Archives par mot-clé : Volcanism

Underground magma triggered Earth’s worst mass extinction with greenhouse gases

by Howard Lee, geologist, August 9, 2017 in WUWT

Earth’s most severe mass extinction, the “Great Dying,” began 251.94 million years ago at the end of the Permian period, with the loss of more than 90% of marine species. Precise rock dates published in 2014 and 2015 proved that the extinction coincided with the Siberian Traps LIP, an epic outpouring of lava and intrusions of underground magma covering an area of northern Asia the size of Europe.

But those rock dates presented science with a new puzzle: why was the mass extinction event much shorter than the eruptions? And why did the extinction happen some 300,000 years after the lava began to flow?

The World’s Five Deadliest Volcanoes… and Why They’re So Dangerous

by Elsevier SciTech Connect, August 2017

Since 1600, 278,880 people have been killed by volcanic activity, with many of these deaths attributed to secondary hazards associated with the main eruption. Starvation killed 92,000 following the 1815 Tambora eruption in Indonesia, for example, and a volcanic tsunami killed 36,000 following the 1883 Krakatoa eruption.

Research shows that volcanic activity has shown no let up since the turn of the 21st century – it just hasn’t been around population centres. Indeed, there remain a number of volcanoes poised to blow which pose a major threat to life and livelihood.

Would a supervolcano eruption wipe us out?

by David Cox, July 24, 2017 in BBC Future

In the Bay of Naples, Europe’s most notorious giant is showing signs of reawakening from its long slumber.

Campi Flegrei, a name that aptly translates as “burning fields”, is a supervolcano. It consists of a vast and complex network of underground chambers that formed hundreds of thousands of years ago, stretching from the outskirts of Naples to underneath the Mediterranean Sea. About half a million people live in Campi Flegrei’s seven-mile-long caldera, which was formed by vast eruptions 200,000, 39,000, 35,000 and 12,000 years ago.

Geologic forces fueling West Antarctica’s Larsen Ice Shelf Cracks

by James Kamis, July 4, 2017 in ClimateChangeDispatch

Geological heat flow is fueling bottom melting and associated cracks across West Antarctica’s Larsen Ice Shelf, having little to do with man-made global warming. Significant amounts of high-quality data and relevant geological observations support this revelation, given historical and current geological mapping efforts done in Antarctica.

                                       see here, image credit NASA

See also here (in French)

‘Bulges’ in volcanoes could be used to predict eruptions

by University of Cambridge, June 28, 2017 in ScienceDaily

Using a technique called ‘seismic noise interferometry’ combined with geophysical measurements, the researchers measured the energy moving through a volcano. They found that there is a good correlation between the speed at which the energy travelled and the amount of bulging and shrinking observed in the rock. The technique could be used to predict more accurately when a volcano will erupt. Their results are reported in the journal Science Advances.

Volcanic eruptions examiner

by University of Iowa, April 19, 2017

in ScienceDaily

The University of Iowa volcanologist spent her days collecting samples from a volcano on Tanna, an island in the remote South Pacific archipelago of Vanuatu. The volcano, called Yasur, spews out flaming masses or “bombs” – some the size of a small car.

This has real health implications,” Ukstins says. “It means more than simply studying volcanoes.”

Also Grand challenges to better prepare for volcanic eruptions