Archives par mot-clé : Volcanism

Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa

by M. Khodri et al., October 3,  2017 in Nature

Stratospheric aerosols from large tropical explosive volcanic eruptions backscatter shortwave radiation and reduce the global mean surface temperature. Observations suggest that they also favour an El Niño within 2 years following the eruption. Modelling studies have, however, so far reached no consensus on either the sign or physical mechanism of El Niño response to volcanism

Global nickel anomaly links Siberian Traps eruptions and the latest Permian mass extinction

by Michael R. Rampino et al., October 2017, in Nature

Anomalous peaks of nickel abundance have been reported in Permian-Triassic boundary sections in China, Israel, Eastern Europe, Spitzbergen, and the Austrian Carnic Alps. New solution ICP-MS results of enhanced nickel from P-T boundary sections in Hungary, Japan, and Spiti, India suggest that the nickel anomalies at the end of the Permian were a worldwide phenomenon.

See also here and here

Submarine Volcanoes etc.

The most productive volcanic systems on Earth are hidden under an average of 8,500 feet (2,600 m) of water. Beneath the oceans a global system of mid-ocean ridges produces an estimated 75% of the annual output of magma. An estimated 0.7 cubic miles (3 cubic kilometers) of lava is erupted. The magma and lava create the edges of new oceanic plates and supply heat and chemicals to some of the Earth’s most unusual and rare ecosystems.

Volcanic eruptions drove ancient global warming event

by Marcus Gutjah et al., August 30,  2017 in PhysOrg

A natural global warming event that took place 56 million years ago was triggered almost entirely by volcanic eruptions that occurred as Greenland separated from Europe during the opening of the North Atlantic Ocean,

The amount of carbon released during this time was vast—more than 30 times larger than all the fossil fuels burned to date and equivalent to all the current conventional and unconventional fossil fuel reserves we could feasibly ever extract.” Ridgwell said.

An unexpected finding was that enhanced organic matter burial was important in ultimately sequestering the released carbon and accelerating the recovery of the Earth’s ecosystem without massive extinctions.

See also here

Discovery of Additional West Antarctic Volcanoes Furthers Natural over Man-Made Warming

by James E Kamis, August 23, in ClimateChangeDispatch

The now three-year-old Plate Climatology Theory is on the brink of total confirmation. This is the result of two just-released and very telling Antarctic research studies. Combining the results of these two studies with the massive amounts of pre-existing data it is possible to show with very high certainty that melting of West Antarctic glaciers is directly related to bedrock heat flow and chemically charged heated fluid flow from the 5,000-mile-long West Antarctic Rift System (see Figure 1).

NASA’s Secret Plan to Save Earth From Super-Volcanoes… Seriously?

by David Middleton, August 18, 2017 in WUWT

If “the supervolcano threat is substantially greater than the asteroid or comet threat,” does this mean we can stop fretting about Gorebal Warming and the Sixth Mass Extinction?  Is NASA really moving on to actual threats to the planet?  Well, not threats to the planet… The planet has handled supervolcanoes, asteroids and comets quite well over its 4.5 billion year lifespan.

Geologists warn us about dangerous volcanoes. Will we spend pennies for warnings?

by Larry Kummer, August 15, 2017

While we obsess about climate change and debate if we live in the Anthropocene, we prepare poorly or not at all for natural forces like volcanoes that can level cities. This is folly we can no longer afford. Experts recommend a simple first step to better protect ourselves. Let’s start listening, or nature will teach us an expensive lesson.

California is the State most at risk due to its volcanoes near major cities, as shown in this map from the website of the California Volcano Observatory

Scientists discover 91 volcanoes below Antarctic ice sheet

by Robin McKie, August 12, 2017 The Guardian

The Edinburgh volcano survey, reported in the Geological Society’s special publications series, involved studying the underside of the west Antarctica ice sheet for hidden peaks of basalt rock similar to those produced by the region’s other volcanoes. Their tips actually lie above the ice and have been spotted by polar explorers over the past century.

See also here and here

Des scientifiques découvrent 91 nouveaux volcans sous les glaciers de l’Antarctique

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.