Tag: volcanoes

Can climate change affect volcanic activity?

Vesuvius is part of a volcanic region that became more active when the Mediterranean Sea dried up about 5 million years ago. A study of the era suggests climate change can influence volcanic activity. @bberwyn photo.

Study suggests link between sea level and eruptions

Staff Report

European researchers say they’ve found more evidence supporting links between climate change and volcanic activity.

Geologists from Switzerland, France and Spain studied compared data on eruptions and climate from about 5 million years ago, finding that volcanic activity in southern Europe doubled during a time when the Mediterranean Sea dried up. They suspect that the changes on the surface contributed to the way magma behaves deep in the Earth.

The era they studied is known as the Messinian salinity crisis, when the Strait of Gibraltar was blocked and the Mediterranean temporarily isolated from the Atlantic, according to the study published in Nature Geoscience.

The geological record shows a sharp increase in volcanic activity, and the scientists concluded the spike can best be explained by the almost total drying out of the Mediterranean.

The trait of Gibraltar was shut on a temporary basis during the Messinian Era (from 5.96 to 5.33 million years ago) and that the Mediterranean Sea was isolated from the Atlantic. Thick layers of salt on the seabed, as well as river canyons carved through land that is now submerged, suggest the Mediterranean Sea’s level was much lower.

The study acknowledges that this hypothesis continues to be a source of debate, while exploring the potential links.

In a statement, University of Geneva geologist Pietro Sternai said it’s clear that changes at the surface of the Earth, like a sudden lowering of sea level, can change the pressure deep down around pockets of molten magma. Based on that, the researchers studied the changes in volcanic activity during the period. Tracing the age of crystals in volcanic deposits, they counted 13 eruptions around the Mediterranean between 5.9 and 5.3 million years ago — more than double the average over comparable time periods.

Why is the figure so high?

“The single logical explanation is the hypothesis that the sea dried out, since this is the only event powerful enough to alter the Earth’s pressure and magmatic production over the entire Mediterranean,” Sternai said.

The team used computer models to simulate the effect of the Mediterranean’s desiccation on pressure at depth and the impact on magma production. According to Sternai, the models show the only way to account for the increased vulcanism was that the level of the Mediterranean Sea dropped by about two kilometres.

Related research has suggested that melting ice sheets in the polar regions, as well as melting glaciers, could also contribute in various ways to increased volcanic activity.

 

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What caused ‘snowball Earth?’

Volcanoes seen as likely trigger for global glaciation

In the right conditions, global ice can spread rapidly from pole to pole. @bberwyn photo.

Staff Report

A 10-year string of steady volcanic eruptions may have been the trigger for a massive global cooling event that left much of the Earth encased in glaciers and ice sheets about 771 million years ago.

The eruptions could have spewed so much sulphur dioxide into the atmosphere that the planet’s climate reached a tipping point, resulting in what scientists call ‘snowball Earth,” according to a new study published this month in Geophysical Research Letters. Understanding the natural variability of climate is important to understanding current climate change driven by emission of greenhouse gases. Continue reading “What caused ‘snowball Earth?’”

Environment: Study quantifies volcano pollution

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Plumes of smoke and flames rise from an eruption at Bárðarbunga volcano, Iceland, in 2014. The amount of sulphur dioxide emitted in the six-month eruption was treble that given off by all of Europe’s industry. Credit Dr. John Stevenson

12,000 tons of sulphur dioxide per day …

Staff Report

Researchers in the UK have helped show how volcanoes can affect air quality by quantifying emissions from last year’s eruption of Iceland’s Bárðarbunga volcano.

“The eruption discharged lava at a rate of more than 200 cubic metres per second, which is equivalent to filling five Olympic-sized swimming pools in a minute,” said Dr Anja Schmidt from the School of Earth and Environment at the University of Leeds, who led the study. Continue reading “Environment: Study quantifies volcano pollution”

More evidence that small volcanoes can slow global warming

Study teases volcanic climate signal out of the noise

Photo courtesy U.S. Fish and Wildlife Service.
Photo courtesy U.S. Fish and Wildlife Service.

Staff Report

FRISCO — A steep, decades-long rise in global temperatures probably was slowed in the late 1990s by the combined effects of a series of small volcanic eruptions, according to a new study led by scientists with Lawrence Livermore National Laboratory.

Previous research suggested that early 21st century eruptions might explain up to a third of the recent global warming slowdown, and the new findings, published in the journal Geophysical Research Letters  further identifies observational climate signals caused by recent volcanic activity, which deflected substantially more solar radiation than previously estimated. Continue reading “More evidence that small volcanoes can slow global warming”

Do small volcanoes have a big climate impact?

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New research may help explain the overall effect of volcanoes on global climate. Photo courtesy USGS.

New research tracks aerosols from volcanic eruptions

Staff Report

FRISCO — Sunlight-reflecting particles from relatively small volcanic eruptions may add up to have a significant effect on global temperatures, according to a new climate study that tries to quantify the cumulative impact of aerosols from volcanoes.

According to the research, based on a combination of measurements taken on the ground, in the air and from satellites, small volcanic eruptions that occurred between 2000 and 2013 deflected almost double the amount of solar radiation previously estimated.

That’s enough to lower global temperatures by about  0.05 to 0.12 degrees Celsius, the scientists concluded in their study, which appears in Geophysical Research Letters. Continue reading “Do small volcanoes have a big climate impact?”

Huge volcanic eruptions can lead to fast climate change

Will the world get it together on climate change?
Researchers are getting a better handle on what might have caused the Permian extinction. Photo courtesy NASA.

Acid rain, ozone depletion contributed to ancient mass extinction

By Summit Voice

FRISCO — While the steady increase in greenhouse gas concentrations may be a slow form of ecocide, massive volcanic eruptions may have the ability to alter the atmosphere so profoundly that it leads to relatively sudden and widespread mass extinctions.

That’s likely what happened 250 million years ago, at the end of the Permian period, when there was a mass extinction so severe that it remains the most traumatic known species die-off in Earth’s history. Previous research has suggested the event was triggered by contemporaneous volcanic eruptions in Siberia, and a recent followup study looked at the effects those eruptions had on Earth’s atmosphere. Continue reading “Huge volcanic eruptions can lead to fast climate change”

New map details Iceland glaciers, sub-glacial volcanoes

New map provides valuable information the global warming era

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Iceland’s glaciers are an important source of water for hydropower generation.

By Summit Voice

FRISCO — A team effort by the U.S. Geological Survey and the Icelandic Meteorological Office has resulted in a new map detailing all of Iceland’s glaciers, as well as subglacial volcanoes. The map incorporates historical data and coverage from aerial photographs and remote sensing satellites, helping to show recent and historic changes in Iceland’s dynamic landscape.

Iceland has about 300 glaciers throughout the country, and altogether, 269 glaciers, outlet glaciers and internal ice caps are named. The glaciers that lack names are small and largely newly revealed, exposed by melting of snow pack due to warmer summer temperatures. The number of identified glaciers has nearly doubled at the beginning of the 21st century. Continue reading “New map details Iceland glaciers, sub-glacial volcanoes”