Island of Hawaii, is one of the more active shield volcanoes in the Aloha State and observers at the United States Geological Survey are saying that the odds of a major eruption have increased significantly in recent days.

"Activity at the summit of Kīlauea Volcano continues to change, as shown by a pronounced drop in the level of the lava lake within Halemaʻumaʻu Crater, a change in the summit area deformation pattern, and the concentrated earthquake activity in the southern part of the caldera and upper Southwest Rift Zone," a recent statement from the USGS said.

A lake of molten rock near the summit of the volcano had risen to record-high levels, but, as the USGS statement pointed out, the lava level has subsided, dropping almost 500 feet. As lava levels have been rising and falling, a series of earthquakes have radiated out from Kilauea.

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Second eruption in 2015 at Piton de al Fournaise volcano

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A new eruption, so far small, began this Sunday at 13:45 from a fissure vent at the the southeast slopes of the Dolomieux crater inside the Enclos next to the Château Fort cone.

An intense seismic crisis with 5-7 earthquakes per minutes started 55 minutes before the onset of the eruption, as magma pushed its way to the surface. A few minutes after the beginning of the quakes, significant deformation of the Dolomieu crater rim could be measured as well.

The prefecture of La Réunion triggered alert phase 2 and closed access to the Enclos.

The new eruption seems to be similar in its (small) size and vent location as the last one that occurred between 4-16 February this year. Both probably originate from a same shallow magma reservoir that by early 2015 had grown enough to produce eruptions at the surface.

Frequent (several per year), but generally small eruptions have been a typical feature of Piton de la Fournaise during much of the volcano's recent past decades.

Comment: Reports of eruptions and volcanic activity since May 1:




Red Flag

Scientists: Series of earthquakes could signal new eruptions at Hawaii's Kilauea volcano

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© AP/Cathy Bussewitz
A series of earthquakes and shifting ground on the slopes of Kilauea have scientists wondering what will happen next at one of the world's most active volcanos.

A lake of lava near the summit of Kilauea on Hawaii's Big Island had risen to a record-high level after a recent explosion. But in the past few days, the pool of molten rock began sinking, and the surface of the lava lake fell nearly 500 feet.

Meanwhile, a rash of earthquakes rattled the volcano with as many as 20 to 25 quakes per hour, and scientists' tilt meters detected that the ground was deforming.

"Clearly the lava, by dropping out of sight, it has to be going somewhere," said Steven Brantley, deputy scientist in charge of Hawaiian Volcano Observatory of the U.S. Geological Survey.

One possibility is that a new lava eruption could break through the surface of the mountain, Brantley said.

Right now, there are two active eruptions on Kilauea. One is the eruption spewing into the lava lake in the Halemaumau Crater, which is visible in Hawaii Volcanoes National Park. The other is Puu Oo vent, in Kilauea's east rift zone, which sent fingers of lava toward the town of Pahoa before stopping outside a shopping center last year.

Bizarro Earth

Guatemala's Fuego volcano becoming more active, officials warn of full-blown eruption


Ash billowing from the Fuego volcano is seen from the Palin municipality, Escuintla departament, 40 km south of Guatemala City on February 13, 2015
Guatemala's Fuego volcano is becoming more active, belching out increasing amounts of smoke and ash, officials said on Friday.

Fearing a full-blown eruption of the volcano, located just 50 kilometers (30 miles) from the capital of Guatemala City, disaster officials warned that aircraft should exercise caution when flying over Fuego.

Conred, the national disaster coordination agency, said the volcano's eruptions could range in intensity from weak to moderate, and that columns of ash could reach 4,500 meters (15,000 feet) above sea level.

Authorities also warned that wind-borne ash particles could travel as far as 12 kilometers from the volcano, possibly causing respiratory and other health problems for some Guatemalans.

