Japan’s Sakurajima Volcano Due For Major Eruption Within 30 Years, Say Scientists

One of Japan’s most active volcanoes is due for a major eruption within the next 30 years, say scientists who have studied a build-up of magma there.

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The Sakurajima volcano on Japan’s Kyushu island poses a “growing threat”, researchers at the University of Bristol say.

The volcano, located 49km (30 miles) from the Sendai nuclear plant, is also close to Kagoshima, a city of 600,000.
Sakurajima’s last deadly eruption was in 1914, when 58 people died.

The Japanese archipelago, which sits on the Pacific “Ring of fire”, has more than 100 volcanoes. Sakurajima regularly spews ash and there are many small explosions there each year, with the latest eruption being in February.

It is closely monitored by Japanese authorities and one of two volcanoes at Level 3 out of 5 levels in Japan’s volcanic warning system, which means that people are warned not to to approach the volcano.

“The 1914 eruption measured about 1.5km cubed in volume,” said the study’s lead author Dr James Hickey, who has now joined the University of Exeter’s Camborne School of Mines.

“From our data we think it would take around 130 years for the volcano to store the same amount of magma for another eruption of a similar size – meaning we are around 25 years away.”

A report on the activity of the volcano was published on Tuesday and teams from Bristol University and the Sakurajima Volcano Research Centre took part

Their research showed that 14 million cubic metres of magma is accumulating each year, enough to fill London’s Wembley Stadium 3.5 times over.

They added that the rate at which the magma is accumulating is faster than it can be expelled in its regular smaller eruptions, which led them to infer that a major eruption is likely in the next 30 years.

They made these assessments based on new ways of studying and modelling the volcano’s magma reservoir. Scientists say they hope these findings can help authorities plan for major eruptions.

“We know that being forewarned means we are forearmed and providing essential information for local authorities can potentially help save lives if an eruption was imminent,” said Dr Hickey.

According to an associate professor at Kyoto University, new evacuation plans have already been prepared.

“It is already passed by 100 years since the 1914 eruption, less than 30 years is left until a next expected big eruption,” said Dr Haruhisa Nakamichi, Associate Professor at the Disaster Prevention Research Institute, Kyoto University.

“Kagoshima city office has prepared a new evacuation plan from Sakurajima.”

Turrialba Volcano Spews Ash, Vapor

Following an increase in seismic activity, Turrialba Volcano began spewing ash, vapor and gases at 2 a.m. on Tuesday, experts from the University of Costa Rica (UCR) and the National University (UNA) confirmed.

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Activity at Turrialba, located in Cartago province 60 kilometers northeast of the capital San José, resumed Monday night with an increase in volcanic tremors, according to a report from UNA’s Volcanological and Seismological Observatory of Costa Rica (OVSICORI).

The report adds that the ash plume from the explosion reached approximately 300 meters (985 feet) above the volcano’s crater.

Mauricio Mora, a volcanologist with UCR’s National Seismological Network (RSN), said windy conditions in the morning dispersed the ash plume towards the west and northwestern areas of the Central Valley. Ashes mainly reached sectors in northeastern San José, and certain areas in Alajuela and Heredia provinces.

People posting on both OVSICORI’s and UNA’s Facebook pages reported smelling sulfur and seeing ash on the ground in communities north and east of the capital including Coronado, Moravia, Guadalupe, Tibás and Montes de Oca.

Tuesday morning’s activity, however, was not as strong as that recorded earlier this year, when ash plumes exceeded 3,000 meters (9,800 ft.) above the volcano.

The new explosion followed 43 days of low activity, after the last important explosion recorded on August 1.

Turrialba is one of Costa Rica’s five active volcanoes along with Arenal, Poás, Irazú, and Rincón de la Vieja.

Aid for farmers

President Luis Guillermo Solís toured communities north and east of Cartago on Monday and announced the allocation of ₡2,4 billion ($4.3 million) for the province, including aid for farmers and ranchers whose production has been negatively affected by volcanic activity and drought in recent years.

