Volcano Articles

Volcano Articles 2000

Hawaii lava flow draws thousands of spectators - Kilauea July 2002 - AP

Two Oldest Volcanes Found   July 2002 - Ananova News
Geologists in Brazil claim they have found the oldest volcanoes in the world.
The pair are in the Amazon and date back 1.9 billion years.
The oldest previously known volcano was just 500 million years old

Scientists witness birth of new island

Just about to break surface - a new volcanic island

May 25, 2000 - BBC

The dramatic birth of a new volcanic island in the Pacific has been witnessed by an international team of scientists.

The rare event was captured on film by researchers during an expedition to the Solomon Islands.

The Commonwealth Science and Industrial Research Organisation's (Csiro) Research Vessel Franklin, based in Australia, found the Kavachi seamount had entered a new phase of eruptive activity after nine years of apparent dormancy.

Molten ash shot 500 metres (1,600 ft) into the air every five minutes of the team's 20-hour visit.

The peak of the volcano was forming a sandy, ashen beach two metres below sea level, with its regular, violent, bomb-like eruptions.

"We arrived at the seamount site to find waves breaking on the volcanic peak. Violent eruptions were taking place every five minutes," said expedition Chief Scientist Brent McInnes.

Unprecedented opportunity

Kavachi is 35 km (21 miles) from the closest island, in the western Solomons, and was first surveyed in the 1950s.

Dr McInnes said: "It was magma being ejected from the top of a magma chamber, which is below sea level. This magma has a lot of gas in it so it's a very explosive mixture whenever it comes close to the surface.

Neil Cheshire, Master of the RV Franklin, said: "We were able to approach to within 750 m (2,500 ft) of the erupting centre. We found that the volcano had grown dramatically since it was last surveyed in 1984."

Professor Richard Arculus, of the Australian National University Department of Geology, added: "Using Franklin to systematically sample freshly formed volcanic rocks from the flanks of an erupting submarine volcano is an unprecedented opportunity in the field of geology."

And researcher Gary Massoth said: "We detected numerous chemical and particle plumes in the water that extend at least 5 km (16 miles) from the centre of the volcano. This has been a great opportunity for us to obtain fundamental data on dynamic volcanic inputs to the ocean environment"

Supervolcanoes could trigger global freeze

Feb. 3, 2000 - BBC

The threat of climate change caused by human activity could turn out to be a minor problem by comparison with a scarcely acknowledged natural hazard.

Geologists say there is a real risk that sooner or later a supervolcano will erupt with devastating force, sending temperatures plunging on a hemispheric or even global scale.

A report by the BBC Two programme Horizon on one supervolcano, at Yellowstone national park in the US, says it is overdue for an eruption.

Yellowstone has gone off roughly once every 600,000 years. Its last eruption was 640,000 years ago.

Professor Bill McGuire, of the Benfield Greig Hazard Research Centre at University College, London, told BBC News Online: "We're getting ready for another eruption, unless the system has blown itself out.

"But the ground surface deformation and other signs measured by satellite suggest it's still active, and on the move."

Molten rock

Typically, supervolcanoes are not mountains but depressions, huge collapsed craters called calderas, which are hard to detect.

The Yellowstone caldera is 70 kilometres long and 30 km wide. Eight km beneath the Earth's surface lies a huge magma chamber, containing vast amounts of molten rock.

As pressure rises in the chamber, the surface is also rising and there is a measurable increase in heat. But vulcanologists do not know when Yellowstone will blow.

Supervolcanoes are relate to giant calderas

Professor McGuire, whose book, Apocalypse! A natural history of global disasters, portrays a possible Yellowstone explosion in 2074, says there have been two such events every 100,000 years for the last two million years.

The areas where supervolcanoes are most likely to be found, he says, are subduction zones, where the Earth's plates are dipping below one another. The Pacific Rim and southeast Asia are especially vulnerable.

But there is a caldera in the Phlegraean Fields near Naples in southern Italy. Dr Ted Nield, of the Geological Society of London, told BBC News Online: "It could do the same as Yellowstone, though on a smaller scale".

Nuclear winter

"When a supervolcano goes off, it is an order of magnitude greater than a normal eruption. It produces energy equivalent to an impact with a comet or an asteroid.

"You can try diverting an asteroid. But there is nothing at all you can do about a supervolcano.

"The eruption throws cubic kilometres of rock, ash, dust, sulphur dioxide and so on into the upper atmosphere, where they reflect incoming solar radiation, forcing down temperatures on the Earth's surface. It's just like a nuclear winter.

"The effects could last four or five years, with crops failing and the whole ecosystem breaking down. And it is going to happen again some day."

Ice-core records show that the eruption of Toba in Sumatra about 74,000 years ago may have caused global cooling of from three to five degrees Celsius, and perhaps as much as 10 degC during growing seasons in middle to high latitudes.

Even ordinary volcanoes can affect the climate.