Comment: Volcanic eruptions and earthquakes increasing across the planet


Info

Scientists find volcanic activity can be induced by external noise

© Reuters / Sergio Candia
Volcanoes are considered chaotic systems. They are difficult to model because the geophysical and chemical parameters in volcanic eruptions exhibit high levels of uncertainty. Now, Dmitri V. Alexandrov and colleagues from the Ural Federal University in Ekaterinburg, in the Russian Federation, have further extended an eruption model—previously developed by other scientists—to the friction force at work between the volcanic plug and volcanic conduit surface. The results, published in EPJ B, provide evidence that volcanic activity can be induced by external noises that would not otherwise have been predicted by the model.

Attention

Telica volcano, Nicaragua's most active, spews fiery rocks, gases and ash; 30 eruptions reported

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© AFP
Nicaragua's Telica volcano, the country's most active, has spewed fiery rocks and gases, dusting nearby towns with ash.

The volcano has registered 30 small eruptions since it rumbled to life on Thursday, the strongest yet occurring on Sunday night, according to the Nicaraguan Geological Institute.

'It spat hot rocks, gas and ash, reaching a height of 400 metres,' the agency said in a statement.

The flaming rocks caused vegetation on the volcano's slopes to catch fire, and fiery balls of burning foliage created a spectacle for observers.

The nearby towns of Posoltega and Guanacastal were dusted in ash following the eruptions, though no major damage or injuries were reported.

Telica, which is 1,061 metres high, is located in the foothills of the Maribios, about 112km northwest of the Nicaraguan capital Managua.

Health

Turrialba Volcano erupts again - scientists warn of economic damage, increased health risks

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At 4:55 a.m. Sunday, ash spilled from the crater of Costa Rica's Turrialba Volcano for nearly an hour. Though the ash barely left the crater, located about 67 kilometer northeast of the capital San José, the wind carried it into the Central Valley — for the umpteenth time in recent months.

The eruption comes less than a week after the volcano shot a tower of ash 2.5 kilometers into the air, shutting down Juan Santamaría International Airport for the third time since March.

Since Turrialba Volcano re-awoke last October, volcanic ash has dirtied homes, damaged crops and mucked up travel plans. With its frequent eruptions, the volcano has gone from an interesting diversion to a nuisance for nearby residents and visitors.

And experts say the worst is yet to come.

Future eruptions, they say, could jeopardize the health of humans and the environment. They could also cause serious economic damage.

"There is a very high possibility that [the volcano] will reach a higher level of activity," said Lidier Esquivel, the chief investigator of risk management for the National Emergency Commission (CNE).

Scientists with both the Volcanological and Seismological Observatory of Costa Rica (OVSICORI) and the National Seismological Network (RSN) expect Turrialba's eruptions to gradually increase over the next few months until the volcano is erupting on a near weekly basis. Scientists have also confirmed that lava has reached the surface.

Attention

Experts warn Japan may have entered an era of great earthquakes and volcanic eruptions

Mt. Fuji is located only about 25 kilometers from Mt. Hakone. While Mt. Fuji is also an active volcano, will the increased volcanic activity of Mt. Hakone have any effects on Mt. Fuji?

"The magma chambers located beneath Mt. Hakone and Mt. Fuji are not connected, so there is no effect on Mt. Fuji," said Toshitsugu Fujii, who chairs the Japan Meteorological Agency's Coordinating Committee for Prediction of Volcanic Eruptions. The agency has not observed any signs of impending eruption in Mt. Fuji and therefore has not raised the eruption alert level for the mountain.

However, since the magnitude-9.0 Great East Japan Earthquake occurred in March 2011, volcanoes in the country have shown signs of increased activity. Currently, a Level 2 eruption alert, which restricts access around the volcanic vent, is in effect for 10 volcanoes, while a Level 3 alert, which restricts approach to the volcano, has been issued for three volcanoes.

Comment: Earthquake and volcanic activity has been on the rise worldwide and experts are predicting that we can expect that to continue in the near future.