According to the Agriculture Ministry, Cartago farmers are the country’s top potato producers, supplying 80 percent of all potatoes consumed in Costa Rica. They are also the largest producers of onions and large suppliers of carrots, yucca, cabbages, beets, flowers and other crops.

Lava Lake Visible Atop Hawaii’s Kilauea Volcano

The U.S. Geological Survey says a lake of lava has come into view atop Hawaii’s Kilauea volcano, and a burst of seismic activity has shaken the summit in recent days.

lava-lake

It’s the first time the lava lake has been visible since May 2015. It deflated Saturday, but it was expected to inflate again Sunday.
At least one earthquake was felt along with several smaller events, according to the Geological Survey.

Kilauea is one of the world’s most active volcanoes. A current lava flow into the Pacific Ocean has drawn thousands of visitors from around the world to Hawaii Volcanoes National Park.

Alert Heightened For Vanuatu Volcano

Vanuatu authorities have upgraded warnings around Ambae Volcano in northern Vanuatu.

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The country’s Geohazards Observatory has raised the alert to Level two on a scale of one to five which signifies the volcano is in a stage of major unrest.

The observatory says volcanic activity could increase at any time over the next few days.

It’s warned the local community, tourists and travel agencies to stay well away from the Manaro crater lakes to avoid the effects of volcanic gas, ash and other volcanic activity.

The Department of Meteorology and Geohazards is closely monitoring the volcano which last erupted in 2009.

Australian Scientists Uncover Evidence Of Super Eruptions 106 Million Years Ago

Australian scientists believe a super volcano active over 100 million years ago was so powerful it spewed tiny crystals across the breadth of the continent.

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It was not exactly the intended area of inquiry for researchers at Curtin University’s School of Mines but they recently stumbled upon the rather fascinating finding nonetheless.

Dr Milo Barham from the Department of Applied Geology led the study, which originally sought to examine the geology of the Nullarbor Plain in remote southeastern WA in order to study how the southern margin of the country evolved after separating from Antarctica.

However once they made the discovery of zircon crystals unlike any previously found in Western Australia, the research took a slightly new direction.

“It was somewhat fortuitous I suppose,” Dr Barham told news.com.au.

Researchers pulled up a vast amount of core material from the drilling to examine the sediment and study certain fossils. They also took a sample of earth to look at zircon crystal and study their chemistry and age to see what sort of rocks the crystals had been eroded from, Dr Barham recalled.

“And then suddenly there were these crystals that didn’t match any thing we know exists in Western Australia and we looked into it more carefully and we see that the chemistry and age match perfectly for what we’d expect for this volcanic region in eastern Australia.”

Using advanced geochemical fingerprinting of individual crystals as well as in-depth analysis of the sediments and their fossils, scientists were able to determine the crystals were the product of volcanic air fall — despite being 2300km from their original source on the other side of the country.

By looking at the age of the material and aspects of their chemistry “we could tell for definite that it came across from the volcanoes on the east coast”, Dr Barham said.

The findings from the dig point to the occurrence of super-eruptions over 100 million years ago.

According to the researchers at Curtin University, such explosive events would have had magnitudes tens to hundreds of times greater than anything in documented human history.

“Such distal projection of a unique volcanic mineral population demonstrates that super-eruptions were occurring in eastern Australia approximately 106 million years ago, during the breakup of the supercontinent Gondwana,” Dr Barham said.

We know about super eruptions in the more recent past. In the last few tens of thousands of years, or maybe a couple million years, he said.

“But trying to go back further to prove these super eruptions is really difficult because it’s very difficult to prove,” he added, because much of the geology from the time has been eroded away.

But given the use of the sophisticated fingerprinting technology, the team is highly confident about their conclusions.

Dr Barham says the findings, which were published in the journal Geology, shine a light on just how violent and volcanic the region was such a long time ago.

These massive eruptions “were not enough to cause any mass extinctions or anything like that but animals would’ve died as a result,” he said.

