Taxonomy term

volcanic eruption

Volcanic aerosols not enough to cause mass extinctions?

Mass extinctions — when more than half of Earth’s species disappear in a geologic instant — offer some of the planet’s most perplexing unsolved mysteries. Prolonged periods of volcanic activity have long been prime suspects for these ancient whodunits, the most recent of which finished off the last nonavian dinosaurs at the close of the Cretaceous about 66 million years ago. But scientists debate how drastic the environmental effects of such volcanism might have been, and whether other factors — like asteroid impacts, as in the end-Cretaceous extinction — played a big role as well.

25 Feb 2016

Volcanic eruptions affect rivers around the world

Volcanic eruptions are some of the most powerful agents of climate change on the planet, with some very large events impacting global weather for up to a decade after an eruption. A new study highlights some of the indirect effects of large eruptions, such as how they impact rivers around the world.
 
17 Feb 2016

Permian-Triassic extinctions timed differently on land and at sea

Life on land and in the sea was nearly eradicated about 252 million years ago in the largest-known mass extinction. The cataclysm, known as the Permian-Triassic (P-T) mass extinction, was likely driven by extensive flood basalt volcanism in Siberia and is thought to have affected global biodiversity simultaneously. However, based on analyses of rocks deposited around the time of the P-T boundary in the Karoo Basin of South Africa, scientists suggest in a new study that the terrestrial turnover in vertebrates occurred earlier than the marine extinction. If true, a second trigger — other than Siberian volcanism — might need to have occurred to explain both events.
 
31 Jan 2016

Lake sediments suggest mild volcanic winter after massive Toba eruption

Roughly 74,000 years ago, the largest volcanic eruption of at least the last 2.5 million years — and possibly the last 27 million years — spewed as much as 5,000 cubic kilometers of magma and ash, the latter of which spread far and wide from the source. This catastrophic eruption of the Toba supervolcano on the Indonesian island of Sumatra has long been suggested as a trigger for a precipitous period of global cooling known as a “volcanic winter” that in turn might have driven early humans to the brink of extinction. In a new study, researchers dispute these notions, concluding from an analysis of climate-sensitive microfossils preserved in lake sediments in East Africa — the ancestral home of early humans — that the region experienced little or no cooling following the massive eruption. 
 
10 Jan 2016

Solar flare calibration reveals past patterns of volcanism and cooling

When Mount Pinatubo erupted in the Philippines in 1991, it sent a cloud of ash and sulfuric acid into the atmosphere that blocked incoming solar radiation and caused global temperatures to drop 0.5 degrees Celsius for three years. Quantifying such effects of prehistoric volcanic eruptions on climate, however, has long proved difficult due to inconsistencies in the proxies used to reconstruct atmospheric and temperature fluctuations. In a new study, scientists have used markers left by an unusual solar flare event to align ice-core and tree-ring records, enabling a more accurate accounting of the effects of volcanic eruptions in recent millennia.
 
25 Nov 2015

Jelly volcano reveals eruption trigger

What makes a volcano erupt? Over the years, scientists have proposed a litany of potential triggers, but there’s always room for one more. With help from dyed water, a laser and a tank of clear jelly, researchers have proposed a new mechanism that might push loaded volcanoes toward eruption.
 
03 Oct 2015

Geomedia: Books: Iceland's eruption of biblical proportions explored in 'Island on Fire'

For a few months in 2014–2015, a volcanic eruption in Iceland captivated many people around the world. The Holuhraun lava field produced the largest volume of lava erupted on the North Atlantic island in the past 200 years. Except for the areas plagued with acrid, sulfur-rich gas, which affected air quality, the eruption was mostly harmless and became a tourist spectacle. It was Icelandic volcanism at its finest.
 
16 Jul 2015

Benchmarks: May 8, 1902: The deadly eruption of Mount Pelée

At the turn of the 20th century, the town of St. Pierre was known as the “Paris of the Caribbean.” Nestled into the northwest coast of the French island of Martinique, it boasted a bustling harbor where ships hauled away precious loads of sugar and rum, and it had usurped the official capital — Fort-de-France — as the colony’s cultural center. But St. Pierre had a problem: it lay in the shadow of a massive volcano.

 
08 May 2015

A front-row seat at a fire-and-ice show

Many of the world’s volcanoes are high enough and cold enough to sport seasonal snow, and some even boast year-round glaciers. But what happens when those volcanoes erupt and molten lava hits snow and ice? Observing such extreme interactions of hot and cold is often dangerous in the field, but a slow-moving basaltic eruption in Russia in 2012 provided the right conditions to give scientists a close-up view on one fire-meets-ice display.

 
13 Apr 2015

Chaitén's vigorous volcanic history revealed

When the Chaitén volcano erupted in southern Chile on May 2, 2008, the explosive event took local residents — and geologists — by surprise: Previous studies concluded that the mountain had been quiet for more than 10,000 years. Now, a detailed look at sediments preserved in a nearby lake reveals a much more active history for Chaitén, a finding that may impact the proposed rebuilding of the ash-filled town.

29 Mar 2015

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