Saturday, May 28, 2016

[Geology2] Volcano News 05.28.2016

Lava-loving tourists flock to active Nicaragua volcano

May 27, 2016 by Blanca Morel
A tourist takes pictures of a lava lake inside the crater of the Masaya Volcano in Nicaragua

Centuries ago, a native Central American people terrified of a witch believed to live deep in the earth used to sacrifice children and young women to Nicaragua's Masaya volcano.

Today, the crater southwest of the capital Managua is an international tourist magnet, where photo-snapping visitors scramble among sulfurous fumes to get views of its bubbling lava—a rare sight.

The only volcanoes in the world to boast lakes of incandescent magma are Masaya, Hawaii's Kilauea and Nyiragongo in the Democratic Republic of Congo, explained a Nicaraguan geographer and environmentalist, Jaime Incer.

"It's something extraordinary, unique in the world," said Noheli Pravia, a French visitor filming and photographing the scene which has happened every 20 to 25 years since 1902.

The red-hot liquid performs an agitated ballet for the spectators, with a cloud of white smoke filling the active crater, whose name is Santiago.

Masaya volcano is located in the most populated part of Nicaragua's Pacific coastal stretch and is inside a nature reserve of some 50 square kilometers (20 square miles) where vast fields of petrified lava contrast with the white flowers of frangipanis.

The 400-meter (1,300-foot) high volcano formed 5,000 years ago, and its activity has intensified in the past six months.

"This is the first time I've seen something like this—it's really impressive," said Mijaela Cuba, an Austrian nurse, speaking above the waves of lava.

Hundreds of tourists arrive daily to observe the lava flow which formed six months ago near the surface of the crater of the small Masaya volcano, one of the most active in Nicaragua

Toxic gases

She was one of 4,000 tourists whom the Nicaraguan government has given permission to edge up close to the crater's edge in the past two weeks. Each visit is limited to just a few minutes because of the risk from the .

The only signs of life in the walls of the crater, that go down hundreds of meters, are green parrots and bats.

Masaya has erupted twice in recorded history: in 1670 and 1772, scaring the Spanish conquistadors.

Each tourist's visit to the volcano is limited to just a few minutes because of the risk from toxic gases

"It is a maw of fire that never ceases to burn," the first governor of the region, Pedrarias Davila, wrote to the king of Spain in 1525.

One monk, Francisco de Bobadilla, even considered it to be the gate to hell and erected a big cross on the edge of the crater.

The pre-Columbian people who inhabited the area believed that a subterranean witch they called Chalchihuehe lived inside, and they sacrificed young innocent lives to try to appease her.

According to Incer, the risk now is that, if the lava keeps rising higher inside the volcano each time it appears, a new eruption could occur within the next 150 years on the scale of the one in 1772—when it reached as far 30 kilometers away, where today stands Nicaragua's international airport.


Why do people still live next to an active volcano?

May 26, 2016

Dedi Sinuhaji / EPA


Coventry University

Coventry University provides funding as a member of The Conversation UK.

The latest eruption of Mount Sinabung in Sumatra killed seven people and injured two others. After lying dormant for 400 years, Sinabung has erupted several times since 2010 and is now Idonesia's most active volcano. Locals have maintained a close watch as the official alert status has fluctuated, and thousands had already been evacuated long before the eruption.

But many villagers remained in the area – and outsiders may well wonder why, given the volcano's recent history, people would not only live near the "red zone" (the restricted area within 3km of the summit) but also regularly venture into it. Surely local people know the risks of a "pyroclastic" cloud of superheated gas?

This is a question we've looked at in our research. The recent large eruption had an added personal component – we were leading a team that had been investigating why people continued to live near the red zone. Our researchers had been distributing questionnaires and conducting interviews in the village of Gamber and other villages bordering the red zone right up to the previous Tuesday, May 17.

On several occasions, smaller eruptions sent huge plumes of superheated gas into the sky as well as down the slopes of the mountain towards inhabited villages. We were cautious – we monitored the situation closely and were ready to evacuate quickly if we needed to. We witnessed these eruptions with a mixture of excitement, awe and fear. This contrasted with the calm and – sometimes – complete indifference of locals.

Sinabung rumbles away in Jun 2015…but local farmers appear unconcerned. Dedhi Sahputra / EPA

The main eruption on May 22 sent a pyroclastic flow 4.5kms down the mountain, eventually reaching Gamber. Our experience in the field and knowledge of the devastating effects of other eruptions and natural hazards in Indonesia – such as the eruption of Mount Merapi in 2010 – meant that the latest tragic deaths were, sadly, not a surprise to us.

Villagers regularly go into the red zone to farm their land, for instance. But the villages themselves can face the additional risk of "lahars": potentially torrential flowing mixtures of water and rock fragments caused by heavy rainfall on the mountain. In the second week of our fieldwork, two children and one adult had been killed and a further child and adult were missing as a result of lahars not far from Gamber.

What next for communities around Sinabung?

While we are not yet ready to report on people's thoughts and actions in the week prior to the latest eruptions, there are some preliminary answers. Previous research tells us the key factors explaining why people live in these dangerous situations are attachment to place and the protection of their livelihoods as well as a capacity to adapt to natural hazards and the reduced perception of risk that involves.

A recent review by the International Federation of Red Cross and Red Crescent Societies highlighted the need for external agencies and organisations to set aside their own conceptions of risk and engage seriously with the "alternative rationalities" of local people. Considerations about whether to stay, relocate independently or be relocated by the government to other locations should reflect the priorities of villagers and their community identities.

In the case of Gamber and other villages like it, many are reluctant to leave land owned by generations of ancestors as long as they can also continue to make a living from it. And, while people may not seem to fear being injured or killed by an eruption, we heard that some are less likely to visit their land within the red zone when there are no volunteer observers from a local group watching the mountain.

Our research at Mount Sinabung also tells us that people who have been permanently relocated from the red zone to new villages far from the mountain appear to have a better quality of life and less risk of health problems from dense ash clouds, for instance. In contrast, many people who have been temporarily evacuated to shelters (known as "Posko") are in a desperate situation. They live in poor conditions with few offers of work and concerns about the quality of government-provided food. Some have now lived like this since 2010.

Villages outside the red zone have been designated safe by authorities but regular ash falls affect their health and reduce their ability to maintain farmland. For some, the ongoing eruptions will probably mean that their status as "refugees" will change soon.

View from a village next to the red zone. Gavin Sullivan, Author provided

In this context, what impact can our research hope to have? Cultural change might occur by, for example, educating young people about the risks and encouraging them to change the activities of their parents. And we hope to provide evidence of how living so close to a volcano affects the psychology, health and well-being of villagers. This will turn, allow related interventions to be developed.

Our findings may also demonstrate the importance of community-led initiatives, such as volunteer groups formed of local villagers, in facilitating communications with authorities about imminent threats and the need to evacuate. Living near the volcano is dangerous and complicated but support and solutions are possible.


Phreatic danger still lurks in quiet Mayon Volcano — Phivolcs

by Philippine News Agency
May 27, 2016

By Catherine J. Teves

World-famous Mayon Volcano's quiet demeanor at present can be deceiving.

"Phreatic eruptions are still possible there," warned volcanologist Gerald Malipot from State-run Philippine Institute of Volcanology and Seismology (Phivolcs).

Mayon Volcano (MB file photo)

Mayon Volcano (MB file photo)

He noted such potentially deadly eruptions mostly occur without warning so it's best for people to avoid entering Mayon's six-kilometer radius permanent danger zone (PDZ) even if alert level for this volcano is zero at present.

"A deadly phreatic eruption occurred there on May 7, 2013 when Mayon was also at zero alert level," he recalled.

National Disaster Risk Reduction and Management Council (NDRRMC) reported such eruption lasted for about 73 seconds and killed five people who were within Mayon's PDZ at the time.

NDRRMC said the eruption also injured nine people.

According to experts, phreatic eruptions are steam-driven blasts that occur when water beneath the ground or on the surface transforms into steam after coming into contact with hot volcanic materials.

Phivolcs volcanologist Winchelle Sevilla earlier said there's still no means for giving advanced warnings about looming phreatic eruptions as research into this matter is going on.

"People must therefore avoid entering Mayon's PDZ," he said.

Rising some 2.46 kilometers above sea level, Mayon Volcano in Albay province has gained international fame for its near-perfect cone.

Phivolcs noted Mayon is among the Philippines' active volcanoes.

Malipot said Mayon was previously at alert level one as Phivolcs monitored low-level unrest there then.

Mayon's alert level has been zero since early February 2016 as Phivolcs' monitoring indicates minimal volcanic activity there, he said.

Zero alert level indicates Mayon is "quiet" and manifesting no imminent magmatic eruption, he added.

"Even at zero alert level, however, the risk for phreatic eruptions there remains," he clarified.

Malipot said Phivolcs monitors one to five volcanic earthquakes daily in Mayon despite this volcano's zero alert.

"Such occurrences are normal," he said.

Volcanic earthquakes help either create or increase crevices in Mayon, however, he noted

He said water can enter Mayon through such crevices, then come in contact with hot volcanic materials, transforming this liquid into steam.

Aside from phreatic eruptions, Phivolcs said lava flows and ashfall are among Mayon Volcano's hazards.

Precursors to Mayon eruptions include increased number of volcanic quakes and emissions there, ground tilt from magma intrusion and crater glow due to presence of magma at or near this volcano's crater, Phivolcs said.

Mayon's last magmatic eruption was in September 2014, the agency said.



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