“It tells us about how violent the east coast of Australia would’ve been at that time.”

Mexico’s Popocatépetl Volcano Erupts 4 Times In Under 24 Hours

MEXICO CITY – Mexico’s National Center for Disaster Prevention said the Popocatépetl volcano has erupted multiple times, spewing ash and burning rocks into the air.

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The disaster prevention center, or CENAPRED, Monday afternoon said Popocatépetl erupted four times in the previous 24 hours, had 73 volcanic plumes and had two volcano tectonic earthquakes — measuring in magnitudes 1.2 and 1.6, respectively.

Popocatépetl is about 43 miles southeast of Mexico City.

CENAPRED in March raised the environmental alert level to the second degree out of three, meaning nearby residents should be prepared to evacuate.

“The CENAPRED urges you not to approach the volcano, especially the crater, due to the danger of falling ballistic fragments,” CENAPRED said in a statement.

Magma Build-Up May Put Salvadoran Capital At Risk

The build-up of magma six kilometres below El Salvador’s Ilopango caldera means the capital city of San Salvador may be at risk from future eruptions, University of Bristol researchers have found.

magmabuildup

A caldera is a large cauldron-like volcanic depression or crater, formed by the collapse of an emptied magma chamber. The depression often originates from very big explosive eruptions. In Guatemala and El Salvador, caldera volcanoes straddle tectonic fault zones along the Central American Volcanic Arc (CAVA). The CAVA is 1,500 kilometres long, stretching from Guatemala to Panama.

The team, from the Volcanology research group at Bristol’s School of Earth Sciences and the Ministry of the Environment and Natural Resources in El Salvador, studied the density distribution beneath the Ilopango caldera and the role tectonic stresses – caused by the movement of tectonic plates along fault lines – have on the build-up of magma at depth. Their study is published today in the journal Nature Communications.

The Ilopango caldera is an eight km by 11 kilometre volcanic collapse structure of the El Salvador Fault Zone. The collapsed caldera was the result of at least five large eruptions over the past 80,000 years.

The last of these occurred about 1,500 years ago and produced enough volcanic ash to form a 15 centimetre thick layer across the entire UK. This catastrophic eruption destroyed practically everything within a 100 kilometre radius, including a well-developed native Mayan population, and significantly disturbed the Mayan populations as far as 200 kilometres away.

The most recent eruptions occurred in 1879–1880 and were on a much smaller scale than the previous one.

Project leader and co-author Dr Joachim Gottsmann said: “Most earthquakes take place along the edges of tectonic plates, where many volcanoes are also located. There is therefore a link between the breaking of rocks, which causes faults and earthquakes and the movement of magma from depth to the surface, to feed a volcanic eruption. The link between large tectonic fault zones and volcanism is, however, not very well understood.”

Existing studies show that magma accumulation before a large caldera-forming eruption, as well as the caldera collapse itself, may be controlled by fault structures.

“However, it is unclear to what extent regional tectonic stresses influence magma accumulation between large caldera-forming eruptions.”, co-author Professor Katharine Cashman said.

Lead author Jennifer Saxby, whose research towards a MSc in Volcanology contributed to the study, said: “Addressing this question is important not only for understanding controls on the development of magmatic systems, but also for forecasting probable locations of future eruptive activity from caldera-forming volcanoes.”

The team discovered that the current tectonic stress field promotes the accumulation of magma and hydrothermal fluids at shallow (< 6km) depth beneath Ilopango. The magma contains a considerable amount of gas, which indicates the system is charged to possibly feed the next eruption.

Dr Gottsmann said: “Our results indicate that localised extension along the fault zone controls the accumulation, ascent and eruption of magma at Ilopango. This fault-controlled magma accumulation and movement limits potential vent locations for future eruptions at the caldera in its central, western and northern part – an area that now forms part of the metropolitan area of San Salvador, which is home to 2 million people. As a consequence, there is a significant level of risk to San Salvador from future eruptions of Ilopango.”