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Seventeen of 18 volcanoes in Indonesia are on alert status and emitting toxic gas.
The mountains are safe to visit as long as tourists stay at least a half-mile away from the gas-producing craters, Indonesia's Volcanology and Geology Hazard Mitigation Centre said.

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Can volcanoes trigger ice ages?

The idea that a super-enormous volcanic eruption - or hypereruption - would alter the climate dramatically has been around for a long time. It fits the facts about the biggest historical eruptions we know of, and also our understanding both of how volcanoes work and how the atmosphere works. But could the drama extend to tipping the climate from an interglacial state to a full-blown ice age?

The answer, as has long been believed, is still No, according to Alan Robock and colleagues in a paper published last year.

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In 2002, ten of the world's major active ones erupted, including Italy's Etna and Stromboli. In 2003, Mama cut eruptions to six, four of which were in Indonesia. Would she continue the trend? Well, no. In 2004, 26 major volcanoes erupted worldwide in places as far flung as Guatemala, Japan, Mexico, Alaska and, once again, Indonesia.
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Volcanic Lightning
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When volcano seismologist Stephen McNutt at the University of Alaska Fairbanks's Geophysical Institute saw strange spikes in the seismic data from the Mount Spurr eruption in 1992, he had no idea that his research was about to take an electrifying turn.

"The seismometers were actually picking up lightning strikes. I knew that I had to reach out to the physicists studying lightning" - Stephen McNutt.


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When volcano seismologist Stephen McNutt at the University of Alaska Fairbanks's Geophysical Institute saw strange spikes in the seismic data from the Mount Spurr eruption in 1992, he had no idea that his research was about to take an electrifying turn.

"The seismometers were actually picking up lightning strikes. I knew that I had to reach out to the physicists studying lightning" - Stephen McNutt.

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Title: Cold Decade (AD 1810-1819) Caused by Tambora (1815) and Another (1809) Stratospheric Volcanic Eruption
Authors: Jihong Cole-Dai, David Ferris, Alyson Lanciki, Joël Savarino, Mélanie Baroni, Mark H. Thiemens

The extremely cold temperatures during the latter part of the decade from 1810 to 1819 - the coldest decade on record during the past 500 years - have been attributed mainly to the enormous 1815 eruption of the Tambora volcano in Indonesia. Such large volcanic eruptions cool the planet by spewing ash and gases into the stratosphere, where they form sulphate aerosols that block sunlight. But what accounts for the abnormally chilly temperatures earlier in the decade, between 1810 and 1815? Some recent studies have suggested that an unrecorded large volcanic eruption occurred around 1809. To investigate further, Cole-Dai et al. analyse ice cores from Greenland and Antarctica. In the 1809-1810 snow layers, the authors find anomalous sulphur isotopes that must have resulted from chemical reactions that could only have occurred in the stratosphere following a very large volcanic eruption. The results, which help improve understanding of volcanoes' effects on climate, provide the first compelling evidence that an unknown large volcanic eruption occurred in the tropics in early 1809 and contributed to the coldest decade in recorded history.

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Scientists say evidence in the ice of Antarctica and Greenland shows a volcanic eruption, probably near the equator, contributed to global cooling early in the 19th century.
Global warming may be making some people nervous now, but from 1810 to 1819, people worried because the Earth was colder than usual.

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Deep structure imaged under Hawaii

Geologists have obtained the best image yet of a plume of hot rock that rises from Earth's deep mantle and fuels the volcanoes of the Hawaiian islands.
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Hawaiian Hotspot
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Scientists Locate Deep Origins of "Hawaiian Hotspot"

Image showing the topography of the Hawaiian Islands in 3-D.
The Hawaiian Islands are one of the outstanding volcanic features on Earth, but their origins have been shrouded in mystery.
Still in debate has been a theory proposed 40 years ago, which states that mid-tectonic plate hotspots such as Hawaii are generated by upwelling plumes of lava from the base of Earth's lower mantle.

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Previously Unknown Volcanic Eruption Helped Trigger Cold Decade
A team of chemists from the U.S. and France has found compelling evidence of a previously undocumented large volcanic eruption that occurred exactly 200 years ago, in 1809.
The discovery, published online this week in the scientific journal Geophysical Research Letters, offers an explanation as to why the decade from 1810 to 1819 is regarded by scientists as the coldest on record for the past 500 years.

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