Volcanic eruptions slow down climate change - temporarily

Space Daily via SPX: Although global concentration of greenhouse gases in the atmosphere has continuously increased over the past decade, the mean global surface temperature has not followed the same path. A team of international reseachers, KIT scientists among them, have now found an explanation for this slowing down in global warming: the incoming solar radiation in the years 2008-2011 was twice as much reflected by volcanic aerosol particles in the lowest part of the stratosphere than previously thought. ....

For the lowest part of the stratosphere - i. e. the layer between 10 and 16 kilometres - little information was available so far, but now the international IAGOS-CARIBIC climate project combined with satellite observations from the CALIPSO lidar provided new essential information. According to the study, the cooling effect due to volcanic eruptions was clearly underestimated by climate models used for the last Intergovernmental Panel on Climate Change (IPCC) report.

Led by the University of Lund, Sweden, and supported by the NASA Langley Research Center, USA, and the Royal Netherlands Meteorological Institute, three major German atmospheric research institutes were also involved: the Max Planck Institute for Chemistry in Mainz (
MPI-C), the Leibniz Institute for Tropospheric Research in Leipzig (TROPOS) and the Karlsruhe Institute of Technology (KIT). Since more frequent volcanic eruptions and the subsequent cooling effect are only temporary the rise of Earths' temperature will speed up again. The reason is the still continuously increasing greenhouse gas concentration, the scientists say.

..."Overall our results emphasize that even smaller volcanic eruptions are more important for the Earth's climate than expected", summarize CARIBIC coordinators Dr. Carl Brenninkmeijer, MPI-C, and Dr. Andreas Zahn, KIT. The IAGOS-CARIBIC observatory was coordinated and operated by the MPI-C until the end of 2014, since then by the KIT....

Unknown 1830 painting of an eruption in Italy, a Wellcome Image, Wikimedia Commons, under the Creative Commons Attribution 4.0 International license

Famous paintings help global warming experts track climate change over the decades

James Maynard in Tech Times: Paintings from J.M.W. Turner and other artists are being used to track how pollution levels may have changed over time. Investigators are examining what vivid sunrises and sunsets painted by artists could tell us about the environmental effects of volcanic eruptions.

William Turner was born in England in 1775, and lived until 1851. He is best known as a landscape artist, including a wide variety of sunset paintings. The Lake, Petworth sunset, fighting bucks by the artist is one of the paintings investigators examined to clues to ancient eruptions.  In 1815, the Tambora Volcano in Indonesia erupted, spewing thousands of tons of debris into the air. Much of this material traveled around the road, making sunsets and sunrises redder and more dramatic.

Christos Zerefos, from the Academy of Athens in Greece, led the investigation.  "Nature speaks to the hearts and souls of great artists. But we have found that, when coloring sunsets, it is the way their brains perceive greens and reds that contains important environmental information," Zerefos told the press.

Researchers studied 554 paintings of sunsets created between 1500 and 2000. A total of 181 artists created the art works, including Rembrandt, Hogarth, Gainsborough, and Rubens.  "We found that red-to-green ratios measured in the sunsets of paintings by great masters correlate well with the amount of volcanic aerosols in the atmosphere, regardless of the painters and of the school of painting," Zerefos explained.

Greater than normal levels of red predominated in areas affected by volcanic ash, study says. This allows a way of measuring the aerosol optical depth, a total of all the dust, ash and other particulate matter in the atmosphere at a given time....

Turner's "Petworth Park"

Volcanoes contribute to recent warming ‘hiatus’

Alli Gold Roberts in MIT News: By the late 1990s, scientists had observed more than two decades of rapid global warming, and expected the warming trend to continue. Instead, despite continuing increases in greenhouse gas emissions, the Earth’s surface temperatures have remained nearly flat for the last 15 years. The International Panel on Climate Change verified this recent warming “hiatus” in its latest report.

Researchers around the globe have been working to understand this puzzle — looking at heat going into the oceans, changes in wind patterns, and other factors to explain why temperatures have stayed nearly stable, while greenhouse gas concentrations have continued to rise. In a study published today in Nature Geoscience, a team of scientists from MIT and elsewhere around the U.S. report that volcanic eruptions have contributed to this recent cooling, and that most climate models have not accurately accounted for the effects of volcanic activity.

“This is the most comprehensive observational evaluation of the role of volcanic activity on climate in the early part of the 21st century,” says co-author Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT. “We assess the contributions of volcanoes on temperatures in the troposphere — the lowest layer of the atmosphere — and find they’ve certainly played some role in keeping the Earth cooler.”

There are many components of the Earth’s climate system that can increase or decrease the temperature of the globe. For example, while greenhouse gases cause warming, some types of small particles, known as aerosols, cause cooling. When volcanoes erupt explosively enough, they enhance these aerosols — a phenomenon referred to as “volcanic forcing.”...

A 2002 eruption of Mt. Etna viewed from the International Space Station

Volcano discovered smoldering under a kilometer of ice in West Antarctica

Washington University in St. Louis Newsroom: It wasn’t what they were looking for — but that only made the discovery all the more exciting. In January 2010, a team of scientists had set up two crossing lines of seismographs across Marie Byrd Land in West Antarctica....

...There were big questions to be asked and answered. The goal, said Doug Wiens, PhD, was essentially to weigh the ice sheet to help reconstruct Antarctica’s climate history. (Wiens is a professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis and one of the project’s principal investigators.) But to do this accurately, the scientists had to know how the earth’s mantle would respond to an ice burden, and that depended on whether it was hot and fluid or cool and viscous. The seismic data would allow them to map the mantle’s properties.

In the meantime, automated-event-detection software was put to work to comb the data for anything unusual. When it found two bursts of seismic events between January 2010 and March 2011, Wiens’ PhD student Amanda Lough looked more closely to see what was rattling the continent’s bones.... Uncertain at first, the more Lough and her colleagues looked, the more convinced they became that a new volcano was forming a kilometer beneath the ice.

...A colleague suggested that the event waveforms looked like Deep Long Period earthquakes, or DPLs, which occur in volcanic areas, have the same frequency characteristics and are as deep. “Everything matches up,” Lough said.

...Will the new volcano erupt?  “Definitely,” Lough said. “In fact, because the radar shows a mountain beneath the ice, I think it has erupted in the past, before the rumblings we recorded.”

... On the other hand, a subglacial eruption and the accompanying heat flow will melt a lot of ice. “The volcano will create millions of gallons of water beneath the ice — many lakes full,” Wiens said.  This water will rush beneath the ice toward the sea and feed into the hydrological catchment of the MacAyeal Ice Stream, one of several major ice streams draining ice from Marie Byrd Land into the Ross Ice Shelf. By lubricating the bedrock, it will speed the flow of the overlying ice, perhaps increasing the rate of ice-mass loss in West Antarctica....

Melt water from the new volcano will drain into the MacAyeal Ice Stream, labeled above as ice stream E, its original designation. This radar image of West Antarctica (see box on the inset at bottom right for location) has been color-coded to indicate the speed at which the ice is moving. Red marks the fast-moving centers of the ice streams and black lines outline each stream’s catchment area. By greasing the skids with water, the new volcano might increase the rate of ice loss from the MacAyeal Ice Stream. From the Earth Observatory/NASA

Scientists study 'glaciovolcanoes,' mountains of fire and ice, in Iceland, British Columbia, US

Science Daily: Glaciovolcanoes, they're called, these rumbling mountains where the orange-red fire of magma meets the frozen blue of glaciers. Iceland's Eyjafjallajökull volcano, which erupted recently, is but one of these volcanoes. Others, such as Katla, Hekla and Askja in Iceland; Edziza in British Columbia, Canada; and Mount Rainier and Mount Redoubt in the U.S., are also glaciovolcanoes: volcanoes covered by ice.

"When an ice-covered volcano erupts, the interplay among molten magma, ice and meltwater can have catastrophic results," says Sonia Esperanca, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funds research on glaciovolcanoes.

In Iceland last week, scientists were well prepared for the floods, called "jökulhlaups," that can happen after a glaciovolcano blows and melts its glacial covering. The floods were followed by tons of ash ejected into the atmosphere. Most of the rest of the world, however, was unaware that an eruption from a small, northern island in the middle of the Atlantic Ocean could freeze air transportation and stop global commerce in its tracks.

That, say NSF-funded scientists Ben Edwards at Dickinson College and Ian Skilling at the University of Pittsburgh, is the nature of glaciovolcanoes. Understanding volcano-ice interactions occupies much of Edwards' and Skilling's daily lives. They're working at Mt. Edziza in British Columbia, Canada, and in Iceland to find out how glaciovolcanic deposits--rock fragments strewn for miles after an ice-covered volcano erupts--are formed….

This image shows both the eruption plume and the heat signature of lava at the volcano’s summit and at nearby Fimmvörduháls, the site of a precursor eruption. The heat signature shows a rough estimate of temperature, with yellow being hottest and red coolest. The signature at Eyjafjallajökull is a concentrated circle without a river of lava, supporting the Icelandic Coast Guard’s observation that lava had not started to flow from the volcano. Image from NASA

Oh no! Climate change 'may cause eruptions'

Does climate change have to horn in on everything? From the Irish Times: A thaw of Iceland's ice caps in coming decades caused by climate change may trigger more volcanic eruptions by removing a vast weight and freeing magma from deep below ground, scientists said today. They said there was no sign that the current eruption from below the Eyjafjallajokull glacier that has paralysed flights over northern Europe was linked to global warming. The glacier is too small and light to affect local geology.

"Our work suggests that eventually there will be either somewhat larger eruptions or more frequent eruptions in Iceland in coming decades," said Freysteinn Sigmundsson, a vulcanologist at the University of Iceland. "Global warming melts ice and this can influence magmatic systems," he said. The end of the Ice Age 10,000 years ago coincided with a surge in volcanic activity in Iceland, apparently because huge ice caps thinned and the land rose.

"We believe the reduction of ice has not been important in triggering this latest eruption," he said of Eyjafjallajokull. "The eruption is happening under a relatively small ice cap". Carolina Pagli, a geophysicist at the University of Leeds, said there were risks that climate change could also trigger volcanic eruptions or earthquakes in places such as Mount Erebus in Antarctica, the Aleutian islands of Alaska or Patagonia in South America.

"The effects would be biggest with ice-capped volcanoes," she said. "If you remove a load that is big enough you will also have an effect at depths on magma production."…

NASA image by Robert Simmon: Iceland’s Eyjafjallajökull Volcano burst into life for the first time in 190 years on March 20, 2010. A 500-meter- (2,000-foot) long fissure opened in the Fimmvörduháls pass to the west of the ice-covered summit of Eyjafjallajökull. Lava fountains erupted fluid magma, which quickly built several hills of bubble-filled lava rocks (scoria) along the vent. A lava flow spread northeast, spilling into Hrunagil Gully. This natural-color satellite image shows lava fountains, lava flows, a volcanic plume, and steam from vaporized